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International audience; BACKGROUND: The first-in-class small molecule inhibitor OTX015 (MK-8628) specifically binds to bromodomain motifs BRD2, BRD3, and BRD4 of bromodomain and extraterminal (BET) proteins, inhibiting them from binding to acetylated histones, which occurs preferentially at super-enhancer regions that control oncogene expression. OTX015 is active in haematological preclinical entities including leukaemia, lymphoma, and myeloma. We aimed to establish the recommended dose of OTX015 in patients with haematological malignancies. We report the results from a cohort of patients with lymphoma or multiple myeloma (non-leukaemia cohort). METHODS: In this dose-escalation, open-label, phase 1 study, we recruited patients from seven university hospital centres (in France [four], Switzerland [one], UK [one], and Italy [one]). Adult patients with non-leukaemia haematological malignancies who had disease progression on standard therapies were eligible to participate. Patients were treated with oral OTX015 once a day continuously over five doses (10 mg, 20 mg, 40 mg, 80 mg, and 120 mg), using a conventional 3 + 3 design, with allowance for evaluation of alternative administration schedules. The primary endpoint was dose-limiting toxicity (DLT) in the first treatment cycle (21 days). Secondary objectives were to evaluate safety, pharmacokinetics, and preliminary clinical activity of OTX015. The study is ongoing and is registered with ClinicalTrials.gov, number NCT01713582. FINDINGS: Between Feb 4, 2013, and Sept 5, 2014, 45 patients (33 with lymphoma and 12 with myeloma), with a median age of 66 years (IQR 55-72) and a median of four lines of prior therapy (IQR 3-5), were enrolled and treated. No DLTs were observed in the doses up to and including 80 mg once a day (first three patients). We then explored a schedule of 40 mg twice a day (21 of 21 days). DLTs were reported in five of six patients receiving OTX015 at this dose and schedule (all five patients had grade 4 thrombocytopenia). We explored various schedules at 120 mg once a day but none was tolerable, with DLTs of thrombocytopenia, gastrointestinal events (diarrhoea, vomiting, dysgeusia, mucositis), fatigue, and hyponatraemia in 11 of 18 evaluable patients. At this point, the Safety Monitoring Committee decided to establish the feasibility of 80 mg once a day on a continuous basis, and four additional patients were enrolled at this dose. DLTs (grade 4 thrombocytopenia) was noted in two of the patients. In light of these DLTs and other toxicities noted at 120 mg, the dose of 80 mg once a day was selected, although on a schedule of 14 days on, 7 days off. Common toxic effects reported in the study were thrombocytopenia (43 [96%] patients), anaemia (41 [91%]), neutropenia (23 [51%]), diarrhoea (21 [47%]), fatigue (12 [27%]), and nausea (11 [24%]). Grade 3-4 adverse events were infrequent other than thrombocytopenia (26 [58%]). OTX015 plasma peak concentrations and areas under the concentration versus time curve increased proportionally with dose. Trough concentrations increased less than proportionally at lower doses, but reached or exceeded the in-vitro active range at 40 mg twice a day and 120 mg once a day. Three patients with diffuse large B-cell lymphoma achieved durable objective responses (two complete responses at 120 mg once a day, and one partial response at 80 mg once a day), and six additional patients (two with diffuse large B-cell lymphoma, four with indolent lymphomas) had evidence of clinical activity, albeit not meeting objective response criteria. INTERPRETATION: The once-daily recommended dose for oral, single agent oral OTX015 in patients with lymphoma is 80 mg on a 14 days on, 7 days off schedule, for phase 2 studies. OTX015 is under evaluation in expansion cohorts using this intermittent administration (14 days every 3 weeks) to allow for recovery from toxic effects. FUNDING: Oncoethix GmbH (a wholly owned subsidiary of Merck Sharp & Dohme Corp)

International audience; BACKGROUND: Bromodomain and extraterminal (BET) proteins are chromatin readers that preferentially affect the transcription of genes with super-enhancers, including oncogenes. BET proteins bind acetylated histone tails via their bromodomain, bringing the elongation complex to the promoter region. OTX015 (MK-8628) specifically binds to BRD2, BRD3, and BRD4, preventing BET proteins from binding to the chromatin, thus inhibiting gene transcription. OTX015 inhibits proliferation in many haematological malignancy cell lines and patient cells, in vitro and in vivo. We aimed to establish the recommended dose of OTX015 in patients with haematological malignancies. We report the results of patients with acute leukaemia (leukaemia cohort). METHODS: In this dose-escalation, phase 1 study we recruited patients from seven university hospital centres (in France [five], UK [one], and Canada [one]). Adults with acute leukaemia who had failed or had a contraindication to standard therapies were eligible to participate. OTX015 was given orally at increasing doses from 10 mg/day to 160 mg/day (14 of 21 days), using a conventional 3 + 3 design. In this open-label trial, OTX015 was initially administered once a day, with allowance for exploration of other schedules. The primary endpoint was dose-limiting toxicity (DLT), assessed during the first treatment cycle (21 days). The study is ongoing and is registered with ClinicalTrials.gov, NCT01713582. FINDINGS: Between Jan 18, 2013, and Sept 9, 2014, 41 patients, 36 with acute myeloid leukaemia, a median age of 70 years (IQR 60-75) and two lines of previous therapy, were recruited and treated across six dose levels of OTX015. No DLT was recorded until 160 mg/day, when one patient had grade 3 diarrhoea and another had grade 3 fatigue. However, concomitant grade 1-2 non-DLT toxic effects (ie, gastrointestinal, fatigue, or cutaneous) from 120 mg doses hampered patient compliance and 80 mg once a day was judged the recommended dose with a 14 days on, 7 days off schedule. Common toxic effects for all OTX015 doses were fatigue (including grade 3 in three patients) and bilirubin concentration increases (including grade 3-4 in two patients). OTX015 plasma exposure increased proportionally up to 120 mg/day with trough concentrations in the in-vitro active range from 80 mg/day (274 nmol/L). Three patients (receiving 40 mg/day, 80 mg/day, and 160 mg/day) achieved complete remission or complete remission with incomplete recovery of platelets lasting 2-5 months, and two additional patients had partial blast clearance. No predictive biomarkers for response have been identified so far. INTERPRETATION: The once-daily recommended dose for oral, single agent oral OTX015 use in patients with acute leukaemia for further phase 2 studies is 80 mg on a 14 days on, 7 days off schedule. FUNDING: Oncoethix GmbH, a wholly owned subsidiary of Merck Sharp & Dohme Corp

Our purpose was to determine, in patients with metastatic colorectal carcinoma treated with irinotecan single-agent after 5-FU failure, the most significant predictive parameters for tumour response, progression-free survival and toxicity. Between October 1992 and April 1995, 455 patients with 5-FU resistant metastatic colorectal carcinoma entered four consecutive phase II trials. The first two studies assessed tumour response, the other two were randomized studies which assessed the efficacy of racecadotril to prevent irinotecan-induced diarrhoea. Due to homogeneous main eligibility criterias, data from those studies could be pooled for statistical analysis. Potential clinical and biological predictive factors (PF) for toxicity, tumour growth control, e.g. response or stabilization and progression-free survival (PFS), were studied in multivariate analysis. 363 patients were evaluable for response, 432 were evaluable for PFS, 368 for neutropenia and 416 for delayed diarrhoea, respectively. Normal baseline haemoglobin level (Hb), time since diagnosis of colorectal carcinoma, grade 3 or 4 neutropenia or diarrhoea at first cycle and a low number of organs involved were the most PF for tumour growth control (P< 0.05). Significant prognostic variables for PFS were WHO Performance Status, liver and lymph-node involvement, time since diagnosis, age and CEA value (P≤ 0.02). Six groups of patients based on the number of unfavourable prognostic factors are presented. Baseline bilirubin, haemoglobin level, number of organs involved and time from diagnosis were PF for neutropenia; PS, serum creatinine, leukocyte count, time from 5-FU progression and prior abdominopelvic irradiation were PF for delayed diarrhoea (P≤ 0.05). These PF should help clinicians to anticipate for a given patient the probability to observe a response/stabilization or a toxicity. These results should also be prospectively confirmed in ongoing or future trials using irinotecan, both as a single agent and in combination with other drugs. © 2000 Cancer Research Campaign

Summary Background In phase II studies, irinotecan is active in metastatic colorectal cancer, but the overall benefit has not been assessed in a randomised clinical trial. Methods Patients with proven metastatic colorectal cancer, which had progressed within 6 months of treatment with fluorouracil, were randomly assigned either 300–350 mg/m 2 irinotecan every 3 weeks with supportive care or supportive care alone, in a 2:1 ratio. Findings 189 patients were allocated irinotecan and supportive care and 90 supportive care alone. The mean age of the participants was 58·8 years; 181 (65%) were men and 98 (35%) were women. WHO performance status was 0 in 79 (42%) patients, 1 in 77 (41%) patients, and 2 in 32 (17%) patients. Tumour-related symptoms were present in 134 (71%) patients and weight loss of more than 5% was seen in 15 (8%) patients. With a median follow-up of 13 months, the overall survival was significantly better in the irinotecan group (p=0·0001), with 36·2% 1-year survival in the irinotecan group versus 13·8% in the supportive-care group. The survival benefit, adjusted for prognostic factors in a multivariate analysis, remained significant (p=0·001). Survival without performance-status deterioration (p=0·0001), without weight loss of more than 5% (p=0·018), and pain-free survival (p=0·003) were significantly better in the patients given irinotecan. In a quality-of-life analysis, all significant differences, except on diarrhoea score, were in favour of the irinotecan group. Interpretation Our study shows that despite the sideeffects of treatment, patients who have metastatic colorectal cancer, and for whom fluorouracil has failed, have a longer survival, fewer tumour-related symptoms, and a better quality of life when treated with irinotecan than with supportive care alone.

PURPOSE Irinotecan (CPT-11), a camptothecin derivative, has shown efficacy against colorectal cancer. Delayed-onset diarrhea is its main limiting toxicity. The aim of this study was to determine the pathophysiology of CPT-11-induced delayed-onset diarrhea and assess the efficacy of combined antidiarrheal medication in a phase II, prospective, successive-cohorts, open study. PATIENTS AND METHODS Twenty-eight patients with advanced colorectal cancer refractory to fluorouracil (5-FU) therapy received CPT-11 350 mg/m2 every 3 weeks. The first cohort of 14 consecutive patients explored for the mechanism of diarrhea received acetorphan (a new enkephalinase inhibitor) 100 mg three times daily; the second 14-patient cohort received, in addition to acetorphan, loperamide 4 mg three times daily. Before treatment, and if late diarrhea occurred, patients underwent colon mucosal biopsies for CPT-11 and topoisomerase I levels; intestinal transit time; fecalogram; fat and protein excretion; alpha1-antitrypsin clearance; D-xylose test; blood levels for vasoactive intestinal polypeptide, glucagon, gastrin, somatostatin, prostaglandin E2, and carboxylesterase; CPT-11/SN-38 and SN-38 glucuronide pharmacokinetics; and stool cultures. RESULTS Delayed-onset diarrhea occurred during the first three treatment cycles in 23 patients (82%). Electrolyte fecal measurements showed a negative or small osmotic gap in nine of nine patients and an increased alpha1-antitrypsin clearance in six of six patients. There were no modifications in stool cultures or hormonal dysfunction. Four of 11 patients (36%) with delayed-onset diarrhea in the first cohort responded to acetorphan, whereas nine of 10 patients (90%) responded to the combination of acetorphan and loperamide (P < .02). CONCLUSION CPT-11-induced delayed-onset diarrhea is caused by a secretory mechanism with an exudative component. Early combined treatment with loperamide and acetorphan seems effective in controlling the diarrheal episodes.

PURPOSE A phase I study was undertaken to determine the maximum-tolerated dose (MTD), principal toxicities, and pharmacokinetics of the novel topoisomerase I inhibitor irinotecan (CPT-11). PATIENTS AND METHODS Sixty-four patients meeting standard phase I eligibility criteria were included (24 women, 40 men; median age, 51 years; primary sites: colon, head and neck, lung, pleura; 60 of 64 had been previously treated). Pharmacokinetics was determined by high-performance liquid chromatography (HPLC). RESULTS One hundred ninety CPT-11 courses were administered as a 30-minute intravenous (IV) infusion every 3 weeks (100 to 750 mg/m2). Grade 3 to 4 nonhematologic toxicities included diarrhea (16%; three hospitalizations), nausea and vomiting (9%), asthenia (14%), alopecia (53%), elevation of hepatic transaminases (8%), and one case of skin toxicity. An acute cholinergic syndrome was observed during CPT-11 administration. Diarrhea appeared dose-limiting at 350 mg/m2, but this was circumvented by using a high-dose loperamide protocol that allowed dose escalation. Dose-dependent, reversible, noncumulative granulocytopenia was the dose-limiting toxicity (nadir, days 6 to 9; median recovery time, 5 days). Grade 3 to 4 anemia was observed in 9% of patients. One patient died during the study, 8 days after CPT-11 treatment. Two complete responses (cervix, 450 mg/m2; head and neck, 750 mg/m2) and six partial responses in fluorouracil (5-FU)-refractory colon cancer were observed (260 to 600 mg/m2). Pharmacokinetics of CPT-11 and active metabolite SN-38 were performed in 60 patients (94 courses). CPT-11 plasma disposition was bi- or triphasic, with a mean terminal half-life of 14.2 +/- 0.9 hours (mean +/- SEM). The mean volume of distribution (Vdss) was 157 +/- 8 L/m2, and total-body clearance was 15 +/- 1 L/m2/h. The CPT-11 area under the plasma concentration versus time curves (AUC) and SN-38 AUC increased linearly with dose. SN-38 plasma decay had an apparent half-life of 13.8 +/- 1.4 hours. Both CPT-11 and SN-38 AUCs correlated with nadir leukopenia and granulocytopenia, with grade 2 diarrhea, and with nausea and vomiting. CONCLUSION The MTD of CPT-11 administered as a 30-minute IV infusion every 3 weeks is 600 mg/m2, with granulocytopenia being dose-limiting. At 350 mg/m2, diarrhea appeared dose-limiting, but high-dose loperamide reduced this toxicity and allowed dose escalation. For safety reasons, the recommended dose is presently 350 mg/m2 every 3 weeks; more experience must be gained to establish the feasibility of a higher dose in large multicentric phase II studies. However, when careful monitoring of gastrointestinal toxicities is possible, a higher dose of 500 mg/m2 could be recommended in good-risk patients. The activity of this agent in 5-FU-refractory colorectal carcinoma makes it unique and mandates expedited phase II testing.

Intra-arterial hepatic (i.a.h.) administration of the doxorubicin analogue pirarubicin was evaluated in a phase I trial, based on preclinical studies that showed an advantage of pirarubicin over doxorubicin after locoregional hepatic administration. Pirarubicin was given to 9 patients with metastatic liver disease with intrapatient dose escalation. Of the 58 cycles evaluable for tolerance, no hepatobiliary or vascular toxicity was observed. The doselimiting toxicity was granulocytopenia: the maximum administered doses ranged from 50 to 120 mg/m 2 , suggesting variable rates of pirarubicin hepatic extraction between patients. Pharmacokinetic data obtained in 7 patients, in which a direct comparison of intravenous (i.v.) and i.a.h. administration was possible, indicated a median i.v./i.a.h. ratio of 7.4 for the maximal plasma concentration, and a median ratio of 4 for the area under the plasma concentrations versus time curves, suggesting a high pirarubicin hepatic extraction. An unexpectedly high response rate was observed: two complete (colorectal carcinoma) and two partial responses. These data demonstrate that i.a.h. pirarubicin not only produced high locoregional concentrations and reduced systemic exposure, but can also achieve responses in metastatic liver disease of colorectal origin.

From 1986 to 1990, a multicentric phase II study was conducted with pirarubicin, a new semi-synthetic anthracyclin [4′- O -tetrahydropyranyl-adriamycin (THP)]. 87 patients with advanced gynaecological cancers were treated: epidermoid cervical carcinoma ( n = 31), adenocarcinoma of the endometrium ( n = 28) and ovarian adenocarcinoma ( n = 28). THP was administered by short intravenous infusion, for 3 consecutive days, every 3 weeks. The initial dose of THP was 25 mg/m 2 day (25% of patients) which was then reduced to 20 mg/m 2 day. The average number of courses was 3.7 (range 1–10). The cumulative THP dose was 180 mg/m 2 (range 56–594) in cervix and endometrial tumours and 121 mg/m 2 (range 58–425) in ovarian tumours. Myelosuppression was the major observed toxicity with grade 3–4 leukopenia and thrombocytopenia in 62 and 19% of the patients, respectively. Severe general complications occurred in 6% of the patients with three fatalities due to infections. Gastro-intestinal side-effects were frequent and usually mild (7% of grade 3 vomiting). 48% of the patients showed alopecia, which was complete in 9 cases (10%). 3 patients experienced cardiac events. No significant antitumoral activity was observed in patients who had failed to respod to previous chemotherapy. Promising antitumoral activity was noticed in untreated cervico-uterine carcinomas with 19% partial responses and 12% complete responses (CR). THP activity was lower in endometrial carcinomas (9.5% CR). Results were found to be negligible in ovarian cancer patients, most of them being refractory to previous chemotherapy containing an anthracyclin compound. On the basis of these results, the definite role of THP in gynaecological cancers deserves to be studied in more favourable programmes (e.g. in combined protocols as first-line chemotherapy).

Background: OTX015 (OncoEthix SA, Switzerland) is a novel oral bromodomain and extraterminal (BET) protein family inhibitor, with in vitro and in vivo activity in a variety of hematologic and solid tumor cells. A phase Ib study with OTX015 in patients with hematologic malignancies is underway including a pharmacokinetic (PK) investigation. The PK objectives of this study were to determine the PK profile of oral OTX015 using a population approach. Materials and Methods: A multicenter, dose escalation study in cohorts of 3 to 6 patients with acute leukemia or other hematologic malignancies was performed with a dose escalation step followed by expansion cohorts at the recommended dose. Patients received oral OTX015 from 10 to 160 mg different schedules. PK blood samples from 7 time points were collected over 24 h post-administration on Day 1 for leukemia patients (complete PK) and 4 blood samples over 8 h post-administration for patients with other hematologic malignancies (limited PK). OTX015 plasma concentrations were measured using validated ultra-performance liquid chromatography with tandem mass spectrometry detection with a concentration range 1-250ng/mL. Analyses and population PK (PPK) modeling were performed with the nonlinear mixed effect modeling software program Monolix version 4.3. The following parameters were calculated absorption constant (Ka); apparent distribution volume (V/F); apparent clearance (CL/F) and lean body mass (LBM; calculated considering patient sex, weight and height) was considered as covariate. Results: 85 patients enrolled and treated from January 2013 to August 2014, randomized to six dose levels (10, 20, 40, 80, 120 and 160 mg) QD and 40 mg BID were evaluated. Among them, 81 patients with 630 plasma concentrations (607 + 23 BLQ) were evaluable for PK assessment. A 1-compartment open model adequately described the total OTX015 concentration-time curve. The PPK parameters obtained for the structural model were Ka = 0.74 h−1 (12%); V/F = 71.7 L (6.0%) and CL/F = 8.45 L/h (5.0%). The best correlation between OTX015 AUC values and dose was observed from 10 to 120 mg dose levels (R2 = 0.71). The absorption phase was linear and Tmax was between 1 and 4 h. Mean elimination half-life of OTX015 for all patients was 5.8 h (± 1.1). In the PPK study, the best descriptive model was obtained when LBM was considered in the analysis. A correlation between CL/F and V/F was also observed for OTX015. Conclusions: The PK of OTX015 is best described by a one-compartment model. Preliminary PPK analysis considering only the dose escalation cohort of the Phase I trial indicates that LBM is a good predictor of the OTX015 PK profile. This model should be validated in the ongoing expansion cohorts treated at 80mg QD. Citation Format: Elodie Odore, Francois Lokiec, Maria Eugenia Riveiro, Fabrice Bourdel, Carmen Kahatt, Patrice Herait, Esteban Cvitkovic, Keyvan Rezai. Pharmacokinetics of OTX015 in a phase Ib dose-finding study of patients with hematologic malignancies: Preliminary results of a population PK analysis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4511. doi:10.1158/1538-7445.AM2015-4511

Background: OTX015 (Oncoethix) is a small molecule that specifically binds to BRDs 2, 3 and 4, thereby inhibiting binding to acetylated histones, resulting in downregulation of several oncogenes driven by super-enhancers. The therapeutic potential of BRD inhibitors has been demonstrated in several preclinical models including hematologic malignancies. Methods: The primary end point of this dose escalation study (3 + 3 design) was to establish the Phase 2 recommended dose (P2RD) and schedule in two independent cohorts of patients (pts) with either relapsed/refractory acute leukemia (AL) or other hematologic malignancies (OHM). OTX015 was given orally, daily (qd), with 1 bidaily (bid) dose level (DL) explored, continuously in OHM or for 14 days ON/7 days OFF in AL. Results: From January 2013 to August 2014, 41 pts with AL (AML 37; ALL 3) or high-risk myelodysplastic syndrome (HR-MDS 1) and 45 pts with OHM (22 diffuse large B-cell lymphoma [DLBCL], 11 other lymphomas, 12 multiple myeloma) were enrolled over 7 DLs from 10 to 160 mg. Dose-limiting toxicities (DLT) during the first treatment cycle were observed at doses >120 mg in AL (diarrhea, asthenia) and doses >80 mg in OHM (primarily thrombocytopenia). Additionally, both AL and OHM pts treated at >80 mg experienced grade 1-2 gastrointestinal events (diarrhea, dysgueusia) that hampered compliance, though not meeting DLT criteria. PK showed dose-proportional OTX015 exposure (AUC0-24h) up to 120 mg qd; trough plasma concentrations at 80 mg qd reached the GI50 cut-off of 500 nM for sensitive tumor cell lines in vitro. Two complete remissions (CR) and 1 CR with incomplete recovery (CRi) were observed in pts with relapsed/refractory HR-MDS or AML secondary to MDS and 2 CR and 1 partial response in DLBCL pts. OTX015 P2RD was determined as 80 mg qd with a 14 days ON/7days OFF schedule, based on kinetics of platelet nadir and recovery. Conclusion: OTX015 is an orally available molecule showing dose-proportional exposure up to 120 mg qd with a favorable tolerance profile, and evidence of clinical activity in refractory DLBCL and AML/HR-MDS. Expansion cohorts in AML secondary to MDS, de novo AML and DLBCL at the P2RD are ongoing.

Rationale: BET-bromodomain (BRD) proteins are DNA readers that bind acetylated histone (H) tails preferentially at hyperacetylated superenhancer promoter regions and trigger gene transcription. The expression of several oncogenes, including c-MYC, is epigenetically regulated by BRD. OTX015 is a BRD 2, 3 and 4 inhibitor that prevents BRD binding to acetylated H4 and downregulates gene expression of BRD-dependent genes. OTX015 has been shown to inhibit the growth of diffuse large B-cell lymphoma (DLBCL) cells in vitroand in animal models. Patients & Methods: Patients with non-leukemic hematologic malignancies refractory or resistant to standard therapies were enrolled in an ongoing phase 1 clinical study. Lymphoma patients had to have failed at least two lines of systemic therapy and have evaluable disease. OTX015 was given orally daily (QD) without a planned rest period, with 3-week cycles (cy). Successive cohorts of 3-6 patients were treated at increasing dose levels (DL) from 10 to 120 mg QD to determine the maximum tolerated dose (MTD) or the biologically optimal dose. A BID schedule was tested at DL 4 (40 mg x 2). Pharmacokinetics was assessed on day 1 and residual concentrations were measured on days 2, 8 and 15. Lymphoma assessment was performed according to Cheson’s criteria every 6-8 weeks. Results: From January 2013 to June 2014, 37 non-leukemic patients (18 DLBCL, 9 other lymphomas, 10 myeloma) were treated over 5 dose levels, 33 of whom were evaluable for dose limiting toxicity (DLT). Median age was 67 years (range 27-83), 22 patients were male, 27 patients had ECOG 0-1. Patients had a median of 4 prior therapy lines (range 2-8), including 10 patients with autologous stem cell transplantation. The median number of OTX015 cycles administered was 2 (range 1-10+). No DLTs were observed through DL4 (80 mg QD). Asymptomatic and rapidly reversible grade 4 thrombocytopenia was the DLT at DL4 BID (40 mg x2) and 120 mg QD continuous. Sixteen patients experienced grade 3-4 thrombocytopenia and 3 patients had asymptomatic grade 3-4 neutropenia. Grade 3 non-hematologic toxicities were diarrhea, vomiting, hyperglycemia, and hypernatremia (1 patient each). Other toxicities were non-cumulative grade 1-2 gastrointestinal events (8 patients with diarrhea, 3 dysgueusia, 2 vomiting, 1 nausea, 1 anorexia, 1 abdominal pain), hyperglycemia (7 patients), skin rash (3 patients), asymptomatic coagulation factor VII decrease (2 patients), and direct bilirubin increase (1 patient). Dose proportional plasma concentrations were observed and trough concentrations > 500 nM occurred regularly from 80 mg/day. Additional patients are currently being treated at 80 mg QD or with various discontinuous schedules at 120 mg (5 days on/2 days off, 2 weeks on/1 week off, 1 week on/2 weeks off) to determine the recommended regimen. Clinically relevant activity was reported in 6 patients treated from 40 to 120 mg, including one CR (120 mg, 17+ weeks [wks]) and 1 PR (80 mg, 28 wks), both in DLBCL patients failing 3-4 prior therapy lines, and both with clinical benefit. Four other patients (two with DLBCL, one follicular, and one lymphoplasmacytic lymphoma) had minor tumor shrinkage with clinical benefit (40 mg, 36+ wks; 80 mg, 14 wks; 120 mg 15 wks; 120 mg, 17 wks). Conclusions: OTX015 single agent exhibits clinically significant activity against resistant DLBCL with two responses and two minor tumor shrinkages among nine evaluable patients treated at doses ≥ 80 mg. Centralized pathology review including immunohistochemistry profiling is being performed retrospectively, and will be prospective in a DLBCL expansion cohort. Updated data including recommended regimen and correlations between clinical activity and biomarkers will be presented. Disclosures Thieblemont: Oncoethix SA: Research Funding. Stathis:Oncoethix SA: Research Funding. Inghirami:Oncoethix SA: Research Funding. Karlin:Oncoethix SA: Research Funding. Morschhauser:Oncoethix SA: Research Funding. Gleeson:Oncoethix SA: Research Funding. Broussais:Oncoethix SA: Research Funding. Amorim:Oncoethix SA: Research Funding. Salles:Oncoethix SA: Research Funding. Facon:Oncoethix SA: Research Funding. Cunningham:Oncoethix SA: Research Funding. Vey:Oncoethix SA: Research Funding. Bourdel:Oncoethix SA: Employee of study CRO Other. Herait:Oncoethix SA: CMO and Shareholder Other. Zucca:Oncoethix SA: Research Funding.

Background: Single agent OTX015 has shown activity in several preclinical models of lymphoid tumors, including MCL and MM (AACR 2014), and notably in the ongoing phase I study (AACR 2014). We evaluated the synergy of OTX015 administered in combination with other anticancer compounds in several MCL and MM cell lines. Material and Methods: Two mantle cell lymphoma (REC1, MAVER1) and three multiple myeloma (RPMI8226, U266B1, KMS11) cell lines were exposed to increasing doses of OTX015 alone or in combination with increasing doses of other anticancer drugs. MTT assays were performed after 72 hours exposure. Synergy was assessed by Chou– Talalay combination index (CI) with the Synergy R package: CI < 0.3, strong synergy; 0.3−0.9, synergy; 0.9−1.1, additive effects. Changes in CCND1 protein and mRNA expression after OTX015 exposure were assessed in 4 MCL cell lines (REC1, MAVER1, Granta519, JeKo1). Results: Additive effects were seen in 2/2 MCL cell lines when OTX015 was combined with the demethylating agent 5-AZA (CI = 0.8 and 1), the HDAC-inhibitor vorinostat (CI = 0.8 and 1), and the proteasome inhibitor carfilzomib (CI = 0.8 and 0.9). Whereas, synergy was observed with the BTK-inhibitor ibrutinib in 2/2 MCL cells (CI = 0.7 and 0.4), however in ibrutinib-resistant MAVER1 cells, synergy was only seen with high ibrutinib doses (5−10mM). Synergy was observed in 1/2 MCL cell lines with OTX015 combined with the dual PI3K/mTOR inhibitor BEZ235 (CI = 0.1), the mTOR inhibitor everolimus (CI = 0.5), the glucocorticoid dexamethasone (CI = 0.1), and the immunomodulator pomalidomide (CI = 0.2). CCND1 mRNA and protein levels were not altered in 4/4 MCL cell lines after OTX015 (500 nM) treatment for 4 h and 24 h, suggesting that the antiproliferative activity of OTX015 is not CCND1mediated. Synergy was observed in 3/3 MM cell lines following OTX015 combined with carfilzomib (CI = 0.5, 0.7 and 0.9), or vorinostat (CI = 0.7, 0.6 and 0.7), in 2/3 cell lines with pomalidomide (KMS11, CI = 0.3; RPMI8226, CI = 0.4;) or 5-AZA (KMS11, CI = 0.4; RPMI8226, CI = 0.4) and in 1/3 with dexamethasone (U266B1, CI = 0.4). Conclusions: Preclinical experiments support the exploration of OTX015 combined with other anticancer agents in the clinical setting. Additional studies should be performed to clarify the mechanistic or molecular expression profile associated with sensitivity/resistance to individual combinations.

Background: Lymphomas are still incurable in many patients and novel active compounds are actively being sought. We previously reported single agent activity of the BET bromodomain OTX015 in lymphoma cell lines and in vivo (AACR 2012; ICML 2013). Here, we report a study of the mechanism of action of OTX015 and its activity in combination with other anti-cancer compounds. Methods: Cell lines: 22 diffuse large B-cell lymphoma (DLBCL), 4 mantle cell lymphomas, 3 multiple myelomas, 3 splenic marginal zone lymphoma and 1 prolymphocytic leukemia. Anti-proliferative of OTX015 (OncoEthix SA, Switzerland) was assessed by MTT and its cytotoxic activity by Annexin V staining and gene expression profiling (GEP) with Illumina HumanHT-12 Expression BeadChips. Data mining was done with LIMMA, GSEA, Metacore. Synergy was assessed in cells (2-5 cell lines) exposed for 72 h to increasing doses of OTX015 alone or in combination with increasing doses of other agents. MTT assays were performed and Chou-Talalay combination index (CI) calculated. Results: OTX015 (500 nM, 72h) showed cytostatic activity in 29/33 (88%) cell lines and apoptosis in 3/22 (14%). Mutations in genes coding for MYD88 and components of BCR (P=0.027), and ABC signaling phenotypes (P=0.008) were significantly associated with apoptosis induction. We performed GEP on 2 cell lines (SU-DHL-6, SU-DHL-2), treated with DMSO or OTX015 (500 nM) for 1, 2, 4, 8 or 12 hours. Most upregulated genes were histones. MYC target genes were highly significantly enriched among all OTX015 regulated transcripts and MYC was the most frequently downregulated gene. OTX015 also downregulated MYD88, IRAK1, TLR6, IL6, STAT3, and TNFRSF17, members of the NFKB, TLR and JAK/STAT pathways. NFKB target genes (IRF4, TNFAIP3 and BIRC3) were also downregulated (PCR). Immunoblotting and immunohistochemistry showed a reduction of transcriptionally active pSTAT3 in 2 ABC cell lines, and a reduction in nuclear localization of p50 (NFKB1), indicating an inhibitory effect of OTX015 on the canonical NFKB pathway. Finally, IL10 and IL4 production was reduced after 24 hours OTX015 treatment. Synergy was observed with everolimus (median CI=0.1; range 0.1-0.2), ibrutinib in ABC-DLBCL (CI=0.04; 0.02-0.1), idelalisib (CAL101) (CI=0.5; 0.04-2.4), vorinostat (CI=0.5; 0.3-0.6), rituximab (CI=0.5; 0.4-0.5), decitabine (CI=0.6; 0.6-0.7), lenalidomide (CI=0.7; 0.6-0.7), and all-trans retinoic acid (CI=0.4; .1-1.6). Additive effects were observed for combinations with romidepsin (CI=1.08; 1-1.22), bendamustine (CI=0.92; 0.83-1.1), and doxorubicin (CI=0.83; 0.71-0.96). Conclusions: OTX015 is a promising candidate for targeted combination therapies. A phase I study (NCT01713582) in patients with hematological neoplasias is underway and together with our preclinical data, may support further clinical investigations. Citation Format: Eugenio Gaudio, Elena Bernasconi, Ivo Kwee, Michela Boi, Paola Bonetti, Chiara Tarantelli, Andrea Rinaldi, Monica Testoni, Maurilio Ponzoni, Anastasios Stathis, Georg Stüssi, Eugenia Riveiro, Patrice Herait, Emanuele Zucca, Francesco Bertoni. The BET Bromodomain inhibitor OTX015 targets the NFKB, TLR and JAK/STAT pathways and shows pre-clinical activity as single agent and in combination in mature B-cell tumors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5528. doi:10.1158/1538-7445.AM2014-5528

Background: The human BET family bromodomains, including BRD2-4 and BRDT proteins, has become a druggable target for the development of specific gene transcription inhibitors. Here, we report the preclinical anti-leukemic activity of OTX015 (OncoEthix SA, Switzerland), a novel pan-BET-BRD inhibitor, as single agent and in combination with different drugs. Material and Methods: Eight established human cell lines from acute and chronic myeloid leukemia (AML, i.e. HL-60 and U-937; CML, i.e. K-562 and NALM-1) and acute lymphoblastic leukemia (ALL, i.e. Jurkat, CCRF-CEM, MOLT-3 and -4) were treated by increasing doses of OTX015. The growth inhibition 50% (GI50) values of OTX015 were evaluated by MTT the assay at 72 h. Protein levels were analyzed by Western blot using commercial antibodies. RNA was extracted using the Qiagen RNAEasy and RT-PCR was performed using Fast SYBR Green on a StepOnePlus Real-Time PCR System. Combination effects were evaluated in HL60, U937, Jurkat and K562 cell lines; OTX015 was administered with daunorubicin, azacytidine, dexamethasone, cytarabine or methotrexate. The 48-h combination index (CI) was determined by median effect plot analysis using CalcuSyn software expressed as the median and range of CI values among cell lines (Chou & Talalay analysis). CI1: antagonism. Results: Firstly, the anti-proliferative effect of OTX015 was assessed. In HL60, U937 and Jurkat cells, GI50s values were between 230 and 384 nM, while ≥ 1,000 nM for the remaining cell lines. Both OTX015-sensitive and -resistant cells showed similar basal expression levels of BRD2-4, c-MYC, BCL-2, p21 and Cyclin D1 proteins. In sensitive cell lines, OTX015 caused cell cycle arrest in G1 in a time-dependent manner without induction of apoptosis. Likewise, c-MYC mRNA and protein levels were down-regulated after 6-h and up to 72-h treatments with 500 nM OTX015. In Jurkat cells, OTX015 induced up-regulation of BRD2 and 4 mRNA without modifying protein levels. On the other hand, although the OTX015-resistant cell line K562 showed decreased levels of c-MYC mRNA after 4-h and 24-h exposure, protein levels were constant even after 72 h of treatment. Synergy was observed with daunorubicin in OTX015-sensitive and -resistant cell lines (CI=0.8;0.4-0.9). The combination of OTX015 with azacytine or cytarabine was synergistic (CI=0.6;0.6-0.7 and CI=0.8;0.4-0.9, respectively) despite primary resistance of Jurkat and K562 lines to either of the individual drugs. Methotrexate, dexamethasone and panobinostat exerted synergistic effects with OTX015 in 3 out of 4 cell lines (CI=0.5;0.2-0.9; CI=0.3;0.1-0.7 and CI=0.6;0.5-0.7). Conclusion: Our findings indicate that OTX015 enhances in vitro anti-proliferative effects of standard antileukemic agents supporting combination therapy as an important aspect of the clinical development plan. Citation Format: Lucile Astorgues-Xerri, Ramiro Vázquez, Mohamed Bekradda, Esteban Cvitkovic, Patrice Herait, Eric Raymond, María E. Riveiro. In vitro evaluation of OTX015, a novel pan-BET-bromodomain (BET-BRD) inhibitor, as single agent and in combination with standard chemotherapy drugs in human leukemic cell lines. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5529. doi:10.1158/1538-7445.AM2014-5529

Background: OTX015 is a novel inhibitor of the bromodomain and extra-terminal (BET) protein family. This synthetic oral small molecule targets the BET transcriptional co-activator proteins BRD2/3/4, which are potential cancer targets particularly in hematologic malignancies. A phase Ib study with OTX015 administered to patients with hematologic malignancies was performed including a pharmacokinetic (PK) investigation. The PK objectives of this study were to determine the PK profile and perform a PK/PD modeling of oral OTX015 using a population approach. Materials and Methods: A multicenter, dose escalation study is underway in cohorts of 3 to 6 patients with acute leukemia and other hematologic malignancies. Patients received oral OTX015 at a starting dose of 10 mg once daily (QD). PK blood samples from 7 time points were collected over 24 h post-administration (complete PK) on Day 1 for leukemia patients and 4 blood samples over 8 h post-administration were collected for patients with other malignancies (limited sampling PK). Plasma concentrations of OTX015 were measured using validated Ultra Performance Liquid Chromatography with tandem Mass Spectrometry detection (UPLC-MS/MS) with a concentration range 1 - 250 ng/mL. Analyses and population PK (PPK) modeling were performed with the nonlinear mixed effect modeling software program Monolix version 4.2. Results: From January 2013 to January 2014, 36 patients were treated at four dose levels (10, 20, 40, 80 mg) QD and 40 mg BID. 302 plasma concentrations (289 + 13 BLQ) were analyzed. A 1-compartment open model adequately described the total OTX015 time-concentration curve. The PPK parameters obtained for the structural model were: Ka (absorption constant) = 1.12 h-1; V (distribution volume) = 68.6 L and CL (clearance) = 6.65 L/h with a relative standard error of 27%, 9% and 10% respectively. AUC values for all patients increased dose-proportionally (R²= 0.995). The absorption phase was linear and Tmax was between 1 and 4 hours. Mean elimination half-life of OTX015 for all patients was 7.16 h. The main covariate effects in PPK modeling were body weight (BW) which influenced CL, V. No significant gender influence on PK parameters was observed. Conclusions: The PK of OTX015 is best described by a one-compartment model. BW influenced significantly PK parameters of OTX015. AUC-dose proportionality was observed. Evaluation of glucuronidated metabolite concentrations is ongoing and will contribute to understanding the pathways involved in OTX015 metabolism. PK/PD modeling will be performed to describe toxicity and efficacy (6 experienced clinically meaningful activities) in terms of OTX015 PK. A comparison between QD and BID schemes will be performed in order to verify PK profile of OTX015 for each administration. Citation Format: Elodie Odore, Keyvan Rezai, Eugenia Riveiro, Fabrice Bourdel, Patrice Herait, Esteban Cvitkovic, Herve Dombret, Francois Lokiec. A phase I pharmacokinetic study of OTX015 for the treatment of patients with hematologic malignancies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-231. doi:10.1158/1538-7445.AM2014-LB-231

Aim: The bromodomain and extraterminal (BET) subfamily of human bromodomain (BRD) proteins associates with acetylated chromatin and plays a key role in the epigenetic control of transcriptional activation, notably of genes with super-enhancers, such as the MYC oncogene. OTX015, a potent small molecule inhibitor of BRD2/3/4 (Noel et al, EORTC-NCI-AACR 2013), inhibits proliferation of a wide range of hematologic malignancies (HMs) in vitro (Bonetti et al, EORTC-NCI-AACR 2012; Boi et al, EORTC-NCI-AACR 2013; Braun et al, ASH 2013). This phase I study, designed to determine the recommended dose and pharmacokinetics of oral OTX015 as a single agent, is the first reported clinical study evaluating the effects of BRD inhibition in patients (pts) with HMs. Methods: Two independent cohorts of pts having failed all standard therapies were given ascending oral doses of OTX015 in a conventional 3+3 design, with acute leukemias (AL) treated 14 days on/7 days off and other HMs (OHM) treated continuously in 21-day cycles. OTX015 was given once daily (QD), then twice daily (BID). Results: From Jan to Dec 2013, 16 pts with AL (14 AML, 2 ALL) and 17 with OHM (6 DLBCL, 5 other lymphomas, 6 multiple myelomas) were enrolled over 4 dose levels, 10, 20, 40 and 80 mg QD. Exposure increased dose-proportionally. Plasma trough concentrations at 80 mg QD and 12h concentrations at 40 mg QD were ≥ IC50 values in vitro (250 nM), justifying the shift to a BID schedule. The 40 mg BID cohort is ongoing. Pts have a median age of 70 years (range 32-83) and median of 2 (1-8) prior therapies; 10 of 16 AL pts had AML secondary to pre-existing conditions or chemotherapy. No dose limiting toxicity was observed up to 80 mg QD/40 mg BID. Adverse events (AEs) were mainly grade (G) 1-2 hematologic and gastrointestinal events and diabetes aggravation. G 3-4 AEs were reversible thrombocytopenia in 3 pts with OHM (40 and 80 mg), and neutropenia, diarrhea, and elevated transaminases in 1 pt each. No cumulative toxicity was observed. Nine pts received >3 (range 4-7) cycles without or with minor interruptions. Among 28 pts evaluable for response, 6 had clinically meaningful activity, with 4 of 6 treated at 80 mg. Four pts with refractory/relapsed secondary or post-treatment AML achieved significant peripheral and bone marrow blast decrease or clearance, including 1 complete remission (CR) and 1 CR with incomplete recovery. Among OHM, 1 DLBCL had a partial response (PR) and 1 lymphoplasmacytic lymphoma had metabolic PR on cycle 2 PET-scan. Treatment of 5 of 6 responding pts is ongoing. Responses occurred in pts with various clinical, cytogenetic and molecular profiles. Conclusion: OTX015 is the first BRD inhibitor demonstrating clinical activity. Maximum tolerated dose was not reached at 80 mg QD or 40 mg BID; dose escalation is ongoing with the BID schedule and further schedule optimization. Updated results will be presented. Citation Format: Patrice E. Herait, Celine Berthon, Catherine Thieblemont, Emmanuel Raffoux, Valeria Magarotto, Anastasios Stathis, Xavier Thomas, Xavier Leleu, Carlos Gomez-Roca, Elodie Odore, Christophe Roumier, Fabrice Bourdel, Bruno Quesnel, Emanuele Zucca, Mauricette Michallet, Christian Recher, Esteban Cvitkovic, Keyvan Rezai, Claude Preudhomme, Thierry Facon, Antonio Palumbo, Herve Dombret. BET-bromodomain inhibitor OTX015 shows clinically meaningful activity at nontoxic doses: interim results of an ongoing phase I trial in hematologic malignancies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT231. doi:10.1158/1538-7445.AM2014-CT231

Summary Background In phase II trials, irinotecan is active in patients with advanced colorectal cancer, but the survival and clinical benefit of irinotecan compared with secondline fluorouracil by continuous infusion is not known. Methods 267 patients who had failed to respond to firstline fluorouracil, or whose disease had progressed after treatment with first-line fluorouracil were randomly allocated irinotecan 300–350 mg/m 2 infused once every 3 weeks or fluorouracil by continuous infusion. Treatment was given until disease progression, unacceptable toxic effects, or the patient refused to continue treatment. The primary endpoint was survival, while progression-free survival, response rate, symptom-free survival, adverse events, and quality of life (QoL) were secondary endpoints. Findings 133 patients were randomly allocated irinotecan and 134 were allocated fluorouracil by continuous infusion. Patients treated with irinotecan lived for significantly longer than patients on fluorouracil (p=0·035). Survival at 1 year was increased from 32% in the fluorouracil group to 45% in the irinotecan group. Median survival was 10·8 months in the irinotecan group and 8·5 months in the fluorouracil group. Median progression-free survival was longer with irinotecan (4·2 vs 2·9 months for irinotecan vs fluorouracil, respectively; p=0·030). The median pain-free survival was 10·3 months and 8·5 months (p=0·06) for irinotecan and fluorouracil, respectively. Both treatments were equally well tolerated. QoL was similar in both groups. Interpretation Compared with fluorouracil by continuous infusion second-line irinotecan significantly improved survival in patients with advanced colorectal cancer.

PURPOSE To assess, on a multicenter basis, the feasibility of treating advanced cancer patients with high-dose irinotecan. PATIENTS AND METHODS Thirty-five patients who met the usual phase I criteria (26 men and nine women) were included. Primary tumor sites were colon, head and neck, unknown primary, kidney, liver, and others. All had been previously treated. Irinotecan was given at the maximum-tolerated dose (MTD) (600 mg/m2) or the level below (500 mg/m2) as a 30-minute infusion once every 3 weeks. RESULTS Eighteen patients were entered in the four participating centers at the MTD of 600 mg/m2. This dose level was clearly shown not to be feasible: 14 patients (78%) had grade 3 to 4 neutropenia, with febrile episodes in 11 patients; grade 3 to 4 diarrhea was observed in nine patients; and one toxic death occurred. Subsequently, 17 not heavily pretreated patients were included at 500 mg/m2 and carefully monitored. The safety of this dose level was considered acceptable: 41% of patients had grade 3 to 4 neutropenia, 24% experienced grade 3 to 4 diarrhea, and no febrile granulocytopenia or toxic death occurred. Six partial responses were documented in metastatic colorectal cancer, all in patients who had previously received conventional chemotherapy, four in patients who had exhibited progressive disease under fluorouracil (5FU)-based chemotherapy. CONCLUSION We plan to study the higher dose-intensity 500-mg/m2 level on good-risk and carefully monitored patients. This could enlarge the spectrum of tumors sensitive to irinotecan and improve the already good results observed in colorectal cancers.

PURPOSE To assess the efficacy of irinotecan (CPT-11) in the treatment of advanced colorectal cancer in both chemotherapy-naive and pretreated patients. PATIENTS AND METHODS Two hundred thirteen patients (aged 18 to 75 years) with metastatic colorectal cancer, World Health Organization (WHO) performance status < or = 2, and life expectancy > or = 3 months were treated with CPT-11 350 mg/m2 every 3 weeks. All 178 patients eligible for efficacy analysis had not received more than one prior fluorouracil (5-FU)-based chemotherapy regimen (adjuvant or palliative) and had adequate hematologic, renal, and hepatic function. RESULTS Primary tumor sites were the colon (71%) and rectum (28%). Sixty-six percent of the patients had > or = two metastatic sites. Ninety-eight percent of the patients had undergone previous surgery, and 77.5% had received prior chemotherapy. Thirty-two of 178 eligible patients achieved on objective response (four complete responses [CRs] and 28 partial responses [PRs]; response rate, 18%; 95% confidence interval, 12.6% to 24.4%), 65 were stable, and 59 progressed. The response rate was 17.7% in the pretreated group and 18.8% in the chemotherapy-naive group. Within the former subgroup, response rates of 16.1% were reported in patients who were progressive on prior 5-FU chemotherapy and 19.1% in patients who were progressive off such treatment. The median duration of objective response (9.1 months) and median time to achievement of a response (9.3 weeks) did not differ between chemotherapy-naive and pretreated patients. The most frequent adverse events were neutropenia, which developed in 80% of the patients, delayed diarrhea (87%), alopecia (88%), fatigue (81%), and nausea/vomiting (77%). All these adverse events were manageable. Severe (WHO grade 3 or 4) neutropenia was only observed in 18% of the cycles, leukopenia in 11%, delayed diarrhea in 11%, and nausea and vomiting in 3%. Development of simultaneous grade 3 or 4 neutropenia and delayed diarrhea during 4% of the cycles was the safety issue of greatest concern. CONCLUSION CPT-11 has definite activity in the treatment of advanced metastatic colorectal cancer both in chemotherapy-naive and in pretreated patients who experienced disease progression on 5-FU, which suggests a lack of cross-resistance between CPT-11 and 5-FU. Diarrhea and neutropenia, the major toxicities of CPT-11, contribute to the risk to develop febrile neutropenic sepsis.

Background: Gal-1 is a lectin with multiple biological functions including tumor progression, migration, and angiogenesis. OTX008, a small molecule downregulating gal-1 protein level, displays direct antiproliferative and anti-invasive effects in human cancer cells. Objectives: Determine the maximum tolerated dose (MTD) of single agent OTX008 using a subcutaneous (SC) daily dosing based on dose-limiting toxicities (DLTs). Secondary objectives were safety, pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity. Patients and Methods: Patients (pts) with solid tumors having failed standard therapies, and given a written consent were enrolled. OTX008 was delivered as daily SC injection. In case of DLT, treatment was interrupted until recovery and resumed at the dose level (DL) below. Dose was escalated according to a 3+3 design. The MTD was defined as the highest DL, in which ≤1/6 pt experiences a DLT. Results: 22 pts (50% with colorectal carcinoma) were treated from March 2012 to March 2013. Six were enrolled at DL1 (65mg-flat dose) without DLT. Among the 7 pts enrolled at DL2 (120-130mg), 2 experienced DLT. DL2 was therefore deemed to exceed the MTD and 9 additional pts were enrolled at DL1. No DLT was observed among the 15 patients treated at DL1. The most frequent related adverse event (AE) was G1-2 injection site reaction in 20 patients. Two pts experienced skin ulcerations, resulting in subcutaneous abscess and treatment discontinuation in one and consent withdrawal in another. Transient and fully reversible neurological AEs were observed in 12 pts (55%), and were more frequent (100% vs 33%) and more severe (G3 in 29% vs 0%) at DL2 compared to DL1 respectively. G 1-2 tremor was observed in 8 pts, perioral paresthesia in 5, dizziness in 4 and myoclonia in 2. Two patients experienced G3 ataxia (DLT), and one patient with past history of post-traumatic epilepsy experienced G3 seizure. Gastrointestinal (GI) AEs were reported by 12 pts (55%); G3 vomiting/abdominal pain and G3 diarrhea were reported in 1 pt each; 12 patients developed asymptomatic abnormal lab values (10 hypomagnesemia and 8 transient elevation of CPK without rhabdomyolysis or cardiac ischemia). OTX008 plasma concentrations were >1µM over 12h after administration. PK of OTX008 is best described by a two compartment open model and showed less than proportional exposure increase, possibly due to wide inter-patient variability. The main covariate effect was related to body weight. Plasma gal-1 levels decreased proportionally with increasing OTX008 plasma concentrations. Serial tumor biopsies in 6 patients did not conclude on a PD effect. No objective response was reported. Conclusions: OTX008 recommended flat daily sc dose is 65mg, which achieves significant systemic plasma concentrations based on in vitro models. Weight adapted dosing may optimize systemic exposure. Local tolerance of SC injection is poor.Reversible ataxia was a dose-limiting toxicity. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A72. Citation Format: Jean-Pierre Delord, Ahmad Awada, Eric Raymond, François Lokiec, Patrice Herait, Keyvan Rezai, Nicolas Lachaux, Gabriel A. Rabinovich, Carlos Gomez-Roca, Philippe Aftimos, Sandrine Faivre, Juan Carlos Stupirski. A first-in-man Phase I study of the galectin-1 (gal-1) inhibitor OTX008 given subcutaneously as a single agent to patients with advanced solid tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A72.

Background: Galectin-1, a multifunctional lectin, modulates cancer cell proliferation and tumor angiogenesis. OTX-008, a synthetic calixarene molecule, binds directly to galectin-1 and induces a conformation change in reduces galectin-1 binding to carbohydrates. In vitro pharmacodynamic studies showed that OTX008, at micromolar concentrations, inhibited agglutination, proliferation, and invasion of cultured cancer cells. Objectives of the ongoing OTX008 phase I study are: determine the recommended dose, pharmacokinetics (PK), pharmacodynamics (PD) and a PK/PD modeling of OTX008 given subcutaneously (SC) in humans. Materials and Methods: This is a multicenter, dose escalation, open label, phase I study in successive cohorts of 3 to 6 evaluable patients treated with OTX008. Nine time point blood samples were collected on D1 of cycle 1 and two blood samples, just before and 1 hour after OTX008 administration (Cmin/Cmax) were collected on D2 and D22. Urine samples were collected during the first 24 hours after D1 administration. At the first DL (65 mg OTX008 sq qd), tumor samples also were obtained from a patient with advanced, heavily pre-treated cutaneous angiosarcoma of the scalp at baseline and at D22. Plasma, urine and tumor concentrations of OTX008 were measured using a validated Ultra Performance Liquid Chromatography with tandem Mass Spectrometry detection (UPLC-MS/MS) with range of 5 - 250 ng/mL. Pharmacokinetic analyses were carried out using the nonlinear mixed effect modeling software program Monolix version 4.1. Results: PK profiles of 7 patients treated at DL1 (65 mg) are reported. A 2-compartment open model adequately described the total OTX008 time-concentration curve with linear elimination. Following D1 administration, mean + SD Cmax was 4666 + 2012 ng/ml; and Tmax ranged from 0.5 h to 2 h; mean + SD AUC was 48.9 + 36.8 mg.h/l and mean + SD T1/2 was T1/2=5.5 + 0.9 h. Prior to D2 dosing, all patients had OTX008 plasma concentrations ≥1 μM. No accumulation was observed, steady state was reached around D22 after drug administration; 8-10 % of dose was recovered in urine during the first 24 hours. In one patient assessed, the intra-tumor concentration of OTX008 at D22 was 0.002 nM/mg of tumor. DL2 130mg sq qd ongoing (ongoing) and 65 mg bid schedule (planned) will be assessed and also presented. Conclusions: Our DL1 results show that OTX008 is rapidly absorbed and distributed after single SC administration. The PK of OTX008 is best described by a two compartment open model. The influence of BMI will be studied with further DL cohorts and larger number of patients. Urinary excretion seems to be the major route of unchanged drug elimination. High plasma concentrations, close to the active dose in vitro were achieved from DL1. Citation Format: Keyvan Rezai, Sylvere Durand, Nicolas Lachaux, Eric Raymond, Patrice Herait, Francois Lokiec. OTX008 pharmacokinetics (PK) during the first-in-man phase I study in patients with advanced solid tumors . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 33. doi:10.1158/1538-7445.AM2013-33

Colorectal cancer is one of the most common cancers in the Western World. Although 50% of patients are cured by surgery alone, the outcome is poor in high-risk patients (Dukes stages B2 and C) despite adjuvant chemotherapy with 5-fluorouracil (5-FU)-based regimens. CPT-11 (irinotecan) is a promising new agent for the treatment of colorectal cancer with a unique mechanism of action. CPT-11 is a DNA topoisomerase I inhibitor, which has not demonstrated susceptibility to the P-glycoprotein-mediated multidrug-resistant phenotype. Phase II studies with CPT-11 have demonstrated definite activity against colorectal cancer in both chemotherapy-naive and pretreated patients (response rates of 15-32% observed) even with clinical evidence of resistance to 5-FU. The response rate appears to be consistent, reproducible and equivalent to that achieved with 5-FU plus folinic acid in chemotherapy-naive patients.

Summary Background Irinotecan (CPT-11) is a novel water-soluble camptothecin derivative selected for clinical testing based on its good in vitro and in vivo activity in various experimental systems, including pleiotropic drug-resistant tumors. Its mechanism of action appears mediated through topoiso-merase I inhibition. The purpose of this study was to describe CPT-11 and active metabolite SN-38 population pharmacokinetics, examine patient characteristics that may influence pharmacokinetics, and to investigate pharmacokinetic-phar-macodynamic relationships that may prove useful in the future clinical management of this drug. Patients and methods As part of 3 Phase I studies including 235 patients, pharmacokinetics of CPT-11 and metabolite SN-38 were determined in 107 patients. CPT-11 was administered as a 30-min i.v. infusion according to 3 different schedules: daily for 3 consecutive days every 3 weeks, weekly for 3 weeks, and once every 3 weeks. Patients characteristics were the following: median age 53 years; men, 45 women; 105 Caucasians, 2 blacks; performance status was 0–1 in 96 patients; tumor sites were predominantly colon, rectum, head and neck, lung, ovary and breast; with the exception of 6 patients, all had been previously treated with surgery, chemotherapy and/or radiotherapy. CPT-11 and metabolite SN-38 were simultaneously determined by HPLC using fluorescence detection. Pharmacokinetic parameters were determined using model-independent and model-dependent analyses. Results 168 pharmacokinetic data sets were obtained in 107 patients (97 first courses, 43 second courses, 23 third courses, 4 fourth courses, and 1 fifth course). Rebound concentrations of CPT-11 were frequently observed at about 0.5 to 1 h following the end of the i.v. infusion, which is suggestive of enterohepatic recycling of the drug. Model-independent analysis yielded the following mean population pharmacokinetic parameters for CPT-11: a terminal half-life of 10.8 h, a mean residence time (MRT) of 10.7 h, a volume of distribution at stedy state (Vdss) of 150 L/m2, and a total body clearance of 14.3 L/m2/h. Model-dependent analysis disclosed a CPT-11 plasma disposition as either biphasic or tri-phasic with a mean terminal half-life of 12.0 h. The volume of distribution Vdss (150 L/m2) and total body clearance (14.8 L/m2/h) yielded almost identical values to the above model-independent analysis. The active metabolite SN-38 presented rebound concentrations in many courses at about 1 h following the end of the i.v. infusion which is suggestive of enterohepatic recycling. The mean time at which SN-38 maximum concentrations was reached was at 1 h since the beginning of the 0.5 h infusion (i.e., 0.5 h post i.v.). SN-38 plasma decay followed closely that of the parent compound with a mean apparent terminal half-life of 10.6 h. Mean 24 h CPT-11 urinary excretion represented 16.7% of the administered dose, whereas metabolite SN-38 recovery in urine was minimal (0.23% of the CPT-11 dose). The number of CPT-11 treatments did not influence pharmacokinetic parameters of either the parent compound or metabolite SN-38. Although CPT-11 pharmacokinetics presented an important interpatient variability, both CPT-11 maximum concentrations (Cmax) and the CPT-11 area under the plasma concentration versus time curves (AUC) increased proportionally and linearly with dosage (Cmax, r=0.78, p Patient physio-pathological characteristics were examined as possible determinant of pharmacokinetics. No detectable relationship was observed between CL or the metabolic ratio (% SN-38 AUC/CPT-11 AUC), with the following physio-pathological factors: age, sex, height, weight, body surface, tumor type, or renal function. However, with regard to hepatic function, significant correlations (negative) were observed with CPT-11 CL and some hepatic function markers, e.g., bilirubinemia and gamma-glutamyl transpeptidase. Also of interest, a significant positive correlation between the metabolic ratio and some liver function parameters were observed, e.g., bilirubinemia, aspartate transferase (AST), and alanine transferase (ALT). For the pharmacokinetic-pharmacodynamic studies, CPT-11 AUC correlated significantly with the percent decrease of either the white blood cells or the neutrophils. CPT-11 AUC also correlated significantly with the intensity of diarrhea, and the intensity of nausea and vomiting. CPT-11 CL correlated negatively with the intensity of the principal toxicities observed. Metabolite SN-38 AUC was also significantly correlated with the percent decrease in white blood cells and neutrophils. Significant correlations were also observed between SN-38 AUC and the intensity of diarrhea, and the intensity of nausea and vomiting. The metabolic ratio did not correlate with any of the principal toxicities encountered in these clinical studies. With regard to antitumor responses, although the optimal schedule and dose were not obviously defined at the beginning of these phase I trials, 17 tumor responses were nevertheless observed (2 complete, 9 partial, 6 minor). The observation that most of these responses were obtained at the highest doses administered is highly suggestive of a dose-response relationship with this drug. Conclusions These data indicate that CPT-11 population pharmacokinetics is linear within the large dose range investigated, that the number of treatments do not influence pharmacokinetics, that liver function affects CPT-11 clearance. Also of interest, the intensity of the major toxicities encountered with this drug (e.g., leukoneutropenia, diarrhea, nausea and vomiting) correlated with the exposure (AUC) to CPT-11 and metabolite SN-38. A dose-effect relationship was also noted for anticancer activity since most tumor responses were observed at the highest doses administered. These pharmacological data are of importance for the conduct of future clinical studies with this active drug.

Background. Galectin-1 binds neuropilin-1, enhances VEGFR2 signalling, and contributes to membrane anchorage of H-RAS in cancer cells. Those effects may modulate cancer cell proliferation, apoptosis, and tumor angiogenesis. OTX-008 is a non-peptide chemical antagonist designed to bind galectin-1. We previously showed that OTX-008 displays direct antiproliferative effects and inhibits galectin-1 expression in cancer cell lines (AACR 2011, Abstract n°685). In this study we focused on the antitumor and antiangiogenic effects of galectin-1 inhibition by OTX-008 or shRNA in xenograft models. Material and Methods. A2780-1A9 (1A9) ovarian cells, head and neck SQ20B and SQ-shGAL-1 (SQ20B transfected with shGalectin-1 RNA) cells were injected s.c. into female nu/nu athymic mice. When tumors became palpable, 1A9- and SQ20B- mice were treated with vehicle (PBS) or 5-10 mg/kg OTX008 i.p. q.d for 3 weeks. At the end of treatment, mice were sacrificed and tumors collected. Immunohistochemistry was performed on OCT-embedded tumor stained with H&E, galectin-1, MIB1 (Ki67), VEGFR2 or CD31. Image quantification was done with Histolab software (Microvision, France) subtracting the background. Results. OTX-008 inhibited tumor growth in both 1A9 and SQ20B xenografts after 21 days of treatment. A major decrease in the number of secondary tumors development was observed in SQ20B xenografts. A decrease in galectin-1 expression was seen in treated tumors respect to control tumors (1A9: 11.103 +/− 2.103 µm2 vs 26.103 +/− 6.103 µm2, p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1926. doi:1538-7445.AM2012-1926

Background Diarrhea is a serious side effect that may prevent the administration of high doses of the antitumor drug Irinotecan (CPT-11). Purpose Intensive, high-dose loperamide was used in an attempt to control or downstage CPT-11-induced diarrhea and thus permit the use of higher dose intensities of CPT-11. Methods Twenty-three patients with various cancers were treated with doses of CPT-11 ranging from 400 to 600 mg/m2, administered as a 30-minute intravenous infusion every 3 weeks. Starting 8 hours or more after the administration of CPT-11, any episode of diarrhea was treated with 2 mg of loperamide taken every 2 hours. Patients stopped taking loperamide only after a 12-hour diarrhea-free period. If diarrhea was not controlled after 3 consecutive days of nonstop loperamide intake, or if the patient was dehydrated, loperamide was stopped and the patient was hospitalized for intravenous fluids. If blood or mucus were found in the stools at any time during diarrhea, loperamide was stopped and the patient was hospitalized. Results Seventeen of 23 patients had diarrhea while on CPT-11 treatment. Eighty-two CPT-11 cycles were administered to these 17 patients, and diarrhea occurred in 49 of these cycles, at a median time-to-onset of 6 days after CPT-11 administration. The loperamide protocol was followed in 46 of the 49 episodes of diarrhea, with 21 capsules of loperamide the median number being taken (range, 5-72). Only one patient was hospitalized for failure to respond to loperamide, and no major toxicity was associated with loperamide use. Fourteen of the 17 patients who experienced diarrhea were rechallenged with CPT-11 three or more times, and seven patients six or more times. Conclusions High-dose loperamide controlled diarrhea in patients receiving CPT-11 and allowed administration of higher doses of CPT-11. Implications The effectiveness of CPT-11 might be increased by higher dose intensities, which can be made tolerable by control of diarrhea with loperamide.

Eighteen patients with either metastatic or locally advanced pancreatic carcinoma were treated with intravenous infusion of Pirarubicin 50 mg/m2/day every 3 weeks. Seventeen patients were evaluable for response. One had minor response, 5 had stable disease, and 11 had progression of disease. Hematological toxicity was moderate, leading to a dose reduction in only 1 patient; there was no clinical cardiac toxicity. We conclude that Pirarubicin used with this dosage and schedule has no activity in advanced pancreatic carcinoma.

Background. Sensitivity to targeted agents inhibiting VEGFR/PDGFR signaling, including sunitinib, may be dependent of the concomitant modulation of alternative survival pathways. The lectin galectin-1 (gal1) is overexpressed in several tumors, selectively binds neuropilin-1 and enhances VEGFR2 signaling thereby activating the MAPK and/or AKT pathways in cancer cells. Those effects may result in modulation of cancer cell proliferation, apoptosis, cell cycle, and tumour angiogenesis. Optimizing the inhibition of gal1/neuropilin-1/VEGFR-dependent signaling may be a useful approach to improve the activity of multitargeted drugs in cancer cells. The aim of the present study was to evaluate the effects of PTX-008, a novel drug that targets gal1, alone or in combination with sunitinib on several human cancer cell lines. Material and Methods. Antiproliferative effects were evaluated in human colon, breast, ovarian, head & neck, lung, prostate and HCC cancer cell lines by MTT assay. Effects of PTX-sunitinib combinations were determined by median effect plot analysis (Chou & Talalay). Results. Antiproliferative effects of sunitinib as single agent were evaluated on a panel of 20 human cancer cell lines including SQ20B, COLO205 and HT29 with IC50=2; 3 and 8µM, respectively. Antiproliferative effects of single agent PTX-008 were detected in several cell lines including head & neck SQ20B, colon HT29 and COLO205, lung HOP62 and ovarian cancer cells OVCAR3 and IGROV1 with GI50 of 3; 9; 9; 27; 3 and 27µM respectively. In contrast, head & neck HEP2, prostate DU145, breast MCF7 and SKBR3, renal CAKI1, hepatocarcinoma SK-HEP1 and colon HCC2998 lines appear to be resistant to PTX-008 (GI50>27µM). Effects of PTX-008 were slowing cell proliferation and G2/M accumulation, along with blockage of ERK and AKT survival pathways. In order to evaluate the effects of PTX-008 in combination with other multitargeted inhibitors, we used sequential and simultaneous exposure to PTX-008 with sunitinib. Combinations of PTX-008 with sunitinib in two colon cancer cell lines COLO205 and HT29 (which express low gal1, VEGFR and PDGFR mRNA), result in additive (CI=1) and synergistic (CI Conclusion. Combination of PTX-008 with sunitinib appears to be synergistic both in PTX-008-sensitive and -resistant cells, suggesting that modulation of gal1 signaling may be used to enhance the activity of sunitinib. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1548.

DD is the main toxicity of CPT-11 at the currently recommended dose (RD) of 350 mg/sqm IV (30’) q 3 weeks. In previously treated colorectal cancer patients (pts), we tried to determine the mechanism of DD and assess the efficacy of combined antidiarrheal medication. From Dec 93 until March 95, 24 pts having failed ≥ 1 ≤ 3 lines of 5-FU based treatment, entered a CPT-11 Phase II trial at the above RD. In the first cohort (14 pts), Acetorphan (Acet), a specific enkephalinase inhibitor, was given as 100 mg tid PO after the second loose stool, and supplemented, if DD > 48 hrs, with Loperamide (Lop) 2 mg q 2 hrs PO till 12 hrs after last loose stool. Pts had at baseline and if DD occurred endoscopy, with biopsies for Topo I and CPT-11 assays as well as transit time, stool frequency, weight, culture, electrolytes, osmotic gap, pH, fat and protein excretion, α antitrypsin ( α AT) clearance, D-xylose test; blood tests for VIP, glucagon, somatostatin, gastrin. Twelve/14 pts (first cohort) had CFT-11 DD: 5 responded to Acet alone, and the other 7 responded within 24 hrs to addition of Lop. Transit time normal in 5/7 pts, α AT increased in 4/4 pts. Stools weight >800 gr/day and fecal Na/K increased in 6/6 pts. Osmotic gap small in 3/6 pts. The second cohort (pts 15–25) received simultaneous Acet/Lop after first DD loose stool. Eight/11 pts had DD, and 7/8 had resolution of diarrhea within 12 hrs of treatment start. Available PK's of CPT-11 and SN-38 (active metabolite) show no pharmacodynamic relationship. Results suggest that CPT-11 DD is due to a secretory exudative mechanism, as attested by its response to early simultaneous antisecretory medications.

Current therapeutic modalities for childhood acute lymphoblastic leukemia (ALL) are associated with a high cure rate, and recurrences more than 4 years after therapy cessation are very unusual. We report three cases of exceptionally late recurrences of childhood ALL after cessation of chemotherapy (CT) given for respective periods of 8, 7, and 24 months. CT was followed by maintenance immunotherapy (IMT) with Bacillus Calmette-Guérin (BCG) and allogeneic leukemic lymphoblasts pretreated with formaldehyde or irradiated in vitro. Leukemic recurrences were observed 19, 11, and 9 years after cessation of CT and appeared morphologically similar to the original blasts. A second complete remission was easily achieved in all three patients, but two went on to repeated relapse (one has died following the fourth recurrence). We speculate that some residual leukemic cells, remaining after the inadequate, short-term CT, were responsible for these unusual evolutions, and we question a possible delaying role of IMT in prolonging remission. Other possible etiologies are discussed.

Rationale: BET-bromodomain (BRD) proteins play a major role in the epigenetic regulation of gene transcription, notably of genes with superenhancer promoter regions including many oncogenes, such as MYC. OTX015 is a specific BRD 2, 3 and 4 inhibitor that blocks oncogene transcription, and triggers growth inhibition and apoptosis in acute leukemia cell lines and patient cells in vitro (Braun et al. ASH Annual Meeting 2013). Based on these findings, a Phase 1 study of OTX015 was designed for patients with advanced acute leukemia. Patients & Methods: Patients with various unselected relapsed/refractory leukemia subtypes for which no standard therapy options were available were enrolled in this ongoing Phase 1 study. Patients aged < 60 years had to have failed at least two lines of therapy and those aged >60 years at least one line. At least 5% bone marrow leukemic blasts were required at study entry. OTX015 was given orally, daily for 14 days of 21-day cycles (cy). The dose was escalated from 10 to 160 mg daily (QD) according to a standard 3+3 dose-escalation design, to determine the maximum tolerated dose (MTD) or biologically optimal dose. A BID schedule was tested at dose level (DL) 4 (40 mg x 2) and a continuous schedule at 120 mg. Pharmacokinetics was studied on day 1 and residual concentrations were measured on days 2, 8 and 15. Responses were assessed on blood and bone marrow aspirations at baseline, days 8, 22 and 43. Blasts at baseline and day 8 were stored for pharmacodynamic biomarker evaluation. Cytogenetic and molecular markers were collected based on center practice. Results: From January 2013 to June 2014, 36 patients were treated over 6 dose levels: 33 with acute myeloid leukemia (AML), 2 with acute lymphoblastic leukemia and 1 with refractory anemia with excess blasts. Median age was 70 years (range 19-85), 20 patients were male, 29 patients had ECOG 0-1, and 16 AML patients had normal karyotype. Patients had a median of 2 prior therapy lines (range 1-4). The median number of OTX015 cycles administered was 2 (range 1-14+), including 9 patients with >3 cycles. Among the 28 patients evaluable for dose limiting toxicity (DLT), no DLTs were observed through DL5 (120 mg QD). The MTD was exceeded at DL6 (160 mg QD) with one patient experiencing grade 3 diarrhea and another grade 3 fatigue and anorexia. The main toxicities were non-cumulative grade 1-2 gastrointestinal events (6 patients diarrhea, 3 dysgueusia, 3 abdominal pain, 3 nausea, 1 anorexia), hyperglycemia (3 patients), coagulation factor VII decrease (6 patients) and direct bilirubin increase (3 patients) (two latter AEs asymptomatic). These toxicities were mainly observed at QD doses above 80 mg and with 40 mg BID. Dose proportional plasma concentrations were observed and trough concentrations > 500 nM (in vitro active concentrations) were regularly observed from 80 mg/day. Clinically relevant activity was reported in 5 AML patients treated at 10, 40 and 80 mg, including one sustained CR from cy 4 to cy 12 (40 mg QD) and one CR with incomplete platelet recovery (CRp) from cy 2 to cy 5 (80 mg QD). Two patients (10 mg QD, 40 mg QD) had partial blast clearance (disappearance of peripheral blasts and decrease >50% in bone marrow blast percentage) and the remaining patient (40 mg BID) had gum hypertrophy resolution. Four of these 5 patients had secondary or therapy-related AML, 4 had normal karyotype and 2 had an NPM1 gene mutation. Conclusions: OTX015 single agent exhibits antileukemic activity over a wide range of DLs and plasma concentrations in patients with advanced AML. MTD is exceeded at 160 mg QD. The safe recommended dose and schedule is close to being identified. Central extensive molecular marker analysis is being performed and will be prospectively implemented in an expansion cohort. Updated data will be presented and will include correlations between regimen, pharmacokinetics, clinical activity and molecular profile. Table Dose (Schedule) N pts evaluable Evidence of activity DLT 10 QD (14/21) 3 1 20 QD (14/21) 3 40 QD(14/21) 4 1 (CR) 80 QD(14/21) 3 2 (1 CRp) 40 BID (14/21) 6 1 120 QD (14/21) 3 120 QD (21/21) 3 160 QD (14/21) 3 Diarrhea (1) Anorexia/fatigue (1) Disclosures Dombret: Oncoethix SA: Research Funding. Preudhomme:Oncoethix SA: Research Funding. Berthon:Oncoethix SA: Research Funding. Raffoux:Oncoethix SA: Research Funding. Thomas:Oncoethix SA: Research Funding. Vey:Oncoethix SA: Research Funding. Gomez-Roca:Oncoethix SA: Research Funding. Ethell:Oncoethix SA: Research Funding. Yee:Oncoethix SA: Research Funding. Bourdel:Oncoethix SA: Employee of study CRO Other. Herait:Oncoethix SA: CMO and Shareholder Other. Michallet:Oncoethix SA: Research Funding. Recher:Oncoethix SA: Research Funding. Roumier:Oncoethix SA: Research Funding. Quesnel:Oncoethix SA: Research Funding.

A series of 21 patients (5 refractory anemias with an excess of blasts in transformation and 16 acute leukemias) were treated with small doses of ARA-C (10 mg/sq m/12 hr for 15–21 days). Improvement was noted in 15 cases (71%) and complete remission observed in 12 (57%). Complete remission was obtained after one course of treatment in 8 cases. The fact that these patients entered remission relatively slowly and did not suffer marrow aplasia suggests that low-dose ARA-C may function in vivo as it does in vitro, i.e., by inducing differentiation of leukemic blasts.