Devereux, Stephen

TPS8619 Background: Chemoimmunotherapy (CIT) treatment approaches such as FCR have markedly improved outcomes for CLL pts when administered as initial or second-line therapy. Despite this progress, virtually all pts relapse and effective salvage regimens that induce durable remissions or can be administered safely to elderly pts or those with comorbidities are lacking. BTK, an essential mediator of B-cell receptor signaling, is a novel target in CLL. Ibrutinib, a first-in class inhibitor of BTK, promotes apoptosis and inhibits proliferation, migration and adhesion in CLL cells. Phase II data of ibrutinib monotherapy in RR CLL demonstrated an estimated PFS and OS of 75% and 83% respectively at 26 months (Byrd Abst #189 ASH 2012). These findings confirmed BTK as an important target in CLL and supported initiation of a pivotal phase III study in pts with RR CLL/SLL. Methods: PCYC-1112-CA is an ongoing international Phase 3 randomized controlled study of ibrutinib versus ofatumumab for treatment of pts with RR CLL/SLL. The study is enrolling 350 planned pts in 9 countries. Pts are randomized 1:1 to receive ibrutinib 420 mg orally once daily or ofatumumab per the package insert at 300 mg for the first dose, then 2000 mg for a total of 12 doses over 24 weeks. Pts are stratified based on del 17p and disease refractory to purine analogs. Key inclusion criteria include RR CLL/SLL with >= 1 prior line of therapy including pts who experienced a short remission duration to purine analog based CIT, pts who are older or have comorbidities, and pts with del 17p. Pts must have active disease meeting criterion for requiring therapy and measurable nodal disease by CT. Key exclusion criteria include Richter’s transformation, stem cell transplantation within 6 months, GVHD or immunosuppression, platelet count <30,000 cells/ul or use of warfarin The primary objective of the study is PFS evaluated by an IRC. Other outcomes include ORR, OS, hematologic improvement, and safety. An independent DMC is monitoring the study. Clinical trial information: NCT01744691.

Abstract Background: Chronic lymphocytic leukemia (CLL) is primarily a disease of the elderly, with the majority of patients (pts) older than 65 y at diagnosis (US SEER). Historically, younger, more fit pts were eligible for aggressive chemoimmunotherapy treatments, but older age and comorbid conditions can limit options due to tolerability concerns. Ibrutinib (ibr), a first-in-class, oral, once-daily inhibitor of Bruton's tyrosine kinase, is indicated by the US FDA for the treatment of pts with CLL/small lymphocytic lymphoma (SLL) and allows for treatment without chemotherapy. Results from the phase 3 RESONATE (PCYC-1112) and RESONATE-2 (PCYC-1115) trials established ibr as a standard option in relapsed/refractory (R/R) and treatment-naïve (TN) CLL/SLL. This analysis examines safety and efficacy from these studies by age. Methods: RESONATE randomized 391 pts with R/R CLL/SLL to receive ibr (n=195; 420 mg once daily) until progressive disease (PD) or unacceptable toxicity or intravenous ofatumumab (n=196; 300 mg at week 1, 2000 mg weekly for 7 w and then every 4 w for 16 w). RESONATE-2 randomized TN pts aged ≥65 y to receive ibr (n=136; 420 mg once daily) until PD or chlorambucil (clb; n=133; 0.5 mg/kg to a maximum of 0.8 mg/kg) on days 1 and 15 of a 28-day cycle for up to 12 cycles. Pt data from both studies were grouped by age (ibr and comparators [comp]) and analyzed for effect of age on outcome. Results: Ibr group included 136 TN pts: 65 to <75 y (termed mid, n=90) and ≥75 y (termed old, n=46), and 195 R/R pts: <65 y (termed young, n=77), 65 to <75 y (mid, n=75), and ≥75 y (old, n=43). Table 1 lists key baseline pt characteristics. For ibr, median follow-up was 28.6 mo for TN and 36.1 mo for R/R pts. PFS is shown in Figure 1. For TN ibr pts, the 24-mo PFS rates were 88% (mid) and 89% (old), whereas clb pts aged ≥75 y did worse than those aged 65 to <75 y (23% vs 40%). For R/R pts, the 24-mo PFS was 75% (young), 77% (mid), and 62% (old). For ibr, median OS was not reached for any age subgroup (R/R or TN). The CR+CRi rates for TN ibr pts were 19% (mid) and 17% (old) and for R/R pts were 6% (young), 9% (mid), and 9% (old). Median treatment duration and the most common grade ≥3 AEs are listed in Table 2. The most frequent any-grade adverse events (AEs) were diarrhea, fatigue, cough, upper respiratory tract infection, nausea, pyrexia, and anemia for all pts and age subgroups. For ibr, grade ≥3 AEs occurred in 64% (mid) and 83% (old) of TN pts, and 70% (young), 84% (mid), and 84% (old) of R/R pts. The prevalence of common grade ≥3 AEs was typically highest in the first 12 mo of ibr therapy, and decreased thereafter for all age groups. Pts ≥75 y had a higher rate of grade ≥3 neutropenia and urinary tract infection in both TN and R/R populations. R/R ibr pts <65 y experienced a lower frequency of grade ≥3 pneumonia and atrial fibrillation (AF) than older subgroups. Any grade AF occurred in 11% (mid) and 9% (old) of TN ibr pts, and 1% (young), 20% (mid), and 14% (old) of R/R ibr pts. For ibr, dose reduction due to AE occurred in 9% (mid) and 22% (old) of TN pts and 6% (young), 20% (mid), and 12% (old) of R/R pts. 107 (79%) TN ibr pts remain on treatment: 81% (mid) and 74% (old); 99 (51%) R/R pts remain on treatment: 49% (young), 59% (mid), and 40% (old). For ibr, discontinuation due to AE occurred in 11% (mid) and 13% (old) of TN pts, and 6% (young), 11% (mid), and 19% (old) of R/R pts. The most common AE leading to discontinuation of ibr was infection(TN: n=4, RR: n=5). Conclusions: The PFS rate for TN ibr pts was similar regardless of age subgroup, whereas it was shorter for clb-treated pts ≥75 y compared with those 65 to <75 y. In the R/R population, ibr pts ≥75 y tended to have shorter PFS compared to those <75 y. There was no perceivable difference in CR rate by age within the TN and R/R ibr populations. The rates of grade ≥3 AEs tended to be higher in pts ≥75 y for both ibr and comp arms. Age did not impact discontinuation rates due to AE for TN pts treated with ibr, but increased with age for R/R pts. This study is limited by the number of pts ≤65 y who were only eligible for the R/R trial. This analysis supports single-agent ibrutinib as a treatment option regardless of pt age, but reinforces the need for close toxicity monitoring, especially in older pts. Disclosures Woyach: Karyopharm: Research Funding; Morphosys: Research Funding; Acerta: Research Funding. Hillmen:Pharmacyclics: Research Funding; Janssen: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Abbvie: Research Funding. Brown:Pfizer: Consultancy, Honoraria, Other: travel, accommodations, expenses; Genentech: Consultancy, Honoraria; Roche: Honoraria; Infinity: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Other: travel, accommodations, expenses; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: travel, accommodations, expenses; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria; Sun Biopharma: Honoraria, Other: travel, accommodations, or other expenses. Coutre:Pharmacyclics, LLC, an AbbVie Company: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; AbbVie: Research Funding. Barr:AbbVie: Consultancy; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Research Funding. O'Brien:Janssen: Consultancy, Honoraria; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding. Devereux:Janssen: Consultancy, Other: Travel, Accommodations, Expenses, Speakers Bureau; GSK: Consultancy; Roche: Consultancy, Other: Travel, Accommodations, Expenses ; Gilead: Consultancy, Other: Travel, Accommodations, Expenses, Speakers Bureau. Reddy:KITE: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; GILEAD: Membership on an entity's Board of Directors or advisory committees; INFINITY: Membership on an entity's Board of Directors or advisory committees. Mulligan:GSK: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau. Zhou:AbbVie: Equity Ownership; Pharmacyclics, LLC, an AbbVie Company: Employment. Ninomoto:AbbVie: Equity Ownership; Amgen: Equity Ownership; Pharmacyclics, LLC, an AbbVie Company: Employment. James:Pharmacyclics, LLC, an AbbVie Company: Employment; AbbVie: Equity Ownership. Burger:Janssen: Consultancy, Other: Travel, Accommodations, Expenses; Portola: Consultancy; Gilead: Research Funding; Pharmacyclics, LLC, an AbbVie Company: Research Funding; Roche: Other: Travel, Accommodations, Expenses.

Abstract Background: Patients (pts) with CLL/SLL who use unmutated IGHV (u-CLL) have a less favorable outcome with standard chemotherapy than pts who use mutated IGHV (m-CLL). Ibrutinib (ibr) inhibits B-cell receptor signaling through Bruton’s tyrosine kinase and has robust clinical activity against CLL. This integrated analysis of 3 phase 3 studies examined the impact of IGHV status on ibr- and comparator (comp)-treated pts. Methods: Pooled data from 3 studies of ibr (420 mg/d) in CLL/SLL pts (RESONATE: relapsed/refractory [R/R] pts, ibr vs ≤ 24 weeks ofatumumab; RESONATE-2: treatment-naïve [TN] pts ≥ 65 yrs of age [no del17p], ibr vs ≤ 12 cycles chlorambucil; HELIOS: R/R pts [no del17p], ≤ 6 cycles bendamustine-rituximab with ibr vs placebo) were analyzed by IGHV status. Analyses included Kaplan-Meier method (overall survival [OS]; progression-free survival [PFS]); log-rank test (group comparisons); and Cox multivariate analysis (prognostic factors; Table). Results: For 491 ibr- (366 u-CLL, 125 m-CLL) and 494 comp-treated (351 u-CLL, 143 m-CLL) pts with IGHV data, baseline characteristics were similar for u-CLL vs m-CLL, except for the proportions of pts who were TN (17 vs 31%), had bulky disease (60 vs 37%), or had CLL cells with del11q (32 vs 16%). Median follow up was 21.4 mos for ibr and 20.6 mos for comp. PFS and OS were similar for u-CLL and m-CLL ibr-treated pts; u-CLL had poorer outcomes than m-CLL in comp-treated pts, which remained after adjustment for prognostic factors (Table). Ibr treatment was more effective than comp regardless of IGHV status. Incidence of adverse events (AEs) was similar between groups. For ibr vs comp pts (u-CLL/m-CLL): serious AEs: 49% (50%/47%) vs 36.5% (37%/35%); AEs that led to discontinuation: 12% (11%/15%) vs 13% (13%/14%); death within 30 days of last dose: 5% (6%/3%) vs 5% (6%/2%). Conclusions: U-CLL was an adverse predictor of outcome for comp-treated, but not for ibr-treated pts. Table.Efficacy Outcomes in Ibr- and Comparator-Treated Patients by IGHV Mutation StatusIbrutinib (N=491)Comparator (N =494)u-CLL (n=717)m-CLL (n=268)u-CLL(n=366): m-CLL(n=125)u-CLL(n=351): m-CLL(n=143)Ibr(n=366): Comp(n=351)Ibr (n=125): Comp (n=143)PFS24-month rate HR78%:81%10%:32%78%:10%81%:32%0.93a1.99a0.12b0.21bp = 0.78p &lt; 0.0001p &lt; 0.0001p &lt;0.0001Adjusted HRc1.02a1.94a0.11b0.17bp = 0.93p &lt; 0.0001p &lt; 0.0001p &lt; 0.0001OS24-month rate HR88%:89%78%:87%88%:78%89%:87%0.95a1.96a0.49b0.85b,ep = 0.86p = 0.02p &lt; 0.01p = 0.66Adjusted HRc1.21a2.10a0.49bNAp =0.57p = 0.01p &lt; 0.001Response ratesu-CLLm-CLLu-CLLm-CLLIbrCompIbrCompORR, %d8990475189479051p = 0.96p = 0.36p &lt; 0.0001p &lt; 0.0001CR, %d221546224156p = 0.10p = 0.44p &lt; 0.0001p = 0.01CI, confidence interval; CR, complete response; HR, hazard ratio; ORR, overall response rate; NA, not applicable. aHR &lt; 1 favors unmutated. bHR &lt; 1 favors ibrutinib. cMultivariate Cox model adjusted for age, sex, current Rai stage, baseline ECOG performance status score, del11q, del17p, number of prior therapies, and cytopenias. dp value is from a Cochran-Mantel-Haenszel chi-square test. eInsufficient number of events prevents meaningful analysis, only 13 and 16 events observed in ibr and comp groups, respectively, and 46 (32%) pts in comp arm crossed over to ibr arm; interpret results with caution. Citation Format: Thomas J. Kipps, Graeme Fraser, Steven Coutre, Jennifer R. Brown, Jacqueline C. Barrientos, Paul M. Barr, John C. Byrd, Susan M. O'Brien, Marie-Sarah Dilhuydy, Stephen Devereux, Ulrich Jaeger, Carol Moreno, Paula Cramer, Stephan Stilgenbauer, Asher A. Chanan-Khan, Michelle Mahler, Mariya Salman, Mei Cheng, Anil Londhe, Joi Ninomoto, Angela Howes, Danelle James, Michael Hallek. Unmutated IGHV is not an adverse predictor of outcome to therapy with ibrutinib in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT158. doi:10.1158/1538-7445.AM2017-CT158