Pristupa, Aleksander

Abstract Introduction Ibrutinib has become a new standard of care in patients with previously treated CLL/SLL based on the phase 3 RESONATE study (Byrd, et al. NEJM 2014) and other trials evaluating ibrutinib mainly as a single agent in CLL. The first randomized, double-blind, placebo-controlled phase 3 study (HELIOS) investigating ibrutinib in combination with bendamustine and rituximab (BR) was recently reported (Chanan-Khan, et al. ASCO 2015), with ibrutinib significantly extending progression-free survival and reducing the risk of progression/death by 80%. The study design provides an opportunity to examine the overall safety and management of adverse events (AEs) with ibrutinib and placebo in a blinded manner that previously has not been possible. Here we examine the safety and management of AEs with ibrutinib + BR vs placebo + BR in HELIOS. Methods Patients with active CLL/SLL following ≥ 1 prior line of systemic therapy were randomized 1:1 to receive BR (≤ 6 cycles) with either ibrutinib 420 mg daily or placebo (n = 289 in each group). Safety was a secondary end point. Results Median exposure to ibrutinib and placebo was 14.7 and 12.8 months, respectively. Rates of infection in the ibrutinib + BR and placebo + BR arms were similar (all-grade, 70.4%; grade ≥ 3, 26.8% vs all-grade, 70.0%; grade ≥ 3, 22.6%, respectively) but exposure-adjusted analysis reveals an overall lower rate of infections with ibrutinib + BR vs placebo + BR (10.3/100 vs 11.2/100 patient-months), with similar rates of grade ≥ 3 infections (2.4/100 patient-months each arm). Rates of all-grade (grade 3/4) anemia were 22.3% (3.5%) with ibrutinib + BR and 28.9% (8.0%) with placebo + BR. Patients also required fewer transfusions with ibrutinib + BR (23%) vs placebo + BR (29%), the majority of which were red blood cell transfusions. Similar proportions of patients used growth factors in both arms (54% vs 52%, respectively). Grade 3/4 neutropenia was reported at similar rates in both arms (53.7% vs 50.5%, respectively); however, fewer patients discontinued due to treatment-related neutropenia with ibrutinib + BR (1.0%) vs placebo + BR (2.8%). Rates of thrombocytopenia were slightly higher with ibrutinib + BR (30.7%) than placebo + BR (24.0%), but rates of grade 3/4 events were similar between arms (15.0% each arm). Atrial fibrillation (AF) was observed more frequently in patients on ibrutinib + BR than placebo + BR (7.3% vs 2.8% overall and 2.8% vs 0.7% grade 3/4, respectively). However, only 4 patients with grade 3/4 AF discontinued therapy in the ibrutinib arm. No patients with grade 1/2 AF discontinued treatment. One-third of patients held ibrutinib treatment to manage AF, with all restarting at the same dose (420 mg). Median (range) time to onset was 3.0 (0.3-17.5) months with ibrutinib + BR and 2.4 (0.6-18.9) months with placebo + BR. Importantly, in those with a prior history of AF or abnormal heart rhythm, only 7/25 receiving ibrutinib + BR and 2/22 receiving placebo + BR developed AF/atrial flutter on study. The rates of any-grade bleeding were 31.0% and 14.6%, respectively, with the majority being grade 1 (77.5% and 69.0%, respectively). Low rates of grade 3/4 major bleeding were observed in the ibrutinib + BR (2.1%) and placebo + BR (1.7%) arms. Many patients (41.8% ibrutinib + BR, 41.1% placebo + BR) were receiving concomitant anticoagulant/antiplatelet medication. A low rate of treatment-related lymphocytosis was observed in both arms (7.0% ibrutinib + BR, 5.9% placebo + BR). The majority of cases resolved within 2 weeks. Conclusions In this randomized, double-blind, placebo-controlled trial, the addition of ibrutinib to BR was well tolerated and did not significantly impact the safety profile of BR. In addition, ibrutinib was associated with reduced rates of anemia and transfusional support. Consistent with its known toxicity profile, patients in the ibrutinib + BR arm had higher rates of bleeding (mostly grade 1 or 2) and AF; however, few patients discontinued therapy as a result of these AEs. A prior history of AF or abnormal heart rhythm did not lead to recurrent episodes in the majority of cases. Taken together, the results from HELIOS establish the significant efficacy of ibrutinib and also the overall positive risk-benefit profile of ibrutinib + BR. Disclosures Cramer: Janssen: Other: Travel grant, Research Funding, Speakers Bureau; Hoffman LaRoche: Other: Travel grant, Research Funding, Speakers Bureau; Astellas: Other: Travel grant; Glaxo Smith Klein/Novartis: Research Funding; Gilead: Other: Travel grant, Research Funding; Mundipharma: Other: Travel grant. Demirkan:Celgene: Other: Travel reimbursement; Amgen: Consultancy. Fraser:Hoffman LaRoche: Consultancy, Honoraria; Janssen: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding. Santucci Silva:Janssen: Other: Travel reimbursement, Research Funding; GSK: Research Funding; Celgene: Research Funding; Merck: Research Funding; Novartis: Other: Travel reimbursement; Hoffman LaRoche: Other: Travel reimbursement, Research Funding. Janssens:Roche: Consultancy, Speakers Bureau; Mundipharma: Speakers Bureau; Janssen: Consultancy. Goy:Allos, Biogen Idec, Celgene, Genentech, and Millennium. Gilead: Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Mayer:Janssen: Research Funding. Dilhuydy:Roche: Honoraria, Other: Travel reimbursement; Janssen: Honoraria, Other: Travel reimbursement; Mundipharma: Honoraria. Bartlett:Medimmune: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Genentech: Research Funding; ImaginAB: Research Funding; Astra Zeneca: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Gilead: Consultancy; Seattle Genetics: Consultancy, Research Funding; Millenium: Research Funding; Celgene: Research Funding. Rule:Roche: Consultancy, Other: Travel reimbursement; Gilead: Research Funding; Celgene: Consultancy, Other: Travel reimbursement; J&J: Consultancy, Other: Travel reimbursement, Research Funding. Sun:Janssen/J&J: Employment, Equity Ownership. Phelps:Janssen/J&J: Employment, Equity Ownership. Mahler:Janssen: Employment, Other: Travel reimbursement. Salman:Janssen/J&J: Employment, Equity Ownership. Howes:Janssen/J&J: Employment, Equity Ownership. Hallek:AbbVie: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Roche: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Gilead: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Pharmacyclics: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Celgene: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Boehringher Ingelheim: Honoraria, Other: Speakers Bureau and/or Advisory Boards; Mundipharma: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Janssen: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding.

Abstract Introduction Ibrutinib is a first-in-class, once-daily, oral, covalent inhibitor of BTK that has excellent single-agent activity in patients with previously treated CLL/SLL, based on results of published clinical studies. In the HELIOS trial, addition of ibrutinib to BR resulted in an 80% reduction in disease progression or death and confirmed for the first time, in a randomized setting, the benefit of ibrutinib-based therapy compared with standard chemoimmunotherapy (CIT) in previously treated patients (Chanan-Khan et al. ASCO 2015). In patients with CLL or SLL, deletion 17p (del17p) and 11q (del11q), complex karyotype, unmutated IgVH, and elevated ZAP70 are known high-risk prognostic factors. The current analysis reports on the efficacy of ibrutinib + BR vs placebo + BR in patients in the HELIOS trial with relevant high-risk biomarkers. Methods HELIOS is a randomized, double-blind, placebo-controlled, phase 3 study. Patients with active CLL/SLL following ≥ 1 prior therapy were randomized 1:1 to receive BR (≤ 6 cycles) with either ibrutinib (420 mg daily) (n = 289) or placebo (n = 289). Patients with del17p (> 20% of cells) were excluded. Ninety patients in the placebo arm with independent review committee (IRC)-confirmed progressive disease crossed over to ibrutinib, per protocol amendment. The primary end point was IRC-assessed progression-free survival (PFS), and overall survival (OS) was a secondary end point. A total of 287 patients in each arm had data available for at least 1 biomarker, and this population was used for the biomarker analyses. Correlation of biological risk factors at baseline with PFS and OS was analyzed using Kaplan-Meier analysis and curves compared using log-rank tests. Hazard ratios (HRs) were estimated using univariate Cox proportional hazards models. Results At a median follow-up of 17 months, IRC-assessed PFS was significantly longer with ibrutinib + BR vs placebo + BR in the overall study population (median not reached vs 13.3 months, respectively; HR: 0.203; 95% CI: 0.150-0.276; p < 0.0001). All subgroups of patients, including those with adverse prognostic parameters, e.g., del11q, complex karyotype, unmutated IgVH and elevated ZAP70 levels, had a significantly longer PFS with the addition of ibrutinib to BR as compared with placebo + BR (Table 1). As expected, each of these adverse prognostic parameters had a negative impact on PFS in the placebo + BR arm, e.g., the median PFS was shortest in patients with complex karyotype [8.5 months vs 13.8 months in patients without complex karyotype] and in patients with unmutated IgVH (11.3 months vs 22.1 months in patients with mutated IgVH). Interestingly, in the ibrutinib + BR arm, the adverse impact of these risk factors could not be detected (median PFS not reached irrespective of presence of risk factors). For example, in Figure 1 showing the PFS curves stratified by both del11q status and treatment, the outcome for patients in the ibrutinib + BR arm with del11q was similar to those without, with a trend toward better outcome in the del11q patients (e.g., longer PFS - not reached vs 24.9 months), unlike for patients in the placebo + BR arm (11.01 months vs 13.86 months). In patients with del11q, unmutated IgVH, or elevated ZAP70, there were also statistically significant benefits in OS for those receiving ibrutinib + BR vs placebo + BR (del11q: HR: 0.326, 95% confidence interval [CI], 0.122-0.870; p = 0.025; unmutated IgVH: HR: 0.515, 95% CI, 0.298-0.890: p = 0.017; elevated ZAP70, HR 0.536, 95% CI, 0.289-0.994: p = 0.048). Addition of ibrutinib also increased PFS in patient subgroups with other cytogenetic or clinical prognostic markers (such as del13q or bulky disease) compared with placebo. Conclusions All subgroups of patients, irrespective of adverse risk factors, such as del11q, complex karyotype, elevated ZAP70, and unmutated IgVH, benefit from the addition of ibrutinib to BR compared with placebo + BR. The negative impact of these known risk factors is apparent in patients in the placebo + BR arm, but is not seen in patients in the ibrutinib + BR arm. These results suggest that ibrutinib + BR is a suitable treatment regimen for all patients with previously treated CLL/SLL, including those with high-risk prognostic markers. Disclosures Cramer: Janssen: Other: Travel grant, Research Funding, Speakers Bureau; Hoffman LaRoche: Other: Travel grant, Research Funding, Speakers Bureau; Mundipharma: Other: Travel grant; Glaxo Smith Klein/Novartis: Research Funding; Astellas: Other: Travel grant; Gilead: Other: Travel grant, Research Funding. Fraser:Janssen: Honoraria, Research Funding, Speakers Bureau; Hoffman LaRoche: Consultancy, Honoraria; Celgene: Honoraria, Research Funding. Santucci Silva:Janssen: Other: Travel reimbursement, Research Funding; GSK: Research Funding; Celgene: Research Funding; Merck: Research Funding; Novartis: Other: Travel reimbursement; Hoffman LaRoche: Other: Travel reimbursement, Research Funding. Dilhuydy:Roche: Honoraria, Other: Travel reimbursement; Janssen: Honoraria, Other: Travel reimbursement; Mundipharma: Honoraria. Goy:Allos, Biogen Idec, Celgene, Genentech, and Millennium. Gilead: Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Mato:Celgene: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Gilead: Consultancy, Other: Travel, Accommodations, Expenses; Pharmacyclics LLC, an AbbVie Company: Consultancy, Other: Travel, Accommodations, Expenses; TA Therapeutics: Research Funding. Damle:Janssen: Employment. Phelps:Janssen/J&J: Employment, Equity Ownership. Mahler:Janssen: Employment, Other: Travel reimbursement. Salman:Janssen/J&J: Employment, Equity Ownership. Schaffer:Janssen: Employment. Howes:Janssen/J&J: Employment, Equity Ownership. Balasubramanian:Pharmacyclics LLC, an AbbVie Company: Equity Ownership; Janssen: Employment, Equity Ownership.