Abstract: Background. In multiple myeloma (MM), the role of minimal residual disease (MRD) by multiparameter flow cytometry (MFC) and next-generation sequencing (NGS) is well established (H. Avet-Loiseau et al. IMW 2019, S. Oliva et al. EHA 2020). Aims. The aims of this analysis were the evaluation of (1) the rate of conversion from MRD-positivity (MRD-pos) to MRD-negativity (MRD-neg) with MFC and NGS during maintenance and (2) the impact on progression-free survival (PFS) and overall survival (OS) of MRD-neg with both techniques in different subgroups including different treatment arms. Methods. Newly diagnosed (ND)MM patients (pts) aged ≤65 years were randomized (R1) to receive carfilzomib (K)-lenalidomide (R)-dexamethasone (d) induction followed by autologous stem-cell transplantation (ASCT) and KRd consolidation (KRd_ASCT), 12 KRd cycles (KRd12), or K-cyclophosphamide(C)-d induction followed by ASCT and KCd consolidation (KCd_ASCT). After consolidation, pts were further randomized (R2) to KR vs R maintenance. MRD was assessed every 6 months (m) by 8-color second-generation flow cytometry (sensitivity 10-5) in pts with ≥very good partial response (VGPR). In pts achieving at least a complete response (≥CR), MRD was also assessed by NGS at the same time points (Adaptive Biotechnologies, Seattle, US-WA; sensitivity 10-5-10-6). Logistic regression analysis adjusted for International Staging System (ISS) stage (I vs II/III) and R1 was performed to evaluate the conversion rate from MRD-pos to MRD-neg during maintenance (KR vs R). PFS and OS of MRD-neg vs MRD-pos in the intention-to-treat (ITT) population were evaluated. For these analyses, MFC-pos pts included those who were positive by MRD plus those & lt;VGPR, whereas NGS-pos pts included those who were MRD-pos plus & lt;CR (excluding CR pts not evaluable by NGS). 1-year sustained MRD-neg by MFC and NGS was evaluated in pts with at least 2 samples available at least 1 year apart. Results. Rates of MRD-neg by MFC and NGS before maintenance in the 3 induction/consolidation arms have been previously presented (S. Oliva et al. EHA 2020). At R2, 65% of randomized pts were MRD-neg by MFC (equally distributed in the 2 arms); 39% (48/123) of MRD-pos pts turned MRD-neg after a median of 7.6 m (IQR 6.5-12): 46% (29/63) in KR vs 32% (19/60) in R (OR 2.27; P=0.04) arms. At R2, 72% of pts evaluable for CR were MRD-neg by NGS (equally distributed in the 2 arms); 33% of MRD-pos pts (15/45) became MRD-neg at 10-5: 39% (9/23) in KR vs 27% (6/22) in R arms (=NS). In the ITT analysis, after a median follow-up of 45 m from R1, pts who were MRD-neg before maintenance by both techniques showed a superimposable prolonged PFS and OS vs pts who were MRD-pos: 3-year PFS was 80% vs 52% (HR 0.36, 95% CI 0.26-0.49 P & lt;0.001) in MFC-neg vs MFC-pos pts and 83% vs 55% (HR 0.34, 95% CI 0.22-0.52, P & lt;0.001) in NGS-neg vs NGS-pos pts (Fig. 1A); 3-year OS was 96% vs 79% (HR 0.24, 95% CI 0.14-0.42 P & lt;0.001) in MFC-neg vs MFC-pos pts and 97% vs 82% in NGS-neg vs NGS-pos pts (HR 0.30, 95% CI 0.15-0.61, P & lt;0.001). The favorable impact of MRD-neg on PFS was confirmed in all subgroups, in particular in the high-risk setting. PFS in 1-year sustained MRD-neg was superimposable between MFC and NGS (4-year PFS 88% by MFC and 94% by NGS at 10-5). The impact of pre-maintenance MRD negativity by MFC on PFS was explored in different treatment arms: 3-year PFS was longer in KRd_ASCT vs KRd12 and in KRd_ASCT vs KCd_ASCT arms; MRD-pos pts showed a similar PFS in the 3 arms. The same trend was shown by NGS MRD negativity: 3-year PFS was longer in KRd_ASCT vs KRd12 and in KRd_ASCT vs KCd_ASCT arms. A longer PFS was observed in pre-maintenance MRD-neg pts who were randomized to KR vs R both by MFC (HR 0.51, P=0.02) and NGS (HR 0.38, P=0.03); similar features were observed in MRD-pos pts (Fig. 1B). Conclusions. KR maintenance induced a high rate of conversion from MRD-pos to MRD-neg both by MFC and NGS. The outcomes of pts who were MRD-neg by MFC and NGS at 10-5 were similar, as well as those of pts with 1-year sustained MRD-neg both by MFC and NGS. These clinical findings confirmed a high degree of concordance between these two techniques. MRD-neg pts receiving KRD_ASCT showed a longer PFS (88% at 3 years) than pts receiving KRd12 and KCd_ASCT. KR vs R significantly prolonged PFS even in pts who were MRD-neg before maintenance. Figure 1 Disclosures 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. Petrucci: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; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: 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; Amgen: Honoraria, 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. Jacob:Adaptive Biotechnologies: Current Employment, Current equity holder in publicly-traded company. Gozzetti:Amgen: Honoraria; Takeda: Honoraria; Janssen: Honoraria, Research Funding. Kirsch:Adaptive Biotechnologies: Current Employment. Corradini:KiowaKirin: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Other: Travel and accommodations paid by for; F. Hoffman-La Roche Ltd: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other; BMS: Other; Amgen: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Celgene: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Daiichi Sankyo: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Incyte: Consultancy; Janssen: Consultancy, Honoraria; Kite: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations paid by for. Musto:Amgen: Honoraria; Celgene: Honoraria. Boccadoro:Sanofi: Honoraria, Research Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Research Funding; 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; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. 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; Takeda: Honoraria, 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; Janssen: 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. Gay: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; Janssen: 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; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Adaptive: 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; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; GSK: 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).

Abstract: Abstract 730 Background: Carfilzomib is a novel, irreversible proteasome-inhibitor with a significant activity and favourable toxicity profile. Here we evaluated efficacy and safety of the combination carfilzomib-cyclophosphamide-dexamethasone in elderly (≥ 65 years) newly diagnosed MM patients. Methods: The Bryant and Day two-stage design was used to evaluate both efficacy and safety. Patients received oral cyclophosphamide (300 mg/m2 on days 1,8,15), oral dexamethasone (40 mg on days 1, 8, 15, 22) and iv carfilzomib (20 mg/m2 on days 1, 2, and 36 mg/m2 on days 8, 9, 15, 16, cycle 1; 36 mg/m2 on days 1, 2, 8, 9, 15, 16, cycles 2–9) every 28 days for 9 cycles, followed by maintenance with iv carfilzomib (36 mg/m2 on days 1, 2, 15, 16) every 28 days until progression or intolerance. Results: Thirty-four patients were enrolled: median age was 70 years, 21% of patients were older than 75 years, 24% had reduced creatinine clearance ( 〈 50 mL/min), 46% had ISS stage III, and 28% had unfavorable FISH [t(4;14) or t (14;16) or del17p]. Nineteen patients were evaluated for response and for safety after at least 4 cycles (table). All patients achieved at least partial response (PR), 74% at least very good partial response (VGPR), 42% at least complete response (CR)/ near-CR, including 10% stringent-CR. Responses were rapid with the median time to PR of 1 month and the median time to CR of 2 months. After a median follow-up of 7.5 months no patient has progressed or died. Grade (G) 4 hematologic toxicities included neutropenia (1 patient, 5%). At least one G3-4 non-hematologic event was reported in 4 patients (21%): pneumonia and bronchitis (2 patients, 10%), atrial fibrillation (1 patient, 5%) and renal failure (1 patient, 5%). Only 1 patient (5%) developed G1 peripheral neuropathy. No patient discontinued treatment and 4 patients (21%) required carfilzomib dose reductions due to adverse events (G4 neutropenia, G3 pneumonia, G3 atrial fibrillation and G3 renal failure). Conclusions: Carfilzomib-cyclophosphamide-dexamethasone showed encouraging activity in patients with newly diagnosed MM. The combination was well tolerated with a frequency of at least one G3-4 non-hematologic adverse event of 21%. Results will be updated at the meeting. Disclosures: Palumbo: Onyx: Honoraria. Bringhen:Onyx: Honoraria.

Abstract: Abstract 350 Background. The incorporation of new drugs as induction therapy before autologous transplantation appears to produce a high proportion of complete responses, slightly superior to those achieved by conventional chemotherapy with new drugs. Randomized trials are needed to directly compare current best chemotherapeutic approach with best autologous transplantation strategy. Aims. To compare melphalan, prednisone and lenalidomide (MPR) with tandem melphalan (200 mg/m2) (MEL200) in patients younger than 65 years. Methods. As induction, all (N=402) patients received four 28-day cycles of lenalidomide (25 mg days 1-21) and low-dose dexamethasone (40mg days 1,8,15,22) (Rd). Cyclophosphamide (4 g/m2) plus granulocyte-colony stimulating factor was used to mobilize stem cells. As consolidation, patients (N=202) randomized to MPR received six 28-day cycles of melphalan (0.18 mg/kg days 1-4), prednisone (2 mg/kg days 1-4) and lenalidomide (10mg days 1-21); patients (N=200) randomized to MEL200 received tandem melphalan 200 mg/m2 with stem-cell support. All patients were also randomized to receive either aspirin or low-molecular weight heparin (enoxaparin) as thromboprophylaxis. Primary end point was progression-free survival; data were analyzed in intention-to-treat. Results. Patient characteristics were similar in both groups, median age was 58 years. After Rd induction, at least partial response (PR) rate was 84%, at least very good partial response (VGPR) was 32% including 5% complete response (CR). The median yields of CD34+ cells harvested was 10 ×106 CD34+ cells/Kg; 94% of patients collected the minimum dose of 2×106/kg CD34+ cells. After 3 cycles of MPR, at least VGPR rate was 51% and CR 11%. After the first MEL200, at least VGPR rate was 56% and CR 14%. No difference in responses were reported according to cytogenetic abnormalities, such as del13, t(4;14) and t(14;16). After a median follow-up of 12 months, 1-year progression-free survival was 96% for MPR and 94% for MEL200 (p=.92) 1-year overall survival was 98% for MPR and 99% for MEL200 (p=.94). During Rd induction, the most frequent grade 3-4 adverse events were neutropenia (9%), anemia (8%), infections (4%), skin rash (4%), fatigue (2%) and thromboembolic events (1%). During consolidation, the incidence of grade 3-4 neutropenia (97% vs 34%, p 〈 .001) thrombocytopenia (97% vs 16%, p 〈 .001), infections (21% vs 3%, p 〈 .001) and gastrointestinal (17% vs 1%, p 〈 .001) complications was higher in MEL200 patients The incidence of thromboembolic events was similar in patients randomized to receive aspirin (2%) or enoxaparin (1%) as thromboprophylaxis (p=.42). Conclusion. Rd is an effective and safe induction regimen. Both MPR andMEL200 improved the quality of response, achieved by Rd induction. At present, progression-free and overall survival are not significantly different in the two groups, but longer follow-up is needed. Both aspirin and enoxaparin were equally effective as thromboprophylaxis. These data will be updated at the meeting. Disclosures: Palumbo: CELGENE: Honoraria. Cavallo:CELGENE: Honoraria. Patriarca:CELGENE: Honoraria. Caravita:CELGENE: CONSULTANCY. Boccadoro:CELGENE: CONSULTANCY, ADVISORY COMMITTEES, Research Funding.

Abstract: Introduction .Treatment of multiple myeloma (MM) patients (pts) has radically changed over the last years following the introduction of next generation proteasome inhibitors (PI) and immunomodulatory derivatives (IMiDs). Despite the improvement of pts' outcome due to these drugs, MM remainsan incurable disease given its propensity for clonal heterogeneity and its complex interaction with the surrounding bone marrow microenvironment. Almost all pts eventually relapse despite their responses to PI, IMiDs or both. Recently, one further therapeutic option for MM patients is represented bydaratumumab, an anti-CD38 monoclonal antibody approved alsofor heavily pre-treated pts who have exhausted all other therapeutic options. Patients and Methods. We report the experience of the Multiple Myeloma GIMEMA Lazio Group in 50 relapsed/refractory MM pts treated with daratumumab as monotherapy. Twenty-nine pts (58%) were men and 21 (32%) women. According to the ISS,24 pts (48%) were ISS I, 11 (22%) ISS II, 7 (14%) ISS III and 8(16%)not evaluable. According toDurie & Salmon, 20 pts (40%) were 1 A, 2 (4%) 1 B, 12 (24%) II A, 1 (2%) II B,7 (14%) III A, 3 (6%) III B and 5 (10%) not evaluable. Isotype IgG-k was found in 21 pts (42%), IgG-λ in 13 (26%), IgA-k in 6 (12%), IgA-λ in 3 (6%), micromolecular k in 5 (10%) andmicromolecular λ in 2 (4%). Median age was 62.3 years (range, 43.1 - 85.7); 32 pts (64%) were refractory to the last line of therapy; 26 (52%) had previously received a stem cell transplant (13 single autologous, 12 tandem autologous and one an autologous followed by an allogeneic transplant). After a median follow-up from diagnosis of 54.5 months (range 1.0 - 203.0) and a median of 3 previous lines of therapy (range 2 - 8), pts received a median of 3 cycles (range 1 - 23) of daratumumab. Results.Forty-seven pts (94%) performed at least one cycle and were evaluable for response. The overall response rate was 74%; in particular, 2 pts obtained a CR (4.2%), 3 pts a VGPR (6.3%), 17 pts a PR (36.2%) and 15 pts a SD (32%), while 10 pts (21.3%) presented a PD. After a median follow-up of 5.3 months (range 1 - 31) ,24 pts(65%) were still in response and alive, one pt (5.8%) died in PR due to post-allograft GVHD and 12 (32%) experienced a PD (1 CR, 1 VGPR, 6 PR and 4 SD). Seven (19%) pts died and 30 (81%) are still alive. With regard to the 3 pts not evaluable for response, 2 died early and 1 has not yet completed the first cycle. The median time to response, duration of response, progression-free survival and overall survival were 1.5 months (range 1.0 - 6.0), 6.7 months (95% CI, 4.14 - 14.21), 5.7 months (95% CI, 3.26 - 13.75) and 22.5 months (95% CI, 11.6 - 36.1), respectively. Daratumumab was well tolerated; the most common adverse events, of any grade, were infections in 20 pts (42.0%) and anaemia in 21 pts (44.0%), which did not lead to treatment discontinuation. Infusion-related reactionswere observed in 7pts (14.8%), grade I-II (4 pts), grade III (3 pts). Conclusions.Daratumumab monotherapy is an effective strategy for heavily pre-treated and refractory pts with multiple myeloma, with a favorable safety profile. This treatment option needs to be considered for pts not eligible for combination therapy of daratumumab with bortezomib or lenalidomide, recently approved also in our country. Disclosures Vozella: Takeda Oncology; Amgen: Honoraria. Annibali:Celgene; Takeda; Amgen, Janssen Cilag: Honoraria. Caravita di Toritto:Johnson & Johnson: Other: Advisory Board, Travel and Accomodation EHA; Amgen: Other: Advisory Board; Bristol-Myers Squibb: Honoraria, Other: Travel and Accomodation EMN; Takeda: Other: Advisory Board; Celgene: Other: Advisory Board, Travel and Accomodation ASH, Research Funding. Foà:NOVARTIS: Speakers Bureau; JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; GILEAD: Speakers Bureau; AMGEN: Other: ADVISORY BOARD; INCYTE: Other: ADVISORY BOARD; CELTRION: Other: ADVISORY BOARD; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau; ROCHE: Other: ADVISORY BOARD, Speakers Bureau. Petrucci:Takeda Oncology; Amgen; Celgene; BMS; Janssen Cilag: Honoraria, Other: Advisory Board.

Abstract: Introduction Elotuzumab (Elo), an immunostimulatory monoclonal antibody targeting signaling lymphocytic activation molecule F7 (SLAMF7), received marketing approval in Italy for relapsed or refractory multiple myeloma (RRMM), in combination with lenalidomide (R) and dexamethasone (d) (EloRd) in April 2017. Here we report preliminary data of an Italian real-life experience on EloRd as salvage therapy for RRMM patients treated outside of controlled clinical trials. The primary objectives of this study were to assess the toxicity profile and the efficacy of EloRd administered as salvage therapy in a real-world setting. Methods Retrospective data collection received approval from local ethic committee. The cohort included 180 RRMM patients from 28 Italian centers who received at least one cycle of EloRd as salvage treatment between April 2017 and June 2018. Patients were treated with EloRD according to marketing approval as follows: Elo 10 mg/kg i.v. on days 1, 8, 15, and 22 during the first two cycles and then on days 1 and 15 of each following cycle, R 25 mg on days 1 to 21 of each cycle and d at a dose of 40 mg during the week without Elo, and 36 mg on the day of Elo administration. Responsive patients had to reach at least a partial remission (PR). Results Baseline characteristics are shown in Table 1. Median age of the 180 patients was 72 years (range 48-89 years); 53.9% were males (Table 1). The median number of previous therapy regimens was 1 (range 1-7); 69 patients (38.3%) received a previous autologous stem cell transplantation (ASCT). One hundred and ten patients (61.1%) showed a symptomatic relapse, 36 (20%) a biochemical relapse, and 34 cases (18.9%) were refractory to the last therapy, including bortezomib in 12.8% of patients. Forty-four patients (24.4%) had creatinine clearance ≤60 mL/min. Among the 138 cases evaluable for International Scoring System (ISS), 54 (39.1%) had stage I, 56 (40.6%) stage II, and 28 (20.3%) stage III. At last data collection (June 2018), 164 cases were evaluable for response. The median number of courses administered so far was 5 (range 1-18). The overall response rate (ORR) was 78%, with 9 complete remissions (CRs) (5.5%) and 49 very good partial remissions (VGPRs) (35.4%). A significant higher ORR was observed in patients who had received only 1 previous line of therapy than those who had received 〉 1 line (64% vs 37.5%; p=0.004). Age ( 〈 70 vs ≥70 years), sex, previous ASCT, creatinine clearance ( 〈 60 vs ≥60 mL/min), ISS stage (I vs II vs III), time from diagnosis to EloRd start (≥3.5 years vs 〈 3.5 years), status of the disease at EloRd start (biochemical relapse vs symptomatic relapse vs refractory to last therapy) did not significantly impact on the probability of achieving a response. The median time to first response was 1.6 months, while the median time to best response 2.8 months. After a median follow-up of 6 months (range 1-18 months) 33 patients stopped treatment due to disease progression and 4 due to toxicity (2 cases after 1 cycle for pneumonia, 1 after 1 cycle for dexamethasone-related psychosis, and 1 after 2 cycles for lenalidomide-related severe skin rash). A total of 17 patients died (7 patients from progressive disease; 2 from an infection; 1 from a second neoplasia; 7 from causes unrelated to therapy). Follow-up data regarding PFS and overall survival are not sufficiently mature to be analyzed. Common grade 3 or 4 adverse events were fatigue (18.9%), anemia (17%), neutropenia (16.5%), lymphocytopenia (15.9%), and pneumonia (15.9%). Infusion reactions occurred in 13 patients (7.2%) and were always of grade 1 or 2. Infusion reactions resolved in all patients and no case discontinued treatment. Conclusions Our real world preliminary data confirm that EloRd is an effective and safe regimen for RRMM patients, particularly if used as first salvage regimen, basically resembling results obtained in controlled clinical trials. Table 1. Table 1. Disclosures Galli: Celgene: Honoraria; Janssen: Honoraria; Sigma-Tau: Honoraria; Bristol-Myers Squibb: Honoraria. Giuliani:Janssen Pharmaceutica: Other: Avisory Board, Research Funding; Celgene Italy: Other: Avisory Board, Research Funding; Takeda Pharmaceutical Co: Research Funding. Mangiacavalli:Janssen: Consultancy; Celgene: Consultancy; Cilag: Consultancy. Ballanti:Celgene: Honoraria; Janssen: Honoraria; Amgen: Honoraria; BMS: Honoraria. Montefusco:Celgene: Other: Advisory Board; Amgen: Other: Advisory Board; Janssen: Other: Advisory Board. Bringhen:Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Amgen: Honoraria, Other: Advisory Board; Janssen: Honoraria, Other: Advisory Board; Takeda: Consultancy. Zamagni:Amgen: 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; Janssen: 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; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees. Patriarca:Celgene: Other: Advisory Role; Travel, accommodations, expenses; Janssen: Other: Advisory role; Jazz: Other: Travel, accommodations, expenses; Medac: Other: Travel, accommodations, expenses; MSD Italy: Other: Advisory Role. Di Raimondo:Takeda: Honoraria, Research Funding; Celgene: Honoraria. Petrucci:Takeda Oncology; Amgen; Celgene; BMS; Janssen Cilag: Honoraria, Other: Advisory Board. Offidani:Bristol-Myers Squibb: Honoraria, Other: Advisory Board; Amgen: Honoraria, Other: Advisory Board; Takeda: Honoraria, Other: Advisory Board; Janssen: Honoraria, Other: Advisory Board; Celgene: Honoraria, Other: Advisory Board.

Abstract: Patients with Philadelphia chromosome clones emerging during imatinib therapy were studied and followed over time. None of the patients presented with clinical and laboratory signs of myelodysplastic syndrome after up to 49 months of follow‐up.