Citations

Abstract Background: Isatuximab (SAR650984) is a humanized IgG1 monoclonal antibody that binds selectively to a unique epitope on the human CD38 receptor. In the dose escalation part of the Phase I portion of the trial (NCT01749969), isatuximab ≥10 mg/kg IV given every other week (q2w) or 10 mg/kg weekly (qw) induced responses in 6/19 recipients (ORR 32%). Responses were noted at doses as low as 1 mg/kg q2w. The maximum tolerated dose (up to 20 mg/kg IV qw) was not reached. The most common treatment-emergent adverse events (TEAEs) were fatigue and nausea; few serious grade 3/4 TEAEs were reported (pneumonia 6%). The most common category of drug-related TEAE involved infusion-associated reactions (IARs) occurring in half of the patients, with grade 3/4 IARs in <5% of the patients. Based on promising Phase I activity, a Phase II dose finding study was added to investigate single-agent isatuximab in patients with relapsed or refractory myeloma (RRMM). Methods: In Phase II, eligible patients were originally randomly assigned (1:1:1) to one of 3 treatment groups: 3 mg/kg q2w, 10 mg/kg q2w, and 10 mg/kg q2w x 4 doses then q4w. A 4th treatment group was enrolled at a higher isatuximab dose with an optimized schedule of 20 mg/kg qw x 4 doses then q2w. Patient assignment was stratified by prior anti-myeloma therapy (Stratum 1: prior treatment with pomalidomide (POM) and/or carfilzomib (CAR); Stratum 2: no prior POM or CAR). Patients continued therapy until disease progression, unacceptable AEs or physician/patient decision. Eligible patients had measurable disease (serum M-protein >1 g/dL or urine M-protein ≥200 mg/24 h, or serum free light chain ≥10 mg/dL), prior exposure to ≥3 lines of anti-myeloma therapy or were double-refractory to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs), prior treatment with an alkylating agent, and adequate baseline bone marrow reserve and organ function. Enrollment of 24 patients was planned for each treatment group. An interim efficacy analysis is planned when all patients have completed ≥2 disease assessments, with central review of these data currently ongoing. Enrollment has now been completed and all patients who completed at least 1 cycle of isatuximab at the cutoff date (5/29/15) are included in this preliminary analysis. Results: Patient characteristics (n=96): median age 62.5 yrs (range 38-85); median time from initial diagnosis to study treatment 5.85 yrs (1.2-24.1); 76% had IgA/G MM; 24% had light-chain only disease; and 22%, 22%, and 44% had Stage I, II, and III disease, respectively. The median number of prior lines of therapy was 5 (2-14) with 100%, 99%, and 98% having prior exposure to PIs, IMiDs, and alkylator-containing therapy, respectively. Overall, 78% of patients had previously received POM and/or CAR; 55% had been exposed to both of these agents. At data cut-off, 36.5% of patients remained on therapy and 53.1%, 6.3%, and 4.2% had discontinued therapy due to disease progression, AEs, or other reason, respectively. The median number of cycles received was 3 (1-9), with a median duration of treatment of 11.7 wks. Approximately 17% of patients required at least 1 dose delay and 7.3% of isatuximab infusions were interrupted. TEAEs occurred in 93% of patients, with 51% being grade ≥3. Drug-related TEAEs occurred in 61% of patients (grade ≥3, 10%). The most common drug-related TEAEs (>5% of patients) were nausea (14.6%), chills (14.6%), dyspnea (13.5%), chest discomfort (10.4%), flushing (7.3%), headache (7.3%), cough (6.3%), and vomiting (5.2%). The majority of the symptoms occurred within 24 h of isatuximab infusion and were attributed to an IAR. IARs occurred in 50% of patients, were predominantly grade 1/2 (grade ≥3, 3.1%), and were mostly limited to Cycle 1 (2 patients had IARs in Cycle 2). Pneumonia (6.3%) and sepsis (5.2%) were the most common serious TEAEs. Six deaths have occurred within 30 days of last dose, 4 due to disease progression, and 2 due to serious AEs unrelated to study therapy (cardiopulmonary arrest and cerebral hemorrhage). Conclusion: Isatuximab administered to heavily pre-treated patients with RRMM appears well tolerated. IARs are common in Cycle 1, but typically do not recur. Results by treatment arm, including interim analysis response data, will be presented. Disclosures Martin: Sanofi: Research Funding. Richter:Takeda: Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Speakers Bureau; Amgen: Speakers Bureau; Novartis: Speakers Bureau. Vij:Millennium: Honoraria, Speakers Bureau; Onyx: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy; Takeda: Consultancy, Research Funding; Novartis: Consultancy; Sanofi: Consultancy; Janssen: Consultancy; Merck: Consultancy. Zonder:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS, Amgen, Prothena, Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Kaufman:Spectrum: Consultancy; Merck: Research Funding; Onyx: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Millenium: Consultancy. Bensinger:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acetylon: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Research Funding, Speakers Bureau; Millenium: Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dimopoulos:Novartis: Honoraria; Amgen: Honoraria; Genesis: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Onyx: Honoraria; Janssen-Cilag: Honoraria. San Miguel:Millennium, Celgene, Novartis, Janssen, Onyx, BMS, MSD: Membership on an entity's Board of Directors or advisory committees. Zimmerman:Onyx: Honoraria; Celgene: Honoraria, Speakers Bureau; Millennium: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Hari:Celgene: Consultancy; Takeda: Consultancy; BMS: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Spectrum: Consultancy; Sanofi: Consultancy. Gasparetto:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Honoraria; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kumar:Skyline, Noxxon: Honoraria; Celgene, Millennium, Onyx, Janssen, Noxxon, Sanofi, BMS, Skyline: Consultancy; Celgene, Millennium, Onyx, Novartis, Janssen, Sanofi: Research Funding. Hsu:Sanofi: Employment. Charpentier:Sanofi: Employment. Strickland:Alexion Pharmaceuticals: Other: Advisory Board Particpation; Amgen: Other: Advisory Board Particpation; Daiichi-Sankyo: Other: Advisory Board Particpation; Boehringer-Ingelheim: Other: Advisory Board Particpation; Sunesis Pharmaceuticals: Other: Steering Committee and Advisory Board Participation. Mikhael:Sanofi: Research Funding; Onyx: Research Funding; Celgene: Research Funding; AbbVie: Research Funding.

Abstract Background Long-term outcomes from autologous stem cell transplant (ASCT) in patients (pts) with relapsed/refractory (R/R) Hodgkin lymphoma (HL) are significantly better in patients who achieve a complete remission (CR) from salvage chemotherapy prior to ASCT. However, standard salvage therapy produces variable CR rates (19%-60%) and is associated with significant toxicity. Brentuximab vedotin and bendamustine are highly active when administered as single agents to pts with R/R HL (34% and 33% CR rates, respectively) and have manageable safety profiles. This phase 1/2, single-arm, 2-stage, open-label study was designed to evaluate the safety and efficacy of brentuximab vedotin in combination with bendamustine for the treatment of pts with primary refractory disease or in first relapse (ClinicalTrials.gov #NCT01874054). Methods Pts received an outpatient IV infusion of 1.8 mg/kg brentuximab vedotin on Day 1 with bendamustine on Days 1 and 2 of 3-week cycles for up to 6 cycles. Pts could undergo ASCT any time after Cycle 2 and post-transplant resume treatment with brentuximab vedotin as monotherapy for up to 16 total doses. Phase 1 was designed to determine the recommended dose of bendamustine, with an initial dose of 90 mg/m2 and a de-escalation scheme to be implemented if it exceeded the maximum tolerated dose. During phase 2, bendamustine was administered at the recommended dose in order to assess the CR rate of the combination. Response was assessed by the investigator per Cheson 2007. Enrollment is complete and long-term follow-up for PFS and OS continues. Results Fifty-five pts (56% female) with a median age of 36 yrs (range, 19-79) were enrolled. Fifty-one percent of pts had relapsed disease and 49% of pts had primary refractory disease after frontline therapy. A median of 13.8 mos (range, 3-98) had elapsed since initial diagnosis. No dose-limiting toxicities were observed in the safety cohort, thus the recommended dose of bendamustine in combination with brentuximab vedotin was 90 mg/m2. Pts received a median of 2 cycles (range, 1-6) of the combination and a median of 9 cycles (range, 1-14) of single-agent brentuximab vedotin. The main toxicity observed with the combination was infusion-related reactions (56% overall). The most common symptoms (≥10%) were pyrexia (26%), chills (20%), dyspnea and nausea (15% each), flushing (13%), and hypotension (11%). Premedication with corticosteroids and antihistamines was instituted with a protocol amendment and appeared effective. Before the amendment, 6 pts (24% of treated pts) discontinued treatment prematurely because of IRRs; post-amendment, IRRs led to treatment discontinuation for 2 pts (7%). The CR rate of the combination was 74% (39/53 pts evaluable for response) and the overall objective response rate (CR and partial remission) was 93% (49/53 pts). The CR rate was 64% and 84% for refractory and relapsed pts, respectively. Stem cell collection after first-line mobilization (G-CSF± plerixafor) was successful in 93% of pts (37/40). Median number of CD34+ cells collected was 4.1 x106 (Q1, Q3: 3.0, 5.4) in a median of 2 (range, 1-5) apheresis sessions. Median time to neutrophil and platelet engraftment was 11 days (range, 9-21) and 13 days (range, 9-39), respectively. Pts have been followed for a median of approximately 1 year from first dose (median = 418 days; range, 118-635) and approximately 10 mos (314 days; range, 13-553) from ASCT. To date, 12 progression events have been observed: 7 in the 40 pts who underwent transplant and 5 in the 13 pts who did not undergo transplant. The estimated 12-mos PFS is 80% for both the transplanted population (95% CI: 70%, 90%) and the overall population (95% CI: 60%, 90%). Three of the 12 progression events were deaths; 2 pts died from progression of their HL and 1 pt died from septic shock after transplant. Conclusions The outpatient regimen of brentuximab vedotin 1.8 mg/kg on Day 1 in combination with bendamustine 90 mg/m2 on Days 1 and 2 of 3-week cycles induced a very high CR rate that compares favorably with historical data. The regimen has a manageable safety profile, with the most significant side effect being IRRs that can be successfully managed by premedication. The estimated 12-mos PFS rate of 80% demonstrates response durability, making the combination a promising salvage regimen for pts with HL in the first relapse setting. Progression-Free Survival Figure 1. Figure 1. Disclosures Off Label Use: Brentuximab vedotin is indicated in the US for treatment of patients with Hodgkin lymphoma after failure of autologous stem cell transplant or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates and for the treatment of patients with systemic anaplastic large cell lymphoma after failure of at least one prior multi-agent chemotherapy regimen. This study evaluates brentuximab vedotin in HL patients with primary refractory disease or in first relapse. . Sawas:Seattle Genetics, Inc.: Research Funding. Agura:Seattle Genetics, Inc.: Research Funding. Matous:Takeda Pharmaceuticals International Co.: Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Seattle Genetics, Inc.: Research Funding, Speakers Bureau. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding. Crosswell:KIYATEC (employment); Gilead (common stock ownership and research funding): Employment, Equity Ownership, Research Funding. Islas-Ohlmayer:Seattle Genetics, Inc.: Research Funding. Behler:Seattle Genetics, Inc.: Research Funding; Onyx Pharmaceuticals: Speakers Bureau. Cheung:Seattle Genetics, Inc.: Research Funding. Forero-Torres:Seattle Genetics, Inc.: Research Funding. Vose:Seattle Genetics, Inc.: Honoraria, Research Funding. Josephson:Seattle Genetics, Inc.: Employment, Equity Ownership. Advani:Seattle Genetics, Inc.: Research Funding; Genetech: Consultancy.

Background: Serum folate (SF), vitamin B12 (B12), and iron deficiencies (def) are common causes of nutritional anemias. These deficiencies are usually multifactorial, with nutritional and non-nutritional factors playing a role. SF, B12, and iron levels are usually ordered in the setting of anemia, and malnutrition with or without neurologic symptoms. Since folic acid fortification, the prevalence of SF def in the United States (US) is <1% in the general population. B12 def and iron def range between 6-12%, and 1-11% respectively depending on the population studied. The prevalence of nutritional anemias secondary to SF, B12, and/or iron def by racial groups in the US is poorly studied, and most data available focuses on non-Hispanic whites (NHW). We aimed to determine the prevalence of anemia secondary to nutritional deficiencies by racial groups in the US. Methods: We performed a retrospective analysis of patients with SF, B12 and iron levels at Mayo Clinic Arizona between 01/2010 and 10/2018. Race was classified according to the NIH criteria. Normal laboratory values were determined according to our lab reference and the US National Health and Nutrition Examination Survey (NHANES) III. SF levels (mcg/Lt) were defined as deficient <4, normal ≥4.0, and excess ≥20. B12 levels (ng/L) as deficient <150, borderline 150-400, normal >400-900, and excess ≥900. Iron def was determined by ferritin levels (mcg/L) as low <24, normal 24-336, elevated ≥336 for men, low <11, normal 11-307, elevated ≥307 for women. Demographics and clinical variables were compared between groups by chi-square test for frequency data or Kruskal Wallis rank-sum test for continuous variables. Multivariable logistic regression was used for a sample-level analysis adjusting for age and gender and using NHW as a reference group. Results: A total of 79,926 SF, 107,731 B12, and 39,827 ferritin samples from 67,683 patients were analyzed. Demographics and sample analysis are presented in Table 1. In the sample-level analysis, 23,008 (25%) had anemia with higher prevalence in the American Indian/Alaskan Native (AI/AN) 49% and African Americans (AA) 43% (p<0.001). The prevalence of SF def was 446/79,926 (0.6%), B12 def 1,548/107,731 (1.4%), and iron def 5,212/39,827 (13.1%). 23 had concomitant SF and B12 deficiency, 25 SF and iron def, and 144 B12 and iron def. The SF def prevalence by racial groups was: AI/AN 11 (1.9%), AA 19 (1.1%), NHW 378 (0.6%), Hispanic 28 (0.5%), Asian 4 (0.2%). The B12 def prevalence by racial groups was: Asian 89 (3.4%), NHW 1,274 (1.4%), Hispanic 87 (1.3%), AA 30 (1.3%), AI/AN 10 (1.3%). Iron def prevalence by racial groups: AI/AN 71 (20.5%), Asian 198 (17.6%), AA 180 (16.9%), Hispanic 432 (15.6%), NHW 4,161 (12.4%). In the multivariate sample-level analysis, the presence of anemia was higher in the AI/AN (OR: 4.51, 95%CI: 3.70-5.49, p<0.0001), AA (OR 3.34, 95%CI: 2.99-3.74, p<0.0001), Asian (OR 1.52, 95%CI: 1.35-1.73, p<0.0001) and Hispanic racial group (OR 1.41, 95%CI: 1.30-1.52, p<0.0001). SF def was more common in the AI/AN (OR: 2.94, 95%CI: 1.60-5.39, p<0.001) and AA (OR 1.71, 95%CI: 1.08-1.53, p=0.02). B12 def was more common in the Asian racial group (OR: 2.535, 95%CI: 20.03-3.16, p<0.0001). Iron def was more common in the AI/AN (OR: 1.62, 95%CI: 1.21-2.17, p<0.001), Asian (OR 1.31, 95%CI: 1.0-1.57, p=0.003), and AA racial group (OR 1.26, 95%CI: 1.05-1.52, p=0.001). Conclusions: In our cohort, we show that despite the low prevalence of nutritional anemias in the US, racial disparities exist. Major differences were observed in the prevalence of anemia, SF def and iron def especially among AI/AN and AA. These differences may be linked to medical causes, nutritional practices and other social determinants of health. More research regarding the causes of these disparities and its clinical implications on a population level are needed. Targeted strategies to improve folate, B12 and iron intake in at higher risk populations could decrease adverse outcomes and decrease healthcare disparities caused by nutritional anemias. T able 1. Sample-level comparison by race Disclosures No relevant conflicts of interest to declare.

Introduction: The phase 3 international, randomized, double-blind ROBUST clinical trial (NCT02285062) compared progression-free survival between patients with previously untreated ABC-type DLBCL treated with placebo plus rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (placebo-R-CHOP) versus lenalidomide + R-CHOP (R2-CHOP) for 6 21-day cycles. HRQoL, as measured by the Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) and the EuroQoL 5-dimension 3-level (EQ-5D-3L) patient-reported questionnaires, was evaluated as a secondary endpoint for the 2 treatment arms. Methods: For each treatment group, FACT-Lym and EQ-5D-3L scores were measured at baseline (BL), mid-, end-of-treatment (EOT), and post-treatment, in 12-week intervals from Week 34 onward. Patients were evaluated if they had completed BL and ≥ 1 post-BL calculable FACT-Lym subscale measurements. Non-inferiority (NI) of R2-CHOP versus placebo-R-CHOP was measured for 4 key FACT-Lym subscales: Physical Well-Being (PWB), Additional Concerns (AC), Functional Well-Being (FWB), and Trial Outcome Index (TOI). NI was assessed at EOT (typically 3-4 weeks after completing Cycle 6) and at post-treatment follow-up at Week 34 by analysis of covariance (ANCOVA). The NI margins were prespecified as 1 less than the higher published minimal important difference (MID) for each subscale. Since a range of MIDs have been published, a more conservative value was also used as a sensitivity analysis. Time to improvement (TTI), using published responder definitions, was also assessed for the FACT-Lym subscales. EQ-5D-3L scores were summarized descriptively. Results: Demographic and baseline disease characteristics were balanced across the 2 treatment arms (N = 285 per arm). The percentage of patients who completed the FACT-Lym out of the expected population remained &gt; 85% at all time points with &gt; 50 patients still on the study in each treatment arm up to Week 142. Completion rates and reasons for missing assessments were balanced across the 2 treatment arms. FACT-Lym subscale scores were generally higher after EOT, similar for both treatment groups, and mean changes from BL were close to or above MID (where defined), except for the Social/Family Well-Being subscale. Mean differences in FACT-Lym TOI between treatment arms are shown in Table 1. As positive treatment differences favor R2-CHOP and -10 was the predefined NI margin, NI was demonstrated for the FACT-Lym TOI subscale at both EOT and Week 34 assessments. Superiority of R2-CHOP was demonstrated at EOT as the confidence interval (CI) lies completely above 0 (P &lt; 0.04); however, this difference was not clinically meaningful. Furthermore, NI was also demonstrated when using the sensitivity analysis margin of -4.5. ANCOVA models were also fitted for the other key subscales of PWB, AC and FWB (Table 2). NI was demonstrated for all NI margins at both time points for the PWB and AC subscales. The FACT-Lym FWB subscale demonstrated NI for both margins at EOT and Week 34 for the primary NI margin of -2 based on the MID minus 1, but did not demonstrate NI when an NI margin of -1, based on an alternative published MID, was used. The TTI curves and associated summary statistics were similar for the 2 treatment arms, with a median TTI for the FACT-Lym TOI of 21 weeks (95% CI 15-22) for patients treated with R2-CHOP and 18 weeks (95% CI 15-22) for patients treated with placebo-R-CHOP. Mean EQ-5D-3L visual analogue scale (VAS) and Utility Index (UK weights) change from baseline scores were higher in both treatment arms and the mean changes were above, or close to, the published MID (7 for VAS, 0.1 for Utility Index) at EOT assessments. Prespecified sensitivity and subgroup analyses supported the conclusions from the primary HRQoL analyses. Conclusions: The predefined NI levels were met for the 4 key FACT-Lym subscales. Similar results were observed across the other HRQoL assessments, sensitivity, and subgroup analyses. Adding lenalidomide to the R-CHOP regimen did not adversely affect the HRQoL of patients with DLBCL as measured by FACT-Lym and EQ-5D-3L. These data serve as a benchmark for future clinical trials combining next-generation immunomodulatory drugs with standard R-CHOP to improve clinical efficacy while maintaining HRQoL in patients with DLBCL. HRQoL analyses should become an integral part of future clinical trials of novel combination regimens in DLBCL. Disclosures Chiappella: Roche: Speakers Bureau; Teva: Speakers Bureau; Servier: Other: advisory board, Speakers Bureau; Janssen: Other: advisory board, Speakers Bureau; Celgene: Other: advisory board, Speakers Bureau. Cocks:Adelphi Values: Employment; Amgen: Consultancy; BMS: Consultancy; Celgene Corporation: Consultancy; Endomag Ltd.: Consultancy. Greenwood:Adelphi Values: Employment. Williams:Adelphi Values: Employment. Scott:Celgene: Consultancy; Roche/Genentech: Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding; Janssen: Consultancy, Research Funding. Yamamoto:SymBio: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria; Sanofi: Honoraria; Astra-Zeneca: Consultancy, Research Funding; Sumitomo Dainippon: Honoraria; Chugai: Consultancy, Honoraria, Research Funding; Eisai: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; Gilead Sciences: Research Funding; Solasia Pharma: Research Funding; Bayer: Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; ARIAD: Research Funding; Pfizer: Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Kyowa Kirin: Honoraria; MSD: Consultancy, Honoraria; Mundipharma: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Research Funding; Meiji Seika Pharma: Consultancy, Honoraria; HUYA/IQVIA Services Japan: Consultancy, Honoraria; Novartis: Honoraria, Research Funding; Incyte: Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Jurczak:Bayer: Research Funding; Takeda: Research Funding; Gilead: Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Morphosys: Research Funding; Incyte: Research Funding; Celgene Corporation: Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celtrion: Research Funding; Novo Nordisk: Research Funding; Servier: Research Funding; TG Therapeutics: Research Funding. Özcan:Sanofi: Other: Travel support; Abdi Ibrahim: Other: Travel support; BMS: Other: Travel support; Takeda: Honoraria, Other: Travel support, Research Funding; Archigen: Research Funding; Roche: Other: Travel support, Research Funding; Bayer: Research Funding; Janssen: Other: Travel support, Research Funding; Celgene Corporation: Research Funding, Travel support; AbbVie: Other: Travel support, Research Funding; MSD: Research Funding; Novartis: Research Funding; Jazz: Other: Travel support; Amgen: Honoraria, Other: Travel support. Belada:Roche: Consultancy; Gilead Sciences: Consultancy; Takeda: Consultancy. Margunato-Debay:Celgene Corporation: Employment, Equity Ownership. Czuczman:Celgene Corporation: Employment, Equity Ownership. Zhai:Celgene Corporation: Employment, Equity Ownership. Braverman:Celgene Corporation: Employment. Vitolo:Juno Therapeutics: 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; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; F. Hoffmann-La Roche: Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding.

Introduction : Daratumumab (DARA) is a human CD38 antibody approved in combination with standard-of-care (SoC) regimens in pts with NDMM who are TIE. DARA-based treatments showed significantly improved progression-free survival (PFS) in pts with TIE NDMM in ongoing phase 3 studies ALCYONE (DARA + bortezomib/melphalan/prednisone [D-VMP] vs VMP) and MAIA (DARA + lenalidomide/dexamethasone [D-Rd] vs Rd continuous). An NMA allows estimation of the relative efficacy of regimens not compared in head-to-head trials. A previous NMA examined D-VMP and D-Rd vs comparators (Facon T et al., EHA 2019), excluding the SWOG S0777 study (bortezomib/lenalidomide/dexamethasone [VRd]; Durie BG, et al. Lancet 2017) as it enrolled both transplant-eligible (TE) and TIE pts, and data for pts who are TIE only (~50% [aged ≥65 y and frail]) were unavailable. In this NMA, D-Rd and D-VMP had the highest probabilities of being more effective than reference treatment Rd continuous in terms of PFS. Recently, VRd received EMA approval for treatment of TIE NDMM based on SWOG S0777, but results specific to TIE pts are still unavailable. Recent NMAs of TIE pts (Blommestein HM et al., Haematologica, 2019; Weisel et al., EHA 2019; Cao Y et al., Clin Lymphoma Myeloma Leuk, 2019) have included data from the the intent-to-treat (ITT) population of SWOG S0777, though its inclusion violates the similarity assumption. Here, we present a sensitivity analysis of the previously-conducted NMA including all pts who received VRd in SWOG S0777 for a comprehensive view of the comparative effectiveness of DARA-based treatments in TIE NDMM. Methods: VRd was included as part of a sensitivity analysis of the previous NMA based on the ITT population, reporting PFS and overall survival (OS). The Guyot method was used to estimate OS hazard ratios (HRs) for pts aged ≥65 y (proxy for TIE) from SWOG S0777 (Durie BG et al., ASH 2018). Median follow-up in ALCYONE and MAIA was 27.8 months and 28.0 months, respectively. Based on a systematic literature review conducted through January 2019, both PFS and OS were extracted and synthesized in Bayesian NMAs. Choice of fixed- or random-effects (FE or RE) model was based on lowest deviance information criterion (DIC) and/or presence of heterogeneity in the network. Rd continuous was selected as reference, as it was commonly included in guidelines across regions. For PFS and OS, HR <1 indicates the comparison is not in favor of Rd continuous. In addition to the previous NMA, we also report an NMA sensitivity analysis including only comparators approved by the EMA that are relevant for the European, Middle East and/or Africa (EMEA) region (EMEA NMA). Results: Global NMA: RE model was used for both PFS and OS. Compared with Rd continuous, the PFS HR for VRd in the sensitivity analysis was 0.74 (95% credible interval [CrI], 0.42-1.30), which was similar to SWOG S0777 (0.71; [96% Wald confidence interval [CI], 0.56-0.91]) and higher than HRs for D-Rd (0.55; 95% CrI, 0.31-0.97) and D-VMP (0.58; 95% CrI, 0.20-1.62; Table). For OS, the SWOG S0777 HR estimated by Guyot algorithm for pts aged ≥65 y was 0.80 (95% CI, 0.56-1.16). Compared with Rd continuous, the OS HR for VRd in the sensitivity analysis was 0.80 (95% CrI, 0.51-1.26), which was similar to SWOG S0777 and higher than D-Rd (0.78; 95% CrI, 0.51-1.18). EMEA NMA: FE model was used for both PFS and OS. Compared with Rd continuous, the PFS HR for VRd in the sensitivity analysis was 0.74 (95% CrI, 0.60-0.92), which was higher than HRs of D-Rd (0.55; 95% CrI, 0.43-0.71) and D-VMP (0.64; 95% CrI, 0.41-1.02). Compared with Rd continuous, the OS HR for VRd in the sensitivity analysis was 0.80 (95% CrI, 0.55-1.17), which was higher than for D-Rd (0.78; 95% CrI, 0.56-1.09). These results are consistent with the Global NMA, but differ slightly as the EMEA NMA has fewer evidence-loops (only EMEA SoC regimens were included). Conclusions: This study demonstrated favorable efficacy outcomes for DARA-based regimens vs other relevant frontline options, such as VRd, for pts with NDMM who are TIE. Limitations of the sensitivity analysis include lack of comparative trial data and demographic differences between pts from SWOG S0777 and trials of frontline MM treatments for pts who are TIE included in our network. The majority of SWOG S0777 pts are TE (<65 y), who often have better prognoses than TIE pts (≥65 y), and thus violates the similarity assumption of NMAs. However, DARA-based regimens still showed a comparative clinical advantage. Disclosures Facon: Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. San-Miguel:Amgen, Bristol-Myers Squibb, Celgene, Janssen, MSD, Novartis, Roche, Sanofi, and Takeda: Consultancy, Honoraria. Usmani:Amgen, Bristol-Myers Squibb, Celgene, Janssen, Merck, SkylineDX, Takeda: Other: Consultant/Advisor; Amgen Array Biopharma, Bristol-Myers Squibb, Celgene, Janssen, Merck, Pharmacyclics, Sanofi, Takeda: Other: Research Grant; Amgen, Celgene, Janssen, Sanofi, Takeda: Speakers Bureau. Dimopoulos:Sanofi Oncology: Research Funding. Kumar:Janssen: Consultancy, Research Funding; Takeda: Research Funding; Celgene: Consultancy, Research Funding. Mateos:Adaptive: Honoraria; EDO: Membership on an entity's Board of Directors or advisory committees; Pharmamar: Membership on an entity's Board of Directors or advisory committees; Takeda: 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; GSK: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Cavo:Janssen, Celgene, Amgen, Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene, Janssen, Amgen, BMS, Abbvie, Takeda: Honoraria; Janssen, Celgene: Other: Travel Accommodations; Janssen, Celgene: Speakers Bureau. Heeg:Ingress-Health: Employment. Van Beekhuizen:Ingress-health: Consultancy. Pisini:Janssen: Employment, Equity Ownership. Nair:Janssen: Employment, Equity Ownership. Lam:Janssen: Employment, Equity Ownership. Slavcev:Janssen: Employment, Equity Ownership. He:Janssen: Employment, Equity Ownership.

Abstract Pathogenic sequence variants (PSV) in BRCA1 or BRCA2 (BRCA1/2) are associated with increased risk and severity of prostate cancer. We evaluated whether PSVs in BRCA1/2 were associated with risk of overall prostate cancer or high grade (Gleason 8+) prostate cancer using an international sample of 65 BRCA1 and 171 BRCA2 male PSV carriers with prostate cancer, and 3,388 BRCA1 and 2,880 BRCA2 male PSV carriers without prostate cancer. PSVs in the 3′ region of BRCA2 (c.7914+) were significantly associated with elevated risk of prostate cancer compared with reference bin c.1001-c.7913 [HR = 1.78; 95% confidence interval (CI), 1.25–2.52; P = 0.001], as well as elevated risk of Gleason 8+ prostate cancer (HR = 3.11; 95% CI, 1.63–5.95; P = 0.001). c.756-c.1000 was also associated with elevated prostate cancer risk (HR = 2.83; 95% CI, 1.71–4.68; P = 0.00004) and elevated risk of Gleason 8+ prostate cancer (HR = 4.95; 95% CI, 2.12–11.54; P = 0.0002). No genotype–phenotype associations were detected for PSVs in BRCA1. These results demonstrate that specific BRCA2 PSVs may be associated with elevated risk of developing aggressive prostate cancer. Significance: Aggressive prostate cancer risk in BRCA2 mutation carriers may vary according to the specific BRCA2 mutation inherited by the at-risk individual.

Abstract Objectives Smoking is a major risk factor for the development of both cardiovascular disease (CVD) and RA and may cause attenuated responses to anti-rheumatic treatments. Our aim was to compare disease activity, CVD risk factors and CVD event rates across smoking status in RA patients. Methods Disease characteristics, CVD risk factors and relevant medications were recorded in RA patients without prior CVD from 10 countries (Norway, UK, Netherlands, USA, Sweden, Greece, South Africa, Spain, Canada and Mexico). Information on CVD events was collected. Adjusted analysis of variance, logistic regression and Cox models were applied to compare RA disease activity (DAS28), CVD risk factors and event rates across categories of smoking status. Results Of the 3311 RA patients (1012 former, 887 current and 1412 never smokers), 235 experienced CVD events during a median follow-up of 3.5 years (interquartile range 2.5–6.1). At enrolment, current smokers were more likely to have moderate or high disease activity compared with former and never smokers (P &lt; 0.001 for both). There was a gradient of worsening CVD risk factor profiles (lipoproteins and blood pressure) from never to former to current smokers. Furthermore, former and never smokers had significantly lower CVD event rates compared with current smokers [hazard ratio 0.70 (95% CI 0.51, 0.95), P = 0.02 and 0.48 (0.34, 0.69), P &lt; 0.001, respectively]. The CVD event rates for former and never smokers were comparable. Conclusion Smoking cessation in patients with RA was associated with lower disease activity and improved lipid profiles and was a predictor of reduced rates of CVD events.

Abstract Introduction: Mutations localized in the tyrosine kinase domain activation loop of FLT3 (FLT3-TKD), representing point mutations in codon D835/I836 and rarely deletions of codon I836, induce constitutive tyrosine phosphorylation and activation of the receptor tyrosine kinase similarly to FLT3 internal tandem duplication (ITD) mutations. However, the prognostic role of FLT3-TKD in AML, particularly in the presence of NPM1 mutations, is not well established. The phase 3 RATIFY trial [NCT00651261; Stone et al. N Engl J Med. 2017] showed that in combination with standard chemotherapy, midostaurin (PKC412) improved survival outcomes across all 3 FLT3 stratification subgroups (ITD high allelic ratio [≥ 0.7], ITD low allelic ratio [< 0.7], and TKD) vs placebo in patients with newly diagnosed FLT3-mutated AML. Here, we evaluated the prognostic impact of FLT3-TKD and NPM1 mutations in a post hoc analysis from the RATIFY trial. Methods: In RATIFY, newly diagnosed patients with AML 18-60 years old were randomly assigned to receive midostaurin or placebo together with standard induction and consolidation therapy followed by 12 28-day cycles of maintenance therapy with midostaurin or placebo. FLT3-TKD mutation was detected by PCR and capillary electrophoresis at 9 reference laboratories. Patients were categorized as NPM1 mutated (mut) or NPM1 wild-type (WT) using PCR. Efficacy outcomes included complete remission (CR), overall survival (OS), event-free survival (EFS) and disease-free survival (DFS). EFS and DFS analyses were performed considering CR within a 60-day window. P values presented have not been adjusted for multiplicity. Results: Of the total randomized 162 FLT3-TKD patients, 134 with available NPM1 data had consented for exploratory analysis and thus were included in this study (see Table for subgroup distribution). Overall, 47.8% of patients were male, and the median age was 49 years (95% CI, 45.5-51.1 years). The median white blood cell (WBC) count was higher in patients with NPM1-mut than in patients with NPM1-WT (34.1 vs 15.5 × 109/L, P = .0011). CR rates (during the first 60 days) were higher in patients with FLT3-TKD/NPM1-mut vs FLT3-TKD/NPM1-WT (66% vs 53%); however, this was driven by the higher rate of CR in the midostaurin arm (76% NPM1-mut vs 44% NPM1-WT) rather than the placebo arm (53% NPM1-mut vs 60% NPM1-WT). The overall CR rate (regardless of NPM1 genotype) was 64% for midostaurin and 56% for placebo in FLT3-TKD patients. The prognostic effect of the NPM1 mutation concurrent with FLT3-TKD was seen for all endpoints consistently with hazard ratios (HRs) around 0.50 or lower (Figures 1 and 2 and Table). Overall (regardless of treatment) OS, EFS, and DFS estimates at 3 years were 73% vs 52%, 48% vs 25%, and 74% vs 47%, respectively, in patients with FLT3-TKD/NPM1-mut vs FLT3-TKD/NPM1-WT. Whereas the HRs for midostaurin vs placebo were 0.73 for both OS and EFS, the impact of treatment on outcomes varied between the individual NPM1/TKD subgroups and was not consistently observed when endpoints were censored at stem cell transplant (SCT) (Table). It should be noted that the number of patients in each subgroup was small and therefore the HRs with 95% CIs should be interpreted with caution. Multivariate analyses in these FLT3-TKD patients revealed that NPM1 genotype was an independent prognostic factor for OS, EFS and DFS (2-sided P < .05), whereas study drug, age, sex, WBC at baseline and SCT (no/yes) did not reach this level of significance in the Cox model. Conclusions: This post hoc analysis of the FLT3-TKD patient subset in the RATIFY trial showed the high prognostic value of NPM1 mutational status. Whereas midostaurin showed an overall benefit in the FLT3-TKD patients for OS, EFS, CR and DFS, the impact of treatment on outcome varied between the individual NPM1 subgroups within these FLT3-TKD patients and was not consistently observed.Further analyses using additional endpoints and additional multivariate analyses are planned. Support: U10CA180821, U10CA180882, U10CA180820, U10CA180791, U10CA180888, U10CA180863, (CCSRI) #704970, U24CA196171; ClinicalTrials.gov Identifier: NCT00651261 Disclosures Voso: Celgene: Research Funding, Speakers Bureau. Larson:Ariad/Takeda: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding. Heuser:Janssen: Consultancy; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; StemLine Therapeutics: Consultancy; Astellas: Research Funding; BergenBio: Research Funding; Karyopharm: Research Funding; Bayer Pharma AG: Consultancy, Research Funding; Tetralogic: Research Funding; Sunesis: Research Funding; Daiichi Sankyo: Research Funding. Wei:Novartis: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau; Pfizer: Honoraria, Other: Advisory committee; Amgen: Honoraria, Other: Advisory committee, Research Funding; Abbvie: Honoraria, Other: Advisory board, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Other: Advisory committee, Research Funding; Celgene: Honoraria, Other: Advisory committee, Research Funding. Brandwein:Lundbeck: Consultancy; Celgene: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Boehringer Ingelheim: Consultancy, Research Funding. de Witte:Novartis: Research Funding; Amgen: Consultancy, Research Funding; Celgene: Honoraria, Research Funding. Medeiros:Celgene: Consultancy, Research Funding; Genentech: Employment. Tallman:Cellerant: Research Funding; Orsenix: Other: Advisory board; BioSight: Other: Advisory board; ADC Therapeutics: Research Funding; AROG: Research Funding; AbbVie: Research Funding; Daiichi-Sankyo: Other: Advisory board. Schlenk:Pfizer: Research Funding, Speakers Bureau. Ganser:Novartis: Membership on an entity's Board of Directors or advisory committees. Cheng:Novartis: Employment. Gathmann:Novartis: Employment. Tiecke:Novartis: Employment. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding. Döhner:AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Sunesis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Celator: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Agios: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Pfizer: Research Funding; Pfizer: Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Stone:Otsuka: Consultancy; Argenx: Other: Data and Safety Monitoring Board; Amgen: Consultancy; Agios: Consultancy, Research Funding; Orsenix: Consultancy; Ono: Consultancy; Novartis: Consultancy, Research Funding; Astellas: Consultancy; Arog: Consultancy, Research Funding; Merck: Consultancy; Cornerstone: Consultancy; Fujifilm: Consultancy; Jazz: Consultancy; Celgene: Consultancy, Other: Data and Safety Monitoring Board, Steering Committee; Pfizer: Consultancy; Sumitomo: Consultancy; AbbVie: Consultancy.

Abstract Background Tipifarnib is a potent and selective inhibitor of the enzyme farnesyltransferase (FT). FT catalyzes post-translational attachment of farnesyl groups required for localization of signaling molecules to the inner cell membrane. CXCL12 is a chemokine that is essential for T cell homing to lymphoid organs and the bone marrow, and for the maintenance of immune cell progenitors. Herein we report preliminary efficacy, safety and biomarker data from a Phase 2 study of tipifarnib in angioimmunoblastic T-cell lymphoma (AITL) and CXCL12+ peripheral T-cell lymphoma (PTCL) patients (pts). Methods This Phase 2 study is a multi-institutional, single-arm, open-label trial initially designed as a two-stage (11+7 pts) cohort to determine the efficacy, safety and biomarkers of tipifarnib in pts with relapsed/refractory (R/R) PTCL, age >/=18 years and a performance status of 0-2. Based on initial findings, the study was amended to include a cohort of AITL (n=12) and PTCL (n=12) pts with the CXCL12 rs2839695 A/A genotype (CXCL12+ cohort). Pts received tipifarnib 300 mg administered orally twice daily on days 1-21 of 28-day treatment cycles until progression of disease (PD) or unacceptable toxicity. The primary endpoint of the study is overall response rate (ORR). Ancillary studies are also ongoing to investigate the prognostic value of CXCL12 expression in patients who received standard of care treatment. Results As of 25 July 2018, 34 PTCL pts (13 AITL, 1 ALK- ALCL, 20 PTCL-NOS) have been treated with tipifarnib, 19 pts in stages 1 and 2, and 15 pts in the ongoing AITL histology and CXCL12 cohorts. Median number of prior treatment regimens was 3. The most common treatment-related adverse events (AE) (grade ≥ 3) are hematological, including neutropenia (50%), thrombocytopenia (43%), leukopenia (33%), febrile neutropenia (27%), and anemia (20%). Skin and subcutaneous tissue disorders were reported in 9 pts, 6 of them with AITL histology. One pt with AITL experienced an episode of possible Stevens Johnson Syndrome that resolved with dose discontinuation and did not recur upon re-challenge at one dose level reduction. Of 18 evaluable patients enrolled in Stages 1 and 2 of the trial, 3 partial responses (PR), 2 of them in pts with AITL histology, and 4 best responses of stable disease (SD) were observed. Pre-treatment tumor tissue CXCL12 expression correlated with favorable pt outcomes. In the AITL cohort (10 evaluable pts), 1 PR and 1 SD have been observed so far, with 5 pts pending cycle 2 response evaluation. In the CXCL12+ cohort (n=3 evaluable pts), 1 SD has been observed, with 2 pts pending cycle 2 response evaluation. Plasma levels of CXCL12 decreased over time with tipifarnib treatment. Expression of CXCL12 mRNA and other biomarkers in pre-treatment biopsies of pts in the AITL and CXCL12+ cohorts are being evaluated using RT-PCR assays. In addition, the prognostic value of CXCL12 is being investigated in approximately 100 diagnostic specimens of PTCL pts who received standard therapy. Preliminary data suggest that CXCL12 overexpression is observed in approximately 25% of PTCL and negatively affects pt survival. Conclusion Preliminary activity of tipifarnib was observed in PTCL pts, particularly in those with tumors of AITL histology and high CXCL12 expression and enrollment continues. Disclosures Witzig: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Sokol:Mallinckrodt Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Spectrum Pharmaceuticals: Consultancy. Jacobsen:Merck: Consultancy; Seattle Genetics: Consultancy. Kim:Takeda: Research Funding; J&J: Research Funding; Mundipharma: Research Funding; Roche: Research Funding; Novartis: Research Funding; Kyowa-Kirin: Research Funding; Celltrion: Research Funding. Foss:Miragen: Consultancy, Speakers Bureau; Spectrum: Consultancy; Seattle genetics: Consultancy; Mallinkrodt: Consultancy. Advani:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kura: Research Funding; Merck: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Kyowa: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Regeneron: Research Funding; Janssen: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Cell Medica: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Autolus: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Gilead/Kite: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Research Funding; Agensys: Research Funding; Celgene: Research Funding; Forty Seven: Research Funding; Infinity: Research Funding. Marin Niebla:Amgen: Other: Medical education of Staff, Speakers Bureau; Roche: Consultancy, Other: Medical education of Staff, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Other: Medical education of Staff, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Medical education of Staff, Speakers Bureau. Piris:Kura: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Gilead: Honoraria. Curry:Kura Oncology: Employment, Equity Ownership. Gualberto:Kura Oncology: Employment, Equity Ownership.

Abstract Treatment of HL-60 human leukemia cells with etoposide induces apoptotic cell death and activation of at least 18 electrophoretically distinct cysteine-dependent aspartate-directed protease (caspase) isoforms, several of which differ only in their isoelectric points. The purpose of the present study was to determine whether activated caspases are phosphorylated. Phosphatase treatment of cytosolic extracts containing active caspases followed by affinity labeling with N-(N-benzyloxycarbonylglutamyl-N-biotinyllysyl)aspartic acid [(2,6-dimethylbenzoyl)oxy] methyl ketone (Z-EK(bio)D-aomk) showed a mobility shift in several of the labeled species, suggesting that phosphorylated forms of these enzymes are present in the extracts. Metabolic labeling with 32P followed by etoposide treatment and subsequent affinity purification of affinity-labeled caspases confirmed that at least three caspase species were phosphorylated. To detect effects of the phosphorylation on enzymatic activity, caspase-mediated cleavage of aspartylglutamylvalinylaspartyl-7-amino-4-trifluoromethylcoumarin (DEVD-AFC) and poly(ADP-ribose) polymerase (PARP) by phosphorylated and dephosphorylated extracts was measured. No significant changes in Km or vmax were detected using DEVD-AFC. In contrast, a slight, but significant enhancement of PARP cleavage was observed in dephosphorylated extracts, suggesting that phosphorylation of active caspases could have an inhibitory effect on enzyme activity. These observations, which provide the first evidence that caspases are phosphoproteins, suggest that caspases may be targets for some of the growing list of protein kinases that are involved in apoptotic events. © 1998 by The American Society of Hematology.