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Purpose: We determined the maximum tolerated dose (MTD), safety, pharmacokinetics, pharmacodynamics, and preliminary activity of OSI-906, a potent, oral, dual inhibitor of insulin-like growth factor-1 receptor (IGF1R) and insulin receptor (IR), in patients with advanced solid tumors. Experimental Design: This was a multicenter, open-label, dose escalation phase I study evaluating three intermittent dosing schedules of once-daily OSI-906 [schedule (S) 1, days 1–3 every 14 days; S2, days 1–5 every 14 days; S3, days 1–7 every 14 days]. A fed-fasting expansion cohort was included in the study. Results: Seventy-nine patients were enrolled: 62 in S1, 4 in S2, and 13 in S3. S2 was discontinued. Dose-limiting toxicity comprised grade 3–4 hyperglycemia, vomiting, fatigue, and prolonged QTc interval. The MTD and recommended phase II dose of OSI-906 was 600 mg for both S1 and S3 schedules. Other common adverse events were grade 1–2 nausea, vomiting, fatigue, and diarrhea. The pharmacokinetics of OSI-906 was dose linear, and the terminal half-life ranged between 2 and 6 hours. High-fat meals had a moderate effect on the pharmacokinetics of OSI-906. At the MTD, inhibition of IGF1R and IR was observed in peripheral blood mononuclear cells. An increase in plasma IGF1 concentrations, an indirect measure of IGF1R signaling inhibition, was seen at doses ≥ 450 mg. Two patients with adrenocortical carcinoma achieved partial responses. Conclusion: The MTD of 600 mg was well tolerated and associated with preliminary antitumor activity. These data support further evaluation of OSI-906 in solid tumors. Clin Cancer Res; 21(4); 693–700. ©2014 AACR. See related commentary by Yee, p. 667

Evidence that the phosphoinositide 3-kinase (PI3K) pathway is deregulated in ovarian cancer is largely based on the analysis of surgical specimens sampled at diagnosis and may not reflect the biology of advanced ovarian cancer. We aimed to investigate PI3K signaling in cancer cells isolated from patients with advanced ovarian cancer. Ascites samples were analyzed from 88 patients, of whom 61 received further treatment. Cancer cells were immunomagnetically separated from ascites, and the signaling output of the PI3K pathway was studied by quantifying p-AKT, p-p70S6K, and p-GSK3β by ELISA. Relevant oncogenes, such as PIK3CA and AKT, were sequenced by PCR-amplified mass spectroscopy detection methods. In addition, PIK3CA and AKT2 amplifications and PTEN deletions were analyzed by FISH. p-p70S6K levels were significantly higher in cells from 37 of 61 patients who did not respond to subsequent chemotherapy (0.7184 vs. 0.3496; P = 0.0100), and this difference was greater in patients who had not received previous chemotherapy. PIK3CA and AKT mutations were present in 5% and 0% of samples, respectively. Amplification of PIK3CA and AKT2 and deletion of PTEN was seen in 10%, 10%, and 27% of samples, respectively. Mutations of PIK3CA and amplification of PIK3CA/AKT2 or deletion of PTEN did not correlate with levels of p-AKT, p-p70S6K, and p-GSK3β. In patients with advanced ovarian cancer, there is an association between levels of p-p70S6K and response to subsequent chemotherapy. There is no clear evidence that this is driven specifically by PIK3CA or AKT mutations or by amplifications or deletion of PTEN. Mol Cancer Ther; 11(7); 1609–17. ©2012 AACR.

Platinum-based chemotherapy, with cytoreductive surgery, is the cornerstone of treatment of advanced ovarian cancer; however, acquired drug resistance is a major clinical obstacle. It has been proposed that subpopulations of tumor cells with stem cell–like properties, such as so-called side populations (SP) that overexpress ABC drug transporters, can sustain the growth of drug-resistant tumor cells, leading to tumor recurrence following chemotherapy. The histone methyltransferase EZH2 is a key component of the polycomb-repressive complex 2 required for maintenance of a stem cell state, and overexpression has been implicated in drug resistance and shorter survival of ovarian cancer patients. We observed higher percentage SP in ascites from patients that have relapsed following chemotherapy compared with chemonaive patients, consistent with selection for this subpopulation during platinum-based chemotherapy. Furthermore, ABCB1 (P-glycoprotein) and EZH2 are consistently overexpressed in SP compared with non-SP from patients' tumor cells. The siRNA knockdown of EZH2 leads to loss of SP in ovarian tumor models, reduced anchorage-independent growth, and reduced tumor growth in vivo. Together, these data support a key role for EZH2 in the maintenance of a drug-resistant, tumor-sustaining subpopulation of cells in ovarian cancers undergoing chemotherapy. As such, EZH2 is an important target for anticancer drug development. Mol Cancer Ther; 10(2); 325–35. ©2010 AACR.

Purpose of review Ovarian cancer remains the gynaecological malignancy with the highest mortality in the Western world. The strategy of identifying biologically distinct subgroups of ovarian cancer by means of clinical characteristics, histology and molecular profiling is an exciting prospect in personalizing and improving therapy for ovarian cancer. Recent findings Preclinical recognition that BRCA1 and BRCA2-associated tumours are very sensitive to inhibition of poly-ADP ribose polymerase (PARP), a key molecule in DNA repair, led to ovarian cancer patients with germline BRCA1 and BRCA2 mutations being treated with the PARP inhibitor olaparib (AZD2281, KU-0059436; KuDOS/Astra-Zeneca). The initial trials of olaparib in this patient population demonstrated an impressive rate of clinical benefit. Furthermore, tumours from patients with sporadic ovarian cancer have been found to commonly have somatic BRCA1 and BRCA2 mutations or other defects in DNA repair, with the implication that PARP inhibition may also have a role in treating these patients. Summary In this review, we discuss DNA repair mechanisms and strategies used to target them in oncology, our current experience with PARP inhibition in BRCA1 and BRCA2-mutation associated and sporadic ovarian cancer, as well as current issues in the clinical development of these agents.

Topotecan, a topoisomerase 1 inhibitor (topo1-i), is a semi-synthetic derivative of camptothecan with well-established cytotoxic properties. It is licensed for the treatment of relapsed, sensitive small cell lung cancer (SCLC) and for second line treatment in ovarian cancer. Studies have also shown this drug to be an effective first line treatment for SCLC with either cisplatin or in combination with a topoisomerase 2 inhibitor (topo2-i), etoposide; both combinations have shown similar efficacy. Oral and parenteral formulations of topotecan have proven to be equivocal in relapsed SCLC patients. The parenteral form showed reduced rates of severe haematological toxicities and better symptom control than an anthracycline combination (CAV). In relapsed SCLC, a randomised phase III trial of oral topotecan versus best supportive care showed a statistically significant increase in overall survival. In the second line treatment of non-small cell lung cancer (NSCLC), oral topotecan was not inferior to the current standard iv docetaxel for 1 year survival rates. Worthwhile potential investigations include combining oral topotecan with other oral agents to design treatments for different lines of therapy. The new oral formulation of topotecan also lends itself to testing with small molecule tyrosine kinase inhibitors. The myelosuppressive toxicity profile needs to be vigorously monitored and managed. The trials with oral topotecan have also highlighted the need to reassess the utility of the terms ‘sensitive’ and ‘resistant’ in the selection of patients with relapsed small cell lung cancer.

Hormone-driven expression of the ERG oncogene after fusion with TMPRSS2 occurs in 30% to 70% of therapy-naive prostate cancers. Its relevance in castration-resistant prostate cancer (CRPC) remains controversial as ERG is not expressed in some TMPRSS2-ERG androgen-independent xenograft models. However, unlike these models, CRPC patients have an increasing prostate-specific antigen, indicating active androgen receptor signaling. Here, we collected blood every month from 89 patients (54 chemotherapy-naive patients and 35 docetaxel-treated patients) treated in phase I/phase II clinical trials of an orally available, highly specific CYP17 inhibitor, abiraterone acetate, that ablates the synthesis of androgens and estrogens that drive TMPRSS2-ERG fusions. We isolated circulating tumor cells (CTC) by anti–epithelial cell adhesion molecule immunomagnetic selection followed by cytokeratin and CD45 immunofluorescence and 4′,6-diamidino-2-phenylindole staining. We used multicolor fluorescence in situ hybridization to show that CRPC CTCs, metastases, and prostate tissue invariably had the same ERG gene status as therapy-naive tumors (n = 31). We then used quantitative reverse transcription–PCR to show that ERG expression was maintained in CRPC. We also observed homogeneity in ERG gene rearrangement status in CTCs (n = 48) in contrast to significant heterogeneity of AR copy number gain and PTEN loss, suggesting that rearrangement of ERG may be an earlier event in prostate carcinogenesis. We finally report a significant association between ERG rearrangements in therapy-naive tumors, CRPCs, and CTCs and magnitude of prostate-specific antigen decline (P = 0.007) in CRPC patients treated with abiraterone acetate. These data confirm that CTCs are malignant in origin and indicate that hormone-regulated expression of ERG persists in CRPC. [Cancer Res 2009;69(7):2912–8]

Vascular endothelial growth factor (VEGF) is a key mediator of physiological and pathological angiogenesis. All solid tumors are dependent on pathological angiogenesis, and anti-VEGF therapy has demonstrated clinical benefit in breast, colorectal, non-small-cell lung, and renal carcinomas. Central nervous system metastases are common in many of these tumor types. An increased risk of bleeding has been reported with anti-VEGF therapy, but the risk of intracranial bleeding is unknown with this type of therapy. We reviewed the available data to investigate the risk of intracranial bleeding with anti-VEGF therapy in the presence and absence of CNS metastases. The PubMed and Medline databases and the Proceedings of the American Society of Clinical Oncology (ASCO) annual meetings were searched for articles, abstracts, and presentations of clinical trials. We identified 57 trials examining the safety and efficacy of anti-VEGF therapy in a total of 10,598 patients. Four trials examined the use of anti-VEGF therapy in treating patients with brain metastases. The presence of CNS metastases was a stated exclusion criterion in 76% of trials. The rate of intra cranial bleeding was negligible. We conclude that there is no trial evidence that anti-VEGF therapy confers an increased risk of intracranial bleeding, even in the presence of CNS metastases. Future trials of anti-VEGF therapy should not exclude patients with controlled CNS metastases at enrollment.

Purpose Clinical trials are critical to improving patient outcomes, but participation in cancer clinical trials is low. Patient understanding of clinical trial process is also limited. Patients are increasingly using the Internet as a source of information. It is critical that such Internet-based information is relevant, current, balanced, and easy to access and navigate. We critically reviewed seven international online resources that provide information for patients/consumers regarding cancer clinical trials. Methods Seven international websites from North America, Europe and Australia were selected based on profile/usage. Sites were evaluated with respect to their content, readability and appropriateness using a suite of standard assessment tools. Results No sites performed well in terms of all assessment criteria. There was substantial variation between sites regarding information provided, content, design and readability. All sites required high literacy levels and assessment using the Standard Assessment of Means tool showed consistent deficiencies. Conclusion Although there are numerous websites providing information about cancer clinical trials to patients/consumers, all evaluated sites have several shortcomings. Attention to the content of information, its presentation and the design of Internet resources has an ethical imperative, and is likely to lead to improved patient satisfaction.

Purpose: The vascular disrupting agent (VDA) combretastatin A4 phosphate (CA4P) induces significant tumor necrosis as a single agent. Preclinical models have shown that the addition of an anti-VEGF antibody to a VDA attenuates the revascularization of the surviving tumor rim and thus significantly increases antitumor activity. Experimental Design: Patients with advanced solid malignancies received CA4P at 45, 54, or 63 mg/m2 on day 1, day 8, and then every 14 days. Bevacizumab 10 mg/kg was given on day 8 and at subsequent cycles four hours after CA4P. Functional imaging with dynamic contrast enhanced-MRI (DCE-MRI) was conducted at baseline, after CA4P alone, and after cycle 1 CA4P + bevacizumab. Results: A total of 63 mg/m2 CA4P + 10 mg/kg bevacizumab q14 is the recommended phase II dose. A total of 15 patients were enrolled. Dose-limiting toxicities were grade III asymptomatic atrial fibrillation and grade IV liver hemorrhage in a patient with a history of hemorrhage. Most common toxicities were hypertension, headache, lymphopenia, pruritus, and pyrexia. Asymptomatic electrocardiographic changes were seen in five patients. Nine of 14 patients experienced disease stabilization. A patient with ovarian cancer had a CA125 response lasting for more than a year. DCE-MRI showed statistically significant reductions in tumor perfusion/vascular permeability, which reversed after CA4P alone but which were sustained following bevacizumab. Circulating CD34+ and CD133+ bone marrow progenitors increased following CA4P as did VEGF and granulocyte colony-stimulating factor levels. Conclusions: CA4P in combination with bevacizumab appears safe and well tolerated in this dosing schedule. CA4P induced profound vascular changes, which were maintained by the presence of bevacizumab. Clin Cancer Res; 18(12); 3428–39. ©2012 AACR.

Topotecan, a topoisomerase 1 inhibitor (topo1-i), is a semi-synthetic derivative of camptothecan with wellestablished cytotoxic properties. It is licensed for the treatment of relapsed, sensitive small cell lung cancer (SCLC) and for second line treatment in ovarian cancer. Studies have also shown this drug to be an effective first line treatment for SCLC with either cisplatin or in combination with a topoisomerase 2 inhibitor (topo2-i), etoposide; both combinations have shown similar efficacy. Oral and parenteral formulations of topotecan have proven to be equivocal in relapsed SCLC patients. The parenteral form showed reduced rates of severe haematological toxicities and better symptom control than an anthracycline combination (CAV). In relapsed SCLC, a randomised phase III trial of oral topotecan versus best supportive care showed a statistically significant increase in overall survival. In the second line treatment of non-small cell lung cancer (NSCLC), oral topotecan was not inferior to the current standard iv docetaxel for 1 year survival rates. Worthwhile potential investigations include combining oral topotecan with other oral agents to design treatments for different lines of therapy. The new oral formulation of topotecan also lends itself to testing with small molecule tyrosine kinase inhibitors. The myelosuppressive toxicity profile needs to be vigorously monitored and managed. The trials with oral topotecan have also highlighted the need to reassess the utility of the terms ‘sensitive’ and ‘resistant’ in the selection of patients with relapsed small cell lung cancer.

Poly(ADP-ribose) polymerase (PARP) is an attractive antitumor target because of its vital role in DNA repair. The homologous recombination (HR) DNA repair pathway is critical for the repair of DNA double-strand breaks and HR deficiency leads to a dependency on error-prone DNA repair mechanisms, with consequent genomic instability and oncogenesis. Tumor-specific HR defects may be exploited through a synthetic lethal approach for the application of anticancer therapeutics, including PARP inhibitors. This theory proposes that targeting genetically defective tumor cells with a specific molecular therapy that inhibits its synthetic lethal gene partner should result in selective tumor cell killing. The demonstration of single-agent antitumor activity and the wide therapeutic index of PARP inhibitors in BRCA1 and BRCA2 mutation carriers with advanced cancers provide strong evidence for the clinical application of this approach. Emerging data also indicate that PARP inhibitors may be effective in sporadic cancers bearing HR defects, supporting a substantially wider role for PARP inhibitors. Drugs targeting this enzyme are now in pivotal clinical trials in patients with sporadic cancers. In this article, the evidence supporting this antitumor synthetic lethal strategy with PARP inhibitors is reviewed, evolving resistance mechanisms and potential molecular predictive biomarker assays are discussed, and the future development of these agents is envisioned.

2516 Background: M-ICSOLs are often cited as an exclusion criteria in phase I trial protocols. This leads to patients with asymptomatic M-ICSOL being denied entry into phase I trials. We examined c...

Purpose Selective tumor cell cytotoxicity can be achieved through a synthetic lethal strategy using poly(ADP)-ribose polymerase (PARP) inhibitor therapy in BRCA1/2 mutation carriers in whom tumor cells have defective homologous recombination (HR) DNA repair. Platinum-based chemotherapy responses correlate with HR DNA repair capacity. Olaparib is a potent, oral PARP inhibitor that is well tolerated, with antitumor activity in BRCA1/2 mutation carriers. Patients and Methods Patients with BRCA1/2-mutated ovarian cancer were treated with olaparib within a dose-escalation and single-stage expansion of a phase I trial. Antitumor activity was subsequently correlated with platinum sensitivity. Results Fifty patients were treated: 48 had germline BRCA1/2 mutations; one had a BRCA2 germline sequence change of unknown significance, and another had a strong family history of BRCA1/2-associated cancers who declined mutation testing. Of the 50 patients, 13 had platinum-sensitive disease, 24 had platinum-resistant disease, and 13 had platinum-refractory disease (according to platinum-free interval). Twenty (40%; 95% CI, 26% to 55%) achieved Response Evaluation Criteria in Solid Tumors (RECIST) complete or partial responses and/or tumor marker (CA125) responses, and three (6.0%) maintained RECIST disease stabilization for more than 4 months, giving an overall clinical benefit rate of 46% (95% CI, 32% to 61%). Median response duration was 28 weeks. There was a significant association between the clinical benefit rate and platinum-free interval across the platinum-sensitive, resistant, and refractory subgroups (69%, 45%, and 23%, respectively). Post hoc analyses indicated associations between platinum sensitivity and extent of olaparib response (radiologic change, P = .001; CA125 change, P = .002). Conclusion Olaparib has antitumor activity in BRCA1/2 mutation ovarian cancer, which is associated with platinum sensitivity.

The development of anticancer drugs remains slow and costly. Use of predictive biomarkers has been postulated to not only accelerate this process but also increase the odds of drug approval ([1][1]). Despite concerns about the validation of the insulin-like growth factor receptor type I (IGF-IR) as

There is a growing body of evidence that although medical or surgical castration blocks the generation of gonadal testosterone in prostate cancer, androgens originating from other sources may continue to drive androgen receptor (AR) signaling. Recent studies have demonstrated high intratumoral levels of androgens and continued AR signaling in castration-resistant prostate cancer (CRPC), suggesting that androgens may also be synthesized de novo. Inhibiting the systemic biosynthesis of androgens in CRPC by targeting CYP17 may thus represent a rational therapeutic approach since this enzyme catalyses two key steroid reactions involving 17alpha-hydroxylase and C(17,20)-lyase in the androgen biosynthesis pathway. This review will discuss the rationale for and implications of targeting CYP17 in CRPC and focus on established and novel CYP17 inhibitors, including ketoconazole, abiraterone acetate, and VN/124-1, which are agents currently at different stages of development.

2530 Background: OSI-906 is a potent inhibitor of IGF-1R and IR tyrosine kinase activity. Increased IGF-1R activity is observed in human malignancies and implicated in resistance to chemotherapy. M...

5041 Background: A synthetic lethal approach by PARP inhibition has clinical activity in BDOC (NEJM 2009; 361: 123-34). Proposed mechanisms of PARPi resistance include the restoration of BRCA1/2 fu...

Background: AKT pathway activation is commonly described in ovarian cancer, and implicated in preclinical models of chemoresistance. Ascites occurs in a high proportion of patients at some stage in their illness. Purpose: To study the relationship between activation of the AKT pathway in human ovarian cancer ascites specimens (measured by the ratio of phosphorylated (P) to total (T) AKT pathway proteins) to patient survival and response to chemotherapy. In addition we studied the correlation of P/T AKT ratio to carboplatin sensitivity in a human ovarian cancer cell line panel. Method. 99 samples of ascites from 75 patients with ovarian cancer and a known treatment history were purified using anti-EpCam antibody coated magnetic beads (Dynal Biotech), stored at −80 degrees C, and then analysed with Mesoscale Discovery (MSD) ELISA for P/T AKT, GSK3β and p70S6K, and Pathscan ELISA for P/T 4EBP1 . Differences in survival in patient subgroups were analysed by logrank tests. Five cell lines (A2780, CH1, IGROV1, OVCAR3, SKOV3) were analysed in triplicate by sulphurhodamine B colorimetric assay to establish half maximal inhibitory concentration (IC50) for carboplatin and PI3K-AKT-mTOR pathway inhibitors (rapamycin, LY 294002, PI103, and Merck AKT inhibitor VIII), and the results correlated with baseline AKT pathway protein activation ratios. Results: Samples from patients who responded to chemotherapy (n=32) subsequent to sample collection had a lower median P/T S6K ratio (0.43) than those (n=28) who progressed (0.71, p=0.026, Mann-Whitney test; 39 samples were from patients who received no subsequent chemotherapy). Analysing the first sample for each patient, (n=75), those with a P/T AKT ratio above median (0.140) had a statistically significantly longer survival than those patients below median (28.0 months (m) vs 49.7 m, HR 1.74 (95% CI 1.01-3.01), p=0.048). A similar trend for P/T S6K ratio was also found, however this was not statistically significant (22.0 m vs 47.5 m, HR 1.56 (95%CI 0.90-2.71), p=0.112). In the ovarian cell line panel studied, a high P/T AKT ratio was found in the cells most resistant to carboplatin, whereas there was no relationship between AKT pathway activation and resistance to the AKT pathway inhibitors. Potential reasons for activation of the AKT pathway include amplification and mutation of PIK3CA and AKT2. Fluorescence in-situ hybridisation and sequencing of somatic DNA from these samples are ongoing. Conclusion: Patients who responded to subsequent chemotherapy had a significantly lower P/T S6K ratio than those who progressed. A P/T AKT ratio greater than 0.144 in malignant ascites predicts a statistically significant poorer prognosis. In vitro cell line models suggest a trend of P/T AKT ratio to correlate with carboplatin resistance. P/T AKT ratio should be studied prospectively as a prognostic and predictive biomarker in ovarian cancer. 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 788.

Background: OSI-906 is a potent small molecule inhibitor of the insulin-like growth factor 1 receptor (IGF-1R), a receptor tyrosine kinase that is overexpressed in several human cancer types and implicated in resistance to chemotherapy. Disruption of the growth hormone-IGF1 signaling axis can affect levels of biomarkers such as IGF1, growth hormone (GH) and insulin and can affect glucose homeostasis, making these potentially useful markers for demonstrating the activity of IGF-1R inhibitors in solid tissues. Methods: Two phase I dose escalation trials were initiated in cancer patients with advanced solid tumors who received OSI-906 on either continuous or intermittent dosing schedules. Pharmacodynamic (PD) and pharmacokinetic (PK) assessments were included as secondary objectives of these studies. Circulating biomarkers, including total IGF1, IGFBP3 and non-fasting GH and insulin levels, were measured at various times during the dosing cycle (21 days for continuous dosing; 14 days for intermittent dosing) and changes were correlated with plasma concentrations of OSI-906. Results: To date, patients have been treated with up to 450 mg QD and 200 mg BID on the continuous dosing schedule and up to 750 mg QD on the intermittent dosing schedule. Maximum tolerated dose (MTD) was determined to be 400 mg QD and 150 mg BID for continuous dosing and 600 mg QD for intermittent dosing. Preliminary analysis of the PK data suggests that the exposure of OSI-906 increased with dose. Median plasma concentrations of OSI-906 at MTD exceeded the predicted concentration required for efficacy based on the preclinical models (1 µM). Total IGF1 concentrations in plasma were increased relative to predose levels at doses ≥ 450 mg QD on the intermittent dosing schedule and ≥ 150 mg QD or 40 mg BID on the continuous dosing schedule. Elevations in non-fasting plasma insulin levels were also observed in patients with plasma concentrations of OSI-906 exceeding 5000 ng/mL. PK/PD relationships were observed for IGF1 and insulin. OSI-906 did not affect plasma IGFBP3 levels in most patients. Analysis of additional biomarkers, including GH, is ongoing. Conclusions: At or below MTD, plasma concentrations of OSI-906 could be achieved that exceed concentrations required for anti-tumor efficacy based on the preclinical models. The pharmacodynamic data indicate that pharmacologically-relevant concentrations of OSI-906 were achieved in tissues involved in regulating the GH-IGF1 signaling axis. Together, these PK and PD data indicate that the current recommended dosing regimens may provide sufficient exposure for activity against solid tumors. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A46.

3544 Background: IGF-1R is overexpressed in various malignancies, and implicated in proliferation, survival, and metastasis. IGF-1R blockade increases apoptosis and reduces tumor growth in preclinical models. OSI-906 is an oral small molecule tyrosine kinase IGR-1R inhibitor. Methods: Patients (pt) with advanced solid tumours were enrolled to determine safety, tolerability, maximum tolerated dose, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary anti-tumor activity. Results: 26 pt have been treated (14M:12F, median age 61 yrs) at 10, 20, 40, 80, 150, 300, and 450 mg on days (d) 1–3 q14 d. No dose-limiting toxicities have been observed to date. Drug-related toxicities include grade 1 fatigue, nausea, rash, diarrhea, tachycardia, proteinuria, pruritis and peripheral oedema. Linear PK was observed, with median terminal t1/2 3.5 hr; AUC0-∞ 25.8 μg.hr/mL; Cmax 3.20 μg/ml at 450mg. Plasma OSI-906 concentrations above the estimated efficacious concentration (1 μM) were attained at doses > 40mg. Glucose did not increase with rising OSI-906 concentration, but plasma insulin levels showed an upward trend, indicating potential PD effects. PD data on IGFR phosphorylation were analyzed. In total, 11 pt were treated for > 12 weeks (w). Of 3 pt with ACC, 1 pt had a partial response (43% reduction in primary and multiple lung metastases) and remains on treatment after 16 w, 1 pt was treated for 32 w, and 1 pt progressed after 4 w at 40mg. In addition, 1 pt with heavily pretreated NSCLC was treated for 43 w and 1 pt with progressive myxoid chondrosarcoma remains on treatment after 38 w. Conclusions: OSI 906 had minimal toxicity, dose proportional PK at dose levels up to 450mg tested d 1–3 q14 d, with preliminary antitumor activity seen, particularly in ACC. Dose escalation with 5 and 7 d schedules q14 d continues. [Table: see text]

5168 Background: Abiraterone acetate (A) is an oral compound with metabolites that selectively inhibit CYP 17(17OH/ 17,20 lyase), blocking adrenal androgen synthesis and exhibiting anti-tumor activity in castration resistant prostate cancer (CRPC). Methods: Patients were divided into fed or fasted groups, and treated at 1000mg/day as a single dose in either capsule or tablet formulation on day 1, then the opposite formulation one week later on day 8, and from day 15, continuous dosing of 1000mg of the tablet formulation. PK samples were taken pre-dose and 1, 2, 4, 6, 8, 24, 48 and 72 hr post dose on days 1 and 8. Statistical analysis employed a two- period crossover model, using non-compartmental analysis. Results: A was well tolerated and side effects readily managed by mineralocorticoid antagonists. Overall 31 patients were enrolled, with PK results from 19 patients presented here. Area under the curve (AUC), was not significantly different between the two formulations for either the fed (p=0.412) or th...

5072 Background: Recent studies have shown that CTCc predict OS in patients (pts) with CRPC. Methods: CTC were collected at baseline and after 1 and 2 cycles of treatment in CPRC pts starting a new...

5510 Background: AZD2281 is a novel, potent orally active PARP inhibitor. It induces cancer specific synthetic lethality in homologous recombination repair defective cells, including BRCA-deficient tumors. We previously reported a first-in-human Phase I trial, with dose escalation guided by toxicity, pharmacokinetic and pharmacodynamic (PD) data (Yap et al, ASCO 2007 Abstr 3529). Method: Initial dose escalation phase included patients (p) with a wide range of drug-resistant cancers. Once a PD active dose was identified, enrichment of the population with p with BRCA-deficient tumors was encouraged. Doses started from 10mg daily for 2 of 3 weeks, escalating to 600mg bd continuously. After the maximum tolerated dose (400mg bd) was identified, an expansion phase in BRCA-deficient ovarian cancer (BDOC) at 200mg bd was opened. Results: Of the total 92 p treated, 44 p had BDOC (includes 1 p with compelling family history). Doses received were 40mg daily (1 p), 100mg bd (3 p), 200mg bd (34 p), 400mg bd (5 p) and ...