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Figure S4. Landmark analysis (landmark point at 18 months) of OS (A, C) and PFS2 (B, D) in patients with multiple myeloma stratified according to ER18

Supplementary Appendix: • SUPPLEMENTARY METHODS. iFISH; ER24 analysis; clinical endpoints; statistical analysis; • SUPPLEMENTARY RESULTS. ER24 analysis; DS-ERMM score - additional analyses; outcome after relapse in the ER18 analysis; • TABLE S1A. Treatment regimens in the source studies; • TABLE S1B. Eligibility criteria for clinical trials; • TABLE S2. Patient characteristics in the overall population and stratified according to the ER24 outcome as training set and validation set; • TABLE S3. Univariate (UV) and multivariate (MV) analyses of the baseline features to predict ER24; LIST OF SUPPLEMENTARY FIGURE FILES.

Purpose:Despite the improvement of therapeutic regimens, several patients with multiple myeloma (MM) still experience early relapse (ER). This subset of patients currently represents an unmet medical need.Experimental Design:We pooled data from seven European multicenter phase II/III clinical trials enrolling 2,190 patients with newly diagnosed MM from 2003 to 2017. Baseline patient evaluation included 14 clinically relevant features. Patients with complete data (n = 1,218) were split into training (n = 844) and validation sets (n = 374). In the training set, a univariate analysis and a multivariate logistic regression model on ER within 18 months (ER18) were made. The most accurate model was selected on the validation set. We also developed a dynamic version of the score by including response to treatment.Results:The Simplified Early Relapse in Multiple Myeloma (S-ERMM) score was modeled on six features weighted by a score: 5 points for high lactate dehydrogenase or t(4;14); 3 for del17p, abnormal albumin, or bone marrow plasma cells >60%; and 2 for λ free light chain. The S-ERMM identified three patient groups with different risks of ER18: Intermediate (Int) versus Low (OR = 2.39, P < 0.001) and High versus Low (OR = 5.59, P < 0.001). S-ERMM High/Int patients had significantly shorter overall survival (High vs. Low: HR = 3.24, P < 0.001; Int vs. Low: HR = 1.86, P < 0.001) and progression-free survival-2 (High vs. Low: HR = 2.89, P < 0.001; Int vs. Low: HR = 1.76, P < 0.001) than S-ERMM Low. The Dynamic S-ERMM (DS-ERMM) modulated the prognostic power of the S-ERMM.Conclusions:On the basis of simple, widely available baseline features, the S-ERMM and DS-ERMM properly identified patients with different risks of ER and survival outcomes.

The treatment landscape for relapsed multiple myeloma has expanded considerably in recent years, as numerous agents with new mechanisms of action have been introduced, increasing responses even in advanced disease and prolonging survival. The wealth of novel regimens comes with the challenges of balancing toxicities and aligning a regimen with the biology of the myeloma and the nature of the relapse in conjunction with patient treatment history and personal preference. Herein, we provide an overview of treatment options for both early and late relapsing disease as well as a discussion of the role of emerging immune-based therapies.

Over the last decade, the development of effective treatment approaches for multiple myeloma (MM) has been associated with higher response rates and longer survival. In patients who achieve complete response, several high sensitivity techniques have been studied to assess minimal residual disease (MRD) and detect residual neoplastic cells within the bone marrow (by flow cytometry or molecular biology techniques) or outside the bone marrow (by imaging or circulating disease markers in the peripheral blood). This is of utmost importance, since residual disease can drive clinical relapse. This review focuses on the progress made in the assessment of MRD in MM. The achievement of MRD negativity after therapy is considered prognostically important for MM patients, and data from clinical trials and meta-analyses have confirmed that it is strongly associated with better survival. Along with well-known techniques, such as next-generation sequencing (NGS), next-generation flow (NGF), and positron emission tomography/computed tomography (PET/CT), other methods such as mass spectrometry (MS) and circulating tumor cells are under study. Intensive treatment regimens at diagnosis can lead up to 70% of MRD negativity in MM patients, although the current proportion of curable patients is still unknown. Today, clinicians who treat MM deal with MRD assessment in routine clinical practice. Its appropriate use in therapeutic decision making may be the most fascinating and challenging issue to be addressed over the next few years.

PURPOSE High levels of circulating tumor plasma cells (CTC-high) in patients with multiple myeloma are a marker of aggressive disease. We aimed to confirm the prognostic impact and identify a possible cutoff value of CTC-high for the prediction of progression-free survival (PFS) and overall survival (OS), in the context of concomitant risk features and minimal residual disease (MRD) achievement. METHODS CTC were analyzed at diagnosis with two-tube single-platform flow cytometry (sensitivity 4 × 10–5) in patients enrolled in the multicenter randomized FORTE clinical trial (ClinicalTrials.gov identifier: NCT02203643 ). MRD was assessed by second-generation multiparameter flow cytometry (sensitivity 10–5). We tested different cutoff values in series of multivariate (MV) Cox proportional hazards regression analyses on PFS outcome and selected the value that maximized the Harrell's C-statistic. We analyzed the impact of CTC on PFS and OS in a MV analysis including baseline features and MRD negativity. RESULTS CTC analysis was performed in 401 patients; the median follow-up was 50 months (interquartile range, 45-54 months). There was a modest correlation between the percentage of CTC and bone marrow plasma cells ( r = 0.38). We identified an optimal CTC cutoff of 0.07% (approximately 5 cells/µL, C-index 0.64). In MV analysis, CTC-high versus CTC-low patients had significantly shorter PFS (hazard ratio, 2.61; 95% CI, 1.49 to 2.97, P < .001; 4-year PFS 38% v 69%) and OS (hazard ratio, 2.61; 95% CI, 1.49 to 4.56; P < .001; 4-year OS 68% v 92%). The CTC levels, but not the bone marrow plasma cell levels, affected the outcome. The only factor that reduced the negative impact of CTC-high was the achievement of MRD negativity (interaction P = .039). CONCLUSION In multiple myeloma, increasing levels of CTC above an optimal cutoff represent an easy-to-assess, robust, and independent high-risk factor. The achievement of MRD negativity is the most important factor that modulates their negative prognostic impact.

The current strategies for the treatment of multiple myeloma (MM) have improved, thanks to effective drug classes and combination therapies, for both the upfront and relapsed settings. Clinical trials for newly diagnosed transplant-ineligible patients led to the approval of immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) in combination with anti-CD38 monoclonal antibodies (mAbs), to be administered during the induction phase before transplantation and during maintenance treatment, with lenalidomide recommended until relapse. In relapsed/refractory patients, the complex treatment scenario currently includes several options, such as triplets with anti-CD38 mAbs plus IMiDs or PIs, and novel targeted molecules. Comparisons among clinical trials and real-world data showed a good degree of reproducibility of some important results, particularly in terms of overall response rate, progression-free survival, and overall survival. This may help clinicians towards a proper selection of the best treatment options, particularly in real-world settings. However, as compared with the management of real-world settings, clinical trials have some pitfalls in terms of outcome and especially in terms of safety and quality of life. In fact, trials include younger and presumably healthier patients, excluding those with worst clinical conditions due to MM features (e.g., renal insufficiency or bone disease, which can impair the performance status) and comorbidities (e.g., cardiac and pulmonary disease), thus resulting in a possible lack of representativeness of data about the patients enrolled. In this review, we analyze comparable and discrepant results from clinical trials vs. real-world settings published in the last 10 years, focusing on different drugs and combinations for the treatment of MM and providing an overview of treatment choices.

Background: Bortezomib-based induction followed by high-dose melphalan (200 mg/m2) and autologous stem-cell transplantation (MEL200-ASCT) and maintenance treatment with lenalidomide alone is the current standard of care for young and fit patients with newly diagnosed multiple myeloma. We aimed to evaluate the efficacy and safety of different carfilzomib-based induction and consolidation approaches with or without transplantation and of maintenance treatment with carfilzomib plus lenalidomide versus lenalidomide alone in newly diagnosed multiple myeloma. Methods: UNITO-MM-01/FORTE was a randomised, open-label, phase 2 trial done in 42 Italian academic and community practice centres. We enrolled transplant-eligible patients with newly diagnosed multiple myeloma aged 65 years or younger with a Karnofsky Performance Status of 60% or higher. Patients were stratified according to International Staging System stage (I vs II/III) and age (

Background. Proteasome inhibitor (PI)-based induction/consolidation proved to be effective in newly diagnosed multiple myeloma (NDMM) patients (pts) eligible for melphalan 200 mg/m2 plus autologous stem-cell transplantation (MEL200-ASCT). High response rates have been reported with carfilzomib (K) plus lenalidomide-dexamethasone (KRd) or cyclophosphamide-dexamethasone (KCd). Lenalidomide (R) alone is a standard of care for post-ASCT maintenance; K maintenance showed promising results in phase I/II studies, but no data on KR maintenance vs R are available. Aims. The aims of this analysis were to evaluate the progression-free survival (PFS) of KRd induction-ASCT-KRd consolidation (KRd_ASCT) vs 12 cycles of KRd (KRd12) vs KCd induction-ASCT-KCd consolidation (KCd_ASCT) and the PFS of KR vs R maintenance. Secondary aims were efficacy in different subgroups of pts and safety of the maintenance phase. Methods. NDMM pts ≤65 years were randomized [R1: 1:1:1, stratification International Staging System (ISS) and age] to: KRd_ASCT: 4 28-day cycles with KRd induction (K 20/36 mg/m2 IV days 1,2,8,9,15,16; R 25 mg days 1-21; dexamethasone [d] 20 mg days 1,2,8,9,15,16) followed by MEL200-ASCT and 4 KRd consolidation cycles; KRd12: 12 KRd cycles; KCd_ASCT: 4 28-day induction cycles with KCd (K 20/36 mg/m2 IV days 1,2,8,9,15,16; cyclophosphamide 300 mg/m2 days 1,8,15; d 20 mg days 1,2,8,9,15,16) followed by MEL200-ASCT and 4 KCd consolidation cycles. Thereafter, pts were randomized (R2) to maintenance with KR (K 36 mg/m2 days 1,2,15,16, subsequently amended to 70 mg/m2 days 1,15 for up to 2 years; plus R 10 mg days 1-21 every 28 days until progression) or R alone (10 mg days 1-21 every 28 days until progression). Centralized minimal residual disease (MRD) evaluation (8-color second-generation flow cytometry, sensitivity 10-5) was performed in pts achieving ≥very good partial response before maintenance and every 6 months (m) during maintenance. Data cut-off was June 30, 2020. Results. 474 NDMM pts were randomized (KRd_ASCT, n=158; KRd12, n=157; KCd_ASCT, n=159) and analyzed. Pt characteristics were well balanced. Intention-to-treat (ITT) data of pre-maintenance MRD (KRd_ASCT, 62%; KRd12 56%, KCd_ASCT 43%) and safety of the induction/consolidation phases in the 3 arms were already reported (F. Gay et al. ASH 2018; S. Oliva et al. ASH 2019). After a median follow-up from R1 of 45 m, median PFS was not reached with KRd_ASCT, 57 m with KRd12 and 53 m with KCd_ASCT (KRd_ASCT vs KCd_ASCT: HR 0.53, P During maintenance, a similar proportion of pts experienced ≥1 grade (G)3-4 hematologic adverse events (AEs)/serious AEs (SAEs) in the 2 arms (KR 22% vs R 23%); the most frequent were neutropenia (KR 18% vs R 21%) and thrombocytopenia (KR 3% vs R 3%). Rate of ≥1 G3-4 non-hematologic AEs/SAEs was higher with KR (27%) compared with R (15%), P=0.012; the most frequent were infections (KR 4% vs R 7%); all other events were reported in ≤5% of pts and included: gastrointestinal (KR 5% vs R 2%), cardiac (KR 4% vs R 1%), hypertension (KR 3% vs R 0%), and thrombotic microangiopathy (3% vs 0%). 4 pts developed a second primary malignancy in KR (breast 1 pt; thyroid 1 pt; myelodysplastic syndrome 1 pt; non-melanoma skin cancer 1pt) vs 1 pt in R (acute lymphoblastic leukemia). Dose reductions of R were reported in 23% of KR and 29% of R pts; dose reductions of K were reported in 20% of pts. The rate of discontinuation due to AEs was similar in the 2 arms (KR 10% vs R 9%). Conclusions. Treatment with KRd_ASCT significantly improved PFS compared with both KRd12 and KCd_ASCT. Maintenance with KR also improved PFS vs R. Figure Disclosures Gay: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Musto:Celgene: Honoraria; Amgen: Honoraria. Galli:BMS: Honoraria; Celgene: Honoraria; Janssen: Honoraria; Takeda: Honoraria. Belotti:Jannsen: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Zamagni:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Speakers Bureau; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Speakers Bureau; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Speakers Bureau. Zambello:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. De Sabbata:Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. D'Agostino:GSK: Membership on an entity's Board of Directors or advisory committees. Liberati:VERASTEM: Honoraria, Research Funding; ROCHE: Honoraria, Research Funding; PFIZER: Honoraria, Research Funding; ONCOPEPTIDES AB: Honoraria, Research Funding; TAKEDA: Honoraria, Research Funding; MORPHOSYS: Honoraria, Research Funding; ONCONOVA: Honoraria, Research Funding; ABBVIE: Honoraria, Research Funding; NOVARTIS: Honoraria, Research Funding; KARYOPHARM: Honoraria, Research Funding; INCYTE: Honoraria; JANSSEN: Honoraria; CELGENE: Honoraria; AMGEN: Honoraria; BMS: Honoraria; BEIGENE: Honoraria; ARCHIGEN: Honoraria; BIOPHARMA: Honoraria; FIBROGEN: Honoraria. Offidani:Janssen: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Cavo:AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Speakers Bureau; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau. Boccadoro:AbbVie: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Research Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Research Funding; Amgen: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding. OffLabel Disclosure: The presentation includes discussion of off-label use of a drug or drugs for the treatment of multiple myeloma (including carfilzomib, cyclophosphamide, lenalidomide and dexamethasone).

The introduction of novel agents, characterized by favorable toxicity profiles and higher manageability compared to conventional drugs employed in the past, has considerably changed the treatment paradigm for multiple myeloma. Continuous therapy currently represents the standard approach for myeloma patients both at diagnosis and at relapse. In younger patients, long-term maintenance after autologous transplantation significantly improved progression-free survival and overall survival compared to observation. Also in transplant-ineligible patients, continuous treatment with combinations of newer agents and maintenance treatment following a more intense induction phase proved to be superior as compared to fixed-duration therapy. Maintenance and continuous therapy at diagnosis have shown to deepen responses and suppress minimal residual disease. At relapse, continuous therapy allowed better disease control over time. This review covers the main evidence supporting the use of continuous therapy in multiple myeloma as well as the open issues, such as the optimal agents to be used and the optimal candidates for receiving them.

Purpose: Despite the improvement of therapeutic regimens, several patients with multiple myeloma (MM) still experience early relapse (ER). This subset of patients currently represents an unmet medical need. Experimental Design: We pooled data from seven European multicenter phase II/III clinical trials enrolling 2,190 patients with newly diagnosed MM from 2003 to 2017. Baseline patient evaluation included 14 clinically relevant features. Patients with complete data (n = 1,218) were split into training (n = 844) and validation sets (n = 374). In the training set, a univariate analysis and a multivariate logistic regression model on ER within 18 months (ER18) were made. The most accurate model was selected on the validation set. We also developed a dynamic version of the score by including response to treatment. Results: The Simplified Early Relapse in Multiple Myeloma (S-ERMM) score was modeled on six features weighted by a score: 5 points for high lactate dehydrogenase or t(4;14); 3 for del17p, abnormal albumin, or bone marrow plasma cells >60%; and 2 for λ free light chain. The S-ERMM identified three patient groups with different risks of ER18: Intermediate (Int) versus Low (OR = 2.39, P < 0.001) and High versus Low (OR = 5.59, P < 0.001). S-ERMM High/Int patients had significantly shorter overall survival (High vs. Low: HR = 3.24, P < 0.001; Int vs. Low: HR = 1.86, P < 0.001) and progression-free survival-2 (High vs. Low: HR = 2.89, P < 0.001; Int vs. Low: HR = 1.76, P < 0.001) than S-ERMM Low. The Dynamic S-ERMM (DS-ERMM) modulated the prognostic power of the S-ERMM. Conclusions: On the basis of simple, widely available baseline features, the S-ERMM and DS-ERMM properly identified patients with different risks of ER and survival outcomes.

Extreme longevity is the paradigm of healthy aging as individuals who reached the extreme decades of human life avoided or largely postponed all major age-related diseases. In this study, we sequenced at high coverage (90X) the whole genome of 81 semi-supercentenarians and supercentenarians [105+/110+] (mean age: 106.6 ± 1.6) and of 36 healthy unrelated geographically matched controls (mean age 68.0 ± 5.9) recruited in Italy. The results showed that 105+/110+ are characterized by a peculiar genetic background associated with efficient DNA repair mechanisms, as evidenced by both germline data (common and rare variants) and somatic mutations patterns (lower mutation load if compared to younger healthy controls). Results were replicated in a second independent cohort of 333 Italian centenarians and 358 geographically matched controls. The genetics of 105+/110+ identified DNA repair and clonal haematopoiesis as crucial players for healthy aging and for the protection from cardiovascular events.

Relapsed or refractory (R/R) acute myeloid leukemia (AML) has a poor prognosis, and new therapies are a major clinical need. When mutated, FLT3 drives neoplastic cell proliferation. New drugs (i.e., tyrosine kinase inhibitors, TKIs) showed effectiveness in FLT3-AML and promise to change disease history and outcome. We evaluated the benefit conferred by TKIs in terms of survival, burden of complications and surrogate endpoint of quality of life in a retrospective cohort of 49 FLT3 positive, R/R AML patients. Patients who received TKIs were compared to those treated with conventional chemotherapy. Treatment with TKIs conferred a better OS and wea associated with a lower burden and severity of adverse events. Importantly, patients who received TKIs showed reduced time of hospitalization. In conclusion, treatment with TKI in R/R FLT3-AML was related to a better survival, less and milder AEs, and shorter hospitalization.

Background Despite an improvement in treatment response, high-risk multiple myeloma (MM) patients (pts) experience early relapse and short disease-free survival. Together with more validated high-risk features, high levels of circulating plasma cells (high CPC) have been considered a marker of aggressive disease and poor outcome (F. Gay et al, ASH 2019; W.I. Gonsalves et al, Am J Hematol 2020). To date, there are no uniform data on the optimal cut-off predictive of clinical outcome. No prospective data on CPC are available in the setting of novel-drug clinical trials with comprehensive baseline evaluation and minimal residual disease (MRD) assessment. Aims 1) To identify the best cut-off for CPC to predict progression-free survival (PFS); 2) to assess the impact of high CPC levels on the clinical outcome of newly diagnosed (ND)MM pts in the context of concomitant risk features and MRD evaluation. Methods In the multicenter randomized FORTE clinical trial, 474 NDMM pts ≤65 years were randomized (R1) to receive either: carfilzomib-lenalidomide-dexamethasone (KRd) induction-autologous stem-cell transplant-KRd consolidation (KRd_ASCT); KRd for 12 cycles (KRd12); or carfilzomib-cyclophosphamide-dexamethasone (KCd) induction-ASCT-KCd consolidation (KCd_ASCT). Thereafter, pts were randomized (R2) to maintenance treatment with lenalidomide alone (R) or plus carfilzomib (KR). MRD was assessed by 2nd-generation multiparameter flow cytometry (MFC, sensitivity 10-5) in pts who achieved ≥very good partial response before maintenance and then every 6 months. At diagnosis, single-platform FC was used to sort and count CPC. Receiver Operating Characteristic (ROC) analysis was used to define a cut-off based on PFS at 36 months as outcome. Correlations between high CPC and the most important baseline prognostic features (age, International Staging System (ISS), lactate dehydrogenase (LDH), chromosomal abnormalities (CA) by FISH [(del17p, t(4;14), t(14;16), t(11;14), amp1q, del1p, del13], Revised-ISS (R-ISS)) were explored. Hence, we performed a multivariate (MV) analysis to assess the impact of high CPC on the achievement of MRD negativity, on PFS and OS. Finally, we evaluated the impact of baseline CPC and MRD achievement. Results CPC analysis was performed in 401/474 pts at diagnosis; median follow-up was 44.2 months (39.6-47.9) and baseline features were similar to those reported in the overall FORTE population. Median CPC were 0.02% (IQR 0-0.14). The optimal CPC cut-off to predict PFS (ROC analysis) was 0.07% (5 cells/ul, 0.005 x109/l) and was consistent with a cut-off previously identified as a predictor of sustained MRD negativity (MRDsus12; L. Bertamini et al, EHA 2020). High-CPC pts (>0.07%) were 130/401 (32%), while 271/401 (68%) had low CPC (≤0.07%). The proportion of high-CPC pts was comparable among treatment arms. Baseline features significantly associated with high CPC in a MV analysis were: ISS II/III, high LDH, amp1q, t(4;14), t(14;16) and bone marrow plasma cells (>60%). Regarding PFS, in a MV analysis adjusted for R-ISS and R1 treatment, including all the baseline features, high CPC were associated with a lower PFS (HR 2.49, 95% CI 1.76-3.51, P The impact of baseline CPC levels on PFS was consistent in all high-risk subgroups (Fig. 1C), except in those patients who achieved pre-maintenance MRD negativity [(neg); interaction P=0.03]. Low-CPC and MRD-neg pts showed the best outcome with a 3-year PFS of 84%. Low-CPC MRD-positive (pos) and high-CPC MRD-neg pts had similar 3-year PFS (70% vs 68%). High-CPC MRD-pos pts had a dismal outcome (3-year PFS 32%; Fig. 1D). Conclusion High CPC with a cut-off of 0.07% (5 cells/ul, 0.005 x109/l) is a strong and independent high-risk factor, predicting a shorter PFS and OS even in the context of other high-risk features. The achievement of MRD neg independently improved the poor prognosis of high-CPC patients. Figure 1 Disclosures D'Agostino: GSK: Membership on an entity's Board of Directors or advisory committees. Galieni:Janssen: Honoraria; AbbVie: Honoraria; Takeda: Honoraria; Celgene: Honoraria. Molica:Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Tacchetti:Oncopeptides: Honoraria; AbbVie: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Janssen: Honoraria. Musto:Amgen: Honoraria; Celgene: Honoraria. Gay:GSK: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Boccadoro:GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; AbbVie: Honoraria; Mundipharma: Research Funding. Oliva:Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Takeda: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: The presentation includes discussion of off-label use of a drug or drugs for the treatment of multiple myeloma (including carfilzomib, cyclophosphamide, lenalidomide and dexamethasone).

Multiple myeloma (MM) is still considered an incurable hematologic cancer and, in the last decades, the treatment goal has been to obtain a long-lasting disease control. However, the recent availability of new effective drugs has led to unprecedented high-quality responses and prolonged progression-free survival and overall survival. The improvement of response rates has prompted the development of new, very sensitive methods to measure residual disease, even when monoclonal components become undetectable in patients’ serum and urine. Several scientific efforts have been made to develop reliable and validated techniques to measure minimal residual disease (MRD), both within and outside the bone marrow. With the newest multidrug combinations, a good proportion of MM patients can achieve MRD negativity. Long-lasting MRD negativity may prove to be a marker of “operational cure”, although the follow-up of the currently ongoing studies is still too short to draw conclusions. In this article, we focus on results obtained with new-generation multidrug combinations in the treatment of high-risk smoldering MM and newly diagnosed MM, including the potential role of MRD and MRD-driven treatment strategies in clinical trials, in order to optimize and individualize treatment.

Background. High rates of response and minimal residual disease (MRD) negativity have been reported with the use of novel treatment options in multiple myeloma (MM) patients (pts) eligible for autologous stem-cell transplantation (ASCT). Despite very promising results, there is still a proportion of pts who do not respond to therapy or relapse early. This represents an unmet medical need. Aim. To identify the main factors predictive of early relapse in the context of novel treatment approaches. Methods. Data from newly diagnosed MM (NDMM) pts ≤65 years enrolled in the FORTE trial were analyzed. The evaluated baseline standard clinical and biological features included: age, Hb, creatinine, tumor circulating plasma cells (PCpb) evaluated by flow cytometry, bone marrow plasma cells (PCbm) evaluated as continuous variables, free light chain (L vs K), M-component subtype (IgA vs others), Revised International Staging System (R-ISS II/III vs I), LDH (>ULN vs ≤ULN), ISS (III vs II vs I), presence vs absence of chromosomal abnormalities detected by FISH [(del17p, t(4;14), t(14;16), t(11;14), amp1q, del1p, del13], and presence vs absence of plasmacytomas. Pts were randomized to receive carfilzomib, lenalidomide, dexamethasone (KRd) induction - ASCT intensification - KRd consolidation (arm A); KRd12 (arm B); and carfilzomib, cyclophosphamide, dexamethasone (KCd) induction - ASCT intensification - KCd consolidation (arm C). Thereafter, patients were randomized to maintenance with lenalidomide alone or lenalidomide plus carfilzomib. Pre-maintenance MRD evaluation was performed by 8-color second generation flow cytometry (sensitivity 10-5) in patients who achieved at least a very good partial response (VGPR). Early relapse was defined as relapse ≤18 months from randomization. Univariate feature selection was performed between both categorical and continuous baseline variables and the achievement of pre-maintenance MRD negativity, according to Chi-square and Kruskal tests. The same baseline features, plus the achievement of MRD negativity, were included in a univariate analysis to select candidate predictors of early relapse. Selected features were then included in a multivariate logistic model. A multivariate analysis was performed to evaluate predictors of MRD negativity and early relapse. The model was adjusted for age and administered therapy. Results. 474 patients were enrolled in the trial. Baseline features were well balanced in the 3 arms. Predictors of MRD negativity (10-5): In univariate analysis, the baseline factors selected basing on the probability of achieving pre-maintenance MRD negativity were creatinine levels, ISS stage, R-ISS stage, del17p, PCbm (P=0.004) and PCpb. In multivariate analysis, including single variables not aggregated in R-ISS, increased creatinine levels (OR 0.48, 95% CI 0.25-0.94, P=0.03), increased PCbm (OR 0.95, 95% CI 0.91-0.99, P=0.01) and presence of del17p (OR 0.44, 95% CI 0.23-0.83, P=0.01) reduced the probability of achieving MRD negativity (Table). Predictors of early relapse: In univariate analysis, the main baseline factors selected basing on the risk of early relapse were LDH, ISS, R-ISS, PCbm, PCpb, del17p and achievement of MRD negativity. In multivariate analysis, R-ISS II/III vs I (OR 3.7, 95% CI 1.24-11, P Discussion. In the context of novel highly effective treatment approaches, creatinine levels, PCbm and, in particular, presence of del17p reduced the probability of achieving MRD negativity. Multivariate analysis combining baseline features and MRD negativity highlights how comprehensive baseline evaluation including baseline R-ISS (or in particular high LDH levels, which may have an independent role) and circulating PC can help to identify patients at high risk of early relapse. However, the achievement of MRD negativity is the factor that may reduce the risk of early relapse. Disclosures Gay: Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Offidani:Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vozella:Celgene: Honoraria; Amgen: Honoraria. Belotti:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Galli:Takeda: Honoraria; Leadiant (Sigma-Tau): Honoraria; Janssen: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria. Gozzetti:Celgene: Honoraria; Amgen: Honoraria; Jansenn: Honoraria; BMS: Honoraria. Giuliani:Janssen: Research Funding. Musto:Amgen: Honoraria; Celgene: Honoraria. Cavo:sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Boccadoro:Sanofi: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; AbbVie: Honoraria; Mundipharma: Research Funding. OffLabel Disclosure: The presentation includes discussion of off-label use of a drug or drugs for the treatment of multiple myeloma.

Introduction Monosomy 7 (-7) and interstitial deletions of chromosome 7 (7q-) are among the most recurrent chromosomal aberrations found in myeloid neoplasms. Patients carrying these cytogenetical alterations present a poor overall survival (OS), mainly due to a low sensitivity to standard chemotherapy and a high incidence of relapse. In our study, we aimed to disentangle the biology of patients with -7/7q- and find new candidate therapeutic targets for a disease with such a dismal prognosis, by integrating wide genomic approaches. Methods We collected bone marrow samples from 487 adult patients at diagnosis, treated in 3 institutions: Institute L. & A. Seragnoli (Italy, n = 213), CEMM (Austria, n = 160), University of Michigan (US, n = 114, GSE23452). Three hundred ninety-five samples were analyzed by SNP arrays (Affymetrix™), 51 samples by mass spectrometry (Metabolon™) and 57 samples by GEP (Affymetrix™) approaches. Chi-squared, fisher's exact test and ANOVA were used to test differences in proportion and distributions. False discovery rate, Bonferroni correction, and Welch's correction were calculated whenever appropriate. Results Among the 474 patients with evaluable karyotype, 65 (13.7%) had -7/7q-; 47 (9.9%) had -7, while 18 (3.8%) had 7q-. In our sets, the median age at AML diagnosis was 64 years (21-86) and most of the subjects had a de novo AML (65.1%). WBC count at diagnosis was significantly lower in -7/7q- patients (10.4 vs 35.2 k/mm3 p Within patients tested for FLT3, NPM1 and TP53 mutation at diagnosis, 1/50 among -7/7q- patients vs 59/300 controls harbored FLT3 ITD mutation (350 patients tested, 2% vs 19.7%, p In terms of outcome, -7/7q- AML had a median of overall survival of 10.3 months (95% C.I 5.8-14.8), which accounted for 49.5 months (95% C.I. 40.5-58.4) in other AML cases. GEP data of a cohort of 57 patients (8 with -7/7q- and 49 controls) revealed that 24 genes were under-expressed in -7/7q- AML (with e-4 significance threshold, Figure 1A). Twenty-three out of 24 genes mapped on chromosome 7; one gene, COX17, mapped on chromosome 3 (Figure 1A). COX17 plays a role in the recruitment of copper to mitochondria. By metabolomic analyses, we considered quantitative data of 300 different metabolites in 32 patients (4 with -7/7q- vs 28 controls, 19 patients were excluded because samples at diagnosis were not available). In -7/7q- AML, fatty acids (sphingomyelin, 1-linoleoylglycerol), β-cytrilglutamate and the UDP were overrepresented if compared with other AML cases; on the other hand, galactiol and 1-(1-enyl-palmitoyl)-2-linoleoyl-GPC were underrepresented in -7/7q- patients. Furthermore, -7/7q- AML cells seem to accumulate 3-hydroxy-3-methylglutarate and to have lower levels of 2-Hydroxyglutarate (Figure 1C). With SNP arrays, we considered copy number alterations in 395 patients (52 -7/7q- patients vs 343 controls, Figure 1B). 5q was the most recurrent concurrent deletion, with a minimal common deleted region (MCDR) in q31.3-q33.3. Additionally, 17p (MCDR p11.2 - p13.1), 12p (MCDR p12.3-p13.1), 16q (MCDRs q11.2-q12.1, q21-q22.1 and q24.2-q24.3), 16p (MCDR p11.2) and chromosome 4 (MCDRs q34.1 and q35.2) deletions also co-occurred in -7/7q-, listed per frequencies (Figure 1B). These regions are enriched for genes controlling cell signaling, DNA transcription, post-transcriptional modifications (such as SUMOylation), mRNA splicing and cellular senescence. Conclusions SNP, GEP and metabolomic approaches gave new insights on -7/7q- AML biology, identifying 24 new genes differentially expressed in -7/7q-, and 6 MCDR associated with -7/7q- AML. Deletion of chromosome 16q and 4 were never reported in literature associated to AML. Furthermore, for the first time, we described metabolites associated with -7/7q- AML. These data may represent a useful backbone to search for candidate targets in the setting of one of the most aggressive AML subtypes. Supported by:EHA Non-Clinical Junior Research Fellowship,HARMONY,Fondazione del Monte,FP7-NGS-PTL,AIRC. *MCF and MO equally contributed &CP and GS shared the last authorship Disclosures Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kralovics:MyeloPro Diagnostics and Research GmbH: Equity Ownership. Soverini:Incyte Biosciences: Consultancy; Bristol Myers Squibb: Consultancy; Novartis: Consultancy. Martinelli:Ariad/Incyte: Consultancy; Celgene: Consultancy, Speakers Bureau; Novartis: Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Amgen: Consultancy; Janssen: Consultancy; Abbvie: Consultancy; Roche: Consultancy; Jazz Pharmaceuticals: Consultancy. Cavo:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Introduction Relapsed/refractory (R/R) AML patients continue to be a formidable clinical challenge, mainly in consideration of associated very poor outcome, with a median overall survival (OS) of less than 12 months. SCT represents the only curative option for these patients. Although, there is no standard-of-care approach which may serve as a bridge to SCT. Our study aims to investigate the effectiveness of MEC regimen as a rescue therapy for R/R AML patients by specifically addressing the CR rate, including minimal residual disease (MRD) negativity, the number of patients who subsequently underwent SCT and the presence of predictive factors of response. Methods Fifty-five consecutive adult AML patients were treated with MEC regimen in our Institution. In patients under 66 years old, we administered mitoxantrone 6 mg/sqm/die from day 1 to day 6, etoposide 100 mg/sqm/die from day 1 to day 6 and cytarabine 1000mg/sqm/die from day 1 to day 6, whereas in patients over 66 years old, the treatment schedule was reduced to 4 consecutive days. Data were retrospectively collected by using RedCap in accordance with Helsinki declaration and GCP. We used Kaplan-Meyer to estimate survival, and log rank to test differences in survival. Chi-squared, fisher's exact test and linear-by-linear correlation were used to test differences in proportions and distributions. Response was defined in accordance with 2017 ELN recommendations. CTCAE 4.03 was used to grade adverse events. MRD was assessed with WT1 or specific fusion transcripts. Results Fifty-five patients received MEC from 2008 to 2018. Age at diagnosis ranged from 17 to 72 years, with a median age of 51 years. Our set was enriched for high-risk patients. Interestingly, twenty percent of patients harbored FLT3-ITD at diagnosis (table 1). Two main groups were included: resistant AML, 28/55 patients (50,9%), and relapsed AML, 27/55 patients (49,1%). At induction, almost half of patients received "3+7" (n=25, 45,5%), while fludarabine-based regimens were administered to 14 patients (25,5%). In our set, after MEC median duration of hospitalization was 30 days (14-78); PMN >500/mm3 was reached after 26 days (range 18-67). Fever and febrile neutropenia was the most recurrent adverse events (AE). AEs were low in grade; out of 80 graded AEs, 38 (47,5%) were grade 2, 27 (33,8%) were grade 3, 9 (11,3%) were grade 4 and only 3 events resulted in death (3,8%). E. coli was the most recurrent cause of infection (10 cases). Overall, 25/55 patients (45,5%) achieved a complete remission (CR) after one course of MEC chemotherapy. Twelve patients (21.9%) achieved MRD negativity and 13 patients (23,6%) obtained an MRD+ CR or had no MRD test. Six patients (10,9%) had a partial response (PR) and 1 patient (1,8%)had hematological improvement (HI). Four patients (7.3%) died during post-MEC aplastic phase. Disease risk at diagnosis and R/R status did not influence the chance to obtain CR (figure 1 A). In 12 patients, a second MEC was administered. Four out of 12 patient improved their response with the 2nd MEC (2 patients obtained MRD - from MRD+ CR, 1 patient obtained PR and 1 patients obtained CR from hematological improvement). MEC was an effective bridge to SCT, 32/55 patients (58,2%, figure 1 B), received SCT; 15/32 patients (46,9%) received SCT directly after the 1st course of MEC, 9/32 patients (28,1%) after the 2nd course of MEC and 2 patients (6,3%) after an additional course of post-remission chemotherapy. Of note, only 6 patients (18,8%), who were not responsive to MEC, underwent SCT after an alternative rescue therapy. Median overall survival (OS) from MEC was 455 days (95% C.I. 307-602 days.); 1-year OS, 3-year OS and 5-years OS were 57,9%, 33,2% and 23,1%, respectively (std. error ± 0,067). Patients who responded to MEC (CR MRD+ or CR MRD- after 1 or 2 courses) had better OS than non-responders (median OS 1389 vs 160 days, p=.003). Stepwise multiple logistic regression analysis with COX-HR model established that pre-MEC R/R status, diagnosis class risk, response to one or two courses of MEC, and SCT were independent predictors of survival in the optimal model. Conclusions Taken together, our data indicate that MEC is an effective salvage regimen with affordable toxicity, and gives a high chance to obtain CR. MEC is particularly useful as a bridge to SCT, and has to be considered as a rescue therapy whenever a clinical trial is not available. *GM and AT equally contributed Disclosures Martinelli: Ariad/incyte: Consultancy; Pfizer: Consultancy; Celgene: Consultancy; Amgen: Consultancy; Janssen: Consultancy; Roche: Consultancy. Cavo:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Background. Clonal hematopoiesis of indeterminate potential (CHIP) is an age-related hematological condition, that has been associated with an increased risk of hematological malignancies and of overall mortality. This excess mortality in subjects with CHIP seems to be related to an increased risk of cardiovascular atherosclerotic diseases (Jaiswal S, NEJM 2014). Our aim was to analyze the prevalence of CHIP in patients with Coronary Artery Disease (CAD) and in a group of selected ultra-centenarians ((age >105 years), since no data hasve been produced until now in such a peculiar population of “super-controls” (Garagnani P, Aging 2013). Methods. We performed whole-exome sequencing (WES) from peripheral-blood cells DNA in 99 patients with angiographically proven severe CAD from the Verona Heart Study (Girelli D, NEJM 2000;), and 79 semisupercentenarians (age >105 years). The mean coverage varied from 30x to 100x (higher in centenarians). We analyzed somatic mutations predicted to alter function in 6 key genes (TET2, ASXL1, DNMT3A, JAK2, PPM1D, TP53), selected as the most frequently detected in CHIP according to literature. Results. The prevalence of CHIP in CAD patients was 18.2%, similarly to the increased prevalence detected in other CAD populations (Jaiswal S, NEJM 2017). On the other hand, CHIP was rare in centenarians (prevalence of 2.5%), a result that contradicts the expected exponential increase of CHIP observed after the age of 70 years in previous studies. This result suggested a kind of “survival bias”, that indirectly supports the pathogenic role of age-related CHIP. An utterly fascinating finding was in the frequency of driver mutations in CAD subjects with CHIP: the majority (85%) of CAD patients presented mutations in TET2. Conclusions. Our outcomes add further insights to the nature of CHIP, which could be seen as a preleukemic condition that also leads to an intrinsic odd of cardiovascular events. The Our outcomes add further insights to the recent hypothesis that links CHIP to an increased risk of cardiovascular disease. The study results raise the question over a possible many-sided clinical and biological significance of CHIP that might depend on the driver mutation. In particular, we propose that TET2-driven CHIP is the most responsible for the higher cardiovascular risk, consistently with the pro-atherosclerotic role of this gene in mouse models (Fuster JJ, Science 2017, Jaiswal S, NEJM 2017). Citation Format: Luca Bertamini, Claudia Sala, Nicola Martinelli, Cristina Papayannidis, Cristina Giuliani, Giovanni Malerba, Paolo Garagnani, Maria Abbondanza Pantaleo, Michele Cavo, Oliviero Olivieri, Giovanni Martinelli, Claudio Franceschi, Domenico Girelli. Clonal hematopoiesis of indeterminate potential (CHIP), centenarians and age-related cardiovascular risk: Is TET2 the culprit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1229.

The interface between metallic bonding layers (NiCoCrAlY) and ceramic coatings of 8% yttria partially stabilized zirconia (YPSZ), produced by air plasma spraying (APS) at different deposition temperatures, was investigated by scanning electron microscopy (SEM) and analytical transmission electron microscopy (ATEM) on transverse thin foils. The presence of an Al-rich amorphous film was ascertained, probably originating during the deposition of the bond coat as a crystalline alumina surface layer. This layer successively remelts, grows and solidifies in the amorphous state due to the rapid heat extraction during plasma spraying. The thickness of this interlayer is a function of the deposition temperature: the higher the substrate temperature during spraying, the thinner the interfacial amorphous film. Columnar YPSZ grains, elongated in the direction perpendicular to the surface and having typical dimensions of 50 nm × 500 nm, are superimposed on the amorphous layer. Equiaxed grains of comparable size extend above the columnar structure. Both columnar and equiaxed grains consist of a metastable tetragonal phase t′, characterized by a higher toughness than the face-centred cubic equilibrium phase. The negative influence of this brittle interlayer, in particular on the adhesion strength of the thermal barrier coating (TBC), was also evaluated by means of four-point bending tests. Results confirm a low adhesion strength between the ceramic and the bond coat in the case of TBCs produced at low deposition temperatures.