Eckert, Karl

Abstract Background: Patients (pts) with deletion 17p (del17p) CLL follow an aggressive clinical course and experience poor outcomes with chemoimmunotherapy. Ibrutinib, an oral inhibitor of Bruton's tyrosine kinase (BTK), is approved for pts with CLL with ≥1 prior therapy and for pts with del17p CLL (including first-line). In the phase 2 RESONATE-17 study (PCYC-1117), ibrutinib demonstrated high efficacy with a favorable risk-benefit profile in del17p CLL/SLL (O'Brien, ASH 2014). We evaluate the baseline genetic features and prognostic factors of these pts to determine their impact on outcome. Methods: Pts with del17p CLL or SLL defined by peripheral blood FISH who failed ≥1 therapy received 420 mg oral ibrutinib once daily until progression or unacceptable toxicity. Using the primary analysis data cut, the overall response rate (ORR; iwCLL 2008 criteria by investigators), progression-free survival (PFS), and overall survival (OS) were assessed by subgroup. Results: Among 144 treated pts (137 CLL, 7 SLL), the median age was 64 (range 36-89). At baseline, 63% of pts had Rai stage III or IV disease, and 39% had received ≥3 prior therapies. Baseline cytogenetics included del11q (16%), del13q (74%), and trisomy 12 (17%), in addition to del17p in all pts. Of 116 pts with valid baseline genomic samples, IGHV status was unmutated in 84%; genomic variants that included mutations, rearrangements, insertions, deletions, and copy number variants affecting coding regions were identified as follows: ATM (14%), BIRC3 (3%), BTK (1%), MYC (2%), MYD88 (2%), NOTCH1 (16%), PLCG2 (3%), SF3B1 (27%), and TP53 (92%), which were consistent with previously identified mutations in pts with CLL (Wang, NEJM 2011; Winkelmann, Haematologica 2015). At a median follow-up of 11.5 months, the investigator-assessed ORR including partial response with lymphocytosis (PR-L) for all treated pts was 83% (17% PR-L). Median PFS and OS were not reached, with 12-month PFS and OS rates of 79% and 84%. Any-grade adverse events (≥15%) included diarrhea (36%), fatigue (31%), cough (24%), arthralgia (22%), nausea (19%), hypertension (19%), anemia (19%), pyrexia (17%), decreased appetite (17%), muscle spasms (17%), neutropenia (17%), and peripheral edema (15%). Serious AEs occurred in 40% of pts (38% ≥ grade 3). ORR, 12-month PFS, and 12-month OS are presented by subgroup for baseline characteristics, cytogenetics, and genomic variants (Table). There were no substantial differences in response rates and survival outcomes in the subgroups with and without baseline cytogenetic aberrations or genomic variants (Table). Response rates were similar for pts with and without NOTCH1 or SF3B1 variants. Of 11 pts with del17p CLL who developed Richter transformation, baseline aberrations included ATM (n=2), SF3B1 (n=3), and/or NOTCH1 (n=3); none had BIRC3 variants. Overall at baseline, there were 3 pts with a PLCG2 mutation (L163F, H193Q, P236L), and 1 with a BTK mutation (R236Q); all achieved a best overall response of PR-L or better. None had received prior therapy with a BTK or PI3K inhibitor. Two pts had a baseline MYD88 mutation (L265P, L142F) with a best overall response of PR in 1 pt. Two pts had baseline MYC amplifications with 5 of 5 exons amplified to 6 and 7 copies, respectively; 1 pt achieved a best overall response of PR. Conclusions: These results provide further evidence of ibrutinib's robust clinical activity and encouraging survival outcomes in this high-risk population regardless of baseline cytogenetic aberrations or genomic variants. The prognostic role of these clinical characteristics and genetic anomalies will continue to be elucidated with longer term follow-up of this population. Figure 1. Investigator-assessed efficacy outcomes by subgroups Figure 1. Investigator-assessed efficacy outcomes by subgroups Disclosures Stilgenbauer: AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Jones:Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding. Coutre:AbbVie: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mato:Celgene: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; TA Therapeutics: Research Funding; Gilead: Consultancy, Other: Travel, Accommodations, Expenses; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: Travel, Accommodations, Expenses. Hillmen:AbbVie: Honoraria, Research Funding; Roche Pharmaceuticals: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria, Research Funding; Gilead: Honoraria, Research Funding. Tam:Janssen: Consultancy, Honoraria, Research Funding. Osterborg:Gilead: Honoraria; Janssen: Honoraria, Research Funding; GSK: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Amgen: Research Funding. Siddiqi:Pharmacyclics: Research Funding, Speakers Bureau; Janssen: Speakers Bureau. Thirman:Gilead: Research Funding; Merck: Research Funding; AbbVie: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding. Furman:Gilead: Consultancy; Acerta Pharma BV: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Speakers Bureau. Li:Pharmacyclics LLC, an AbbVie Company: Employment. Eckert:Pharmacyclics LLC, an AbbVie Company: Employment. Chang:Pharmacyclics LLC, an AbbVie Company: Employment. James:Pharmacyclics LLC, an AbbVie Company: Employment. Chu:Pharmacyclics LLC, an AbbVie Company: Employment. Hallek:Pharmacyclics LLC, an AbbVie Company: Consultancy, Speakers Bureau; Janssen: Speakers Bureau. O'Brien:Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding.

Abstract Introduction: Ibrutinib (Imbruvica®), an oral, first-in-class covalent BTK inhibitor, is a new treatment option approved by FDA for chronic lymphocytic leukemia (CLL) patients (pts) with ≥1 prior therapy. We previously reported results from the phase III trial, in which ibrutinib (ibr) significantly improved progression-free and overall survival vs ofatumumab (ofa) in pts with relapsed/refractory CLL or small lymphocytic lymphoma (SLL) (Byrd et al. NEJM, 2014). Here, we report measures of patient well-being, including hematologic, immunologic, and quality of-life parameters, at interim analysis (IA). Methods: Pts with CLL/SLL after ≥1 prior therapy were randomized 1:1 to ibr 420 mg/day until progression or unacceptable toxicity, or to ofa for up to 24 weeks. At IA, secondary efficacy endpoints of hematologic improvement (sustained improvement ≥56 days without transfusions or growth factors) and FACiT-Fatigue (FACiT-F) outcomes were analyzed, along with exploratory endpoints assessing disease-related symptoms (DRS), serum immunoglobulin, patient-reported outcomes (PROs) by EORTC QLQ-C30, and medical resource utilization (MRU). Results: Of 391 enrolled pts (ibr n=195; ofa n=196), 63% had cytopenia(s) at baseline: 45% had anemia (hemoglobin ≤11 g/dL), 35% thrombocytopenia (platelets ≤100×109/L), and 20% neutropenia (absolute neutrophil counts [ANC] ≤1.5×109/L). On the ibr arm, 69% of pts with baseline cytopenias experienced sustained improvement in blood counts compared to 43% on ofa (P<0.0001, table). There was no decrement in serum immunoglobulins (IgA, IgG, IgM) during follow-up. IgA levels increased on the ibrutinib arm only (mean change from baseline: 41% at week 24). Immune cells CD4+ and CD8+ T-cell and NK-cell levels remained relatively stable during treatment. Mean change in FACiT-F score from baseline are shown in the figure for ibr and ofa arms. At week 24, clinically meaningful (≥3 points) improvement in FACiT-F occurred in more pts on ibr than ofa (59% vs 46%, P=0.06); clinically meaningful deterioration was reported by 14% vs 24% (P=0.08), respectively. A larger proportion of ibr vs ofa pts showed clinically meaningful improvement on EORTC-QLQ-C30 global health scores (46% vs 40%). Clinically meaningful improvement (≥10 points) from baseline to week 24 in ibr vs ofa pts was observed for fatigue (median 11 vs 0). A 50% reduction in lymph node based on IRC-assessed CT was observed in 93% (177/190 evaluable) of ibr pts compared with 17% (29/174 evaluable) of ofa pts (P< 0.0001). Splenic response based on IRC-assessed CT was reported for 85% (138/163 evaluable) of ibr pts compared with 54% (82/151 evaluable) of ofa pts. Baseline DRS were comparable between groups; however, improvement by at least 1 grade (G) post-baseline was observed in ibr relative to ofa pts for weight loss (100% vs 93%), fatigue (88% vs 72%), night sweats (95% vs 86%), and anorexia (100% vs 64%), respectively. Cumulative MRU was comparable for growth factors and transfusions, with ibr pts having longer median treatment duration: 8.6 months for ibr vs 5.3 for ofa. Hospitalizations in the first 30 days occurred in 2% ibr vs 15% ofa pts. After adjusting for treatment exposure duration, diarrhea, grade 1-2 bleeding events (e.g petechiae), and atrial fibrillation were among those noted to be more frequent on the ibrutinib arm while events such as fatigue, infusion reaction, and peripheral sensory neuropathy were seen more commonly with ofa. Major hemorrhage events were uncommon, observed in 2 patients on the ibr arm vs 3 on ofa arm without adjusting for exposure time. Exposure-adjusted analysis showed no difference in any-grade infection and a 43% relative reduction for grade 3 or higher infections for ibr. Conclusions: Ibr compared to ofa when administered to previously treated CLL/SLL pts led to improvements in hematologic function and disease burden. A survival benefit with ibr, together with sustained improvements in hematologic endpoints and PRO suggest that ibr enhances quality of life while prolonging survival. Table. Sustained hematologic improvement Parameter, n (%) ITT population Pts with cytopenias at baseline Ibr n=195 Ofa n=196 P value Ibr n=195 Ofa n=196 P value Platelets 60 (31) 19 (10) <0.0001 53/74 (72) 14/64 (22) <0.0001 ANC 52 (27) 19 (10) <0.0001 26/41 (63) 12/38 (32) 0.0047 Hemoglobin 42 (22) 32 (16) 0.1883 42/89 (47) 32/86 (37) 0.1815 Figure. Improvement in FACiT-F by treatment arm. Figure. Improvement in FACiT-F by treatment arm. Disclosures Barrientos: Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding. Brown:Sanofi, Onyx, Vertex, Novartis, Boehringer, GSK, Roche/Genentech, Emergent, Morphosys, Celgene, Janssen, Pharmacyclics, Gilead: Consultancy. Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees. Coutre:Janssen, Pharmacyclics: Honoraria, Research Funding. Tam:Pharmacyclics and Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Mulligan:Roche, Abbvie: Consultancy, Honoraria. Jaeger:Janssen Cilag: Honoraria. Devereux:Pharmacyclics, Janssen: Consultancy, Honoraria. Robak:Janssen: Consultancy, Research Funding. Schuh:Roche, Gilead, GSK, NAPP, Celgene: Honoraria. Bloor:GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Dearden:Roche, GSK, Gilead, Janssen, Napp: Honoraria. Jones:Pharmacyclics: Consultancy, Research Funding. Kierschniak:Pharmacyclics, GmbH: Employment. Eckert:Pharmacyclics: Employment. Suzuki:Pharmacyclics: Employment. Hsu:Pharmacyclics: Employment. James:Pharmacyclics: Employment. Byrd:Pharmacyclics: Research Funding. Hillmen:Pharmacyclics, Janssen, Gilead, Roche: Honoraria, Research Funding.