PURPOSE: Acalabrutinib, a highly selective, potent, Bruton tyrosine kinase inhibitor, was evaluated in this global, multicenter, randomized, open-label, phase III study in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL). METHODS: Eligible patients, aged ≥ 18 years with R/R CLL, were randomly assigned 1:1 centrally and stratified by del(17p) status, Eastern Cooperative Oncology Group performance status score, and number of prior lines of therapy. Patients received acalabrutinib monotherapy or investigator’s choice (idelalisib plus rituximab [I-R] or bendamustine plus rituximab [B-R]). The primary end point was progression-free survival (PFS) assessed by an independent review committee (IRC) in the intent-to-treat population. Key secondary end points included IRC-assessed overall response rate, overall survival, and safety. RESULTS: From February 21, 2017, to January 17, 2018, a total of 398 patients were assessed for eligibility; 310 patients were randomly assigned to acalabrutinib monotherapy (n = 155) or investigator’s choice (n = 155; I-R, n = 119; B-R, n = 36). Patients had received a median of two prior therapies (range, 1-10). After a median follow-up of 16.1 months (range, 0.03-22.4 months), median PFS was significantly longer with acalabrutinib monotherapy (PFS not reached) compared with investigator’s choice (16.5 months [95% CI, 14.0 to 17.1 months]; hazard ratio, 0.31 [95% CI, 0.20 to 0.49]; P < .0001). Estimated 12-month PFS was 88% (95% CI, 81% to 92%) for acalabrutinib and 68% (95% CI, 59% to 75%) for investigator’s choice. Serious adverse events occurred in 29% of patients (n = 44 of 154) treated with acalabrutinib monotherapy, 56% (n = 66 of 118) with I-R, and 26% (n = 9 of 35) with B-R. Deaths occurred in 10% (n = 15 of 154), 11% (n = 13 of 118), and 14% (n = 5 of 35) of patients receiving acalabrutinib monotherapy, I-R, and B-R, respectively. CONCLUSION: Acalabrutinib significantly improved PFS compared with I-R or B-R and has an acceptable safety profile in patients with R/R CLL.

Whether fixed-duration acalabrutinib-venetoclax (with or without obinutuzumab) would result in better progression-free survival than chemoimmunotherapy in patients with untreated chronic lymphocytic leukemia (CLL) is unknown. In this phase 3, open-label trial, we included patients 18 years of age or older who had an Eastern Cooperative Oncology Group performance-status score of 0 to 2 (range, 0 to 5, with higher numbers indicating greater disability) and who did not have a 17p deletion or TP53 mutation. Patients were randomly assigned, in a 1:1:1 ratio, to receive acalabrutinib-venetoclax (acalabrutinib, cycles 1 to 14; venetoclax, cycles 3 to 14), acalabrutinib-venetoclax-obinutuzumab (as above, plus obinutuzumab, cycles 2 to 7), or chemoimmunotherapy with the investigator's choice of fludarabine-cyclophosphamide-rituximab or bendamustine-rituximab (cycles 1 to 6). The primary end point was progression-free survival (acalabrutinib-venetoclax vs. chemoimmunotherapy) in the intention-to-treat population, assessed by blinded independent central review. A total of 867 patients underwent randomization: 291 were assigned to receive acalabrutinib-venetoclax, 286 acalabrutinib-venetoclax-obinutuzumab, and 290 chemoimmunotherapy (of whom 143 received fludarabine-cyclophosphamide-rituximab and 147 bendamustine-rituximab). The median age of the patients was 61 years (range, 26 to 86), 64.5% were men, and 58.6% had unmutated IGHV. Estimated 36-month progression-free survival at a median follow-up of 40.8 months was 76.5% with acalabrutinib-venetoclax, 83.1% with acalabrutinib-venetoclax-obinutuzumab, and 66.5% with chemoimmunotherapy (hazard ratio for disease progression or death with acalabrutinib-venetoclax vs. chemoimmunotherapy, 0.65 [95% confidence interval {CI}, 0.49 to 0.87], P = 0.004; for the comparison of acalabrutinib-venetoclax-obinutuzumab with chemoimmunotherapy, P<0.001). Estimated 36-month overall survival was 94.1% with acalabrutinib-venetoclax, 87.7% with acalabrutinib-venetoclax-obinutuzumab, and 85.9% with chemoimmunotherapy. Neutropenia, the most common adverse event of clinical interest of grade 3 or higher, was reported in 32.3%, 46.1%, and 43.2% in the three groups, respectively; death from coronavirus disease 2019 was reported in 10, 25, and 21 patients in the three groups. Acalabrutinib-venetoclax with or without obinutuzumab significantly prolonged progression-free survival as compared with chemoimmunotherapy in fit patients with previously untreated CLL. (Funded by AstraZeneca; AMPLIFY ClinicalTrials.gov number, NCT03836261.).

PURPOSE: Zanubrutinib is a potent, irreversible next-generation Bruton tyrosine kinase (BTK) inhibitor designed to maximize BTK occupancy and minimize off-target kinase inhibition. We hypothesized that complete/sustained BTK occupancy may improve efficacy outcomes and increased BTK specificity may minimize off-target inhibition-related toxicities. PATIENTS AND METHODS: ALPINE (ClinicalTrials.gov identifier: NCT03734016 ) is a global, randomized, open-label phase III study of zanubrutinib versus ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia. The primary end point was investigator-assessed overall response rate (ORR). The preplanned interim analysis was scheduled approximately 12 months after the first 415 patients were enrolled. RESULTS: Between November 1, 2018, and December 14, 2020, 652 patients were enrolled. We present the interim analysis of the first 415 enrolled patients randomly assigned to receive zanubrutinib (n = 207) or ibrutinib (n = 208). At 15 months of median follow-up, ORR (partial or complete response) was significantly higher with zanubrutinib (78.3%; 95% CI, 72.0 to 83.7) versus ibrutinib (62.5%; 95% CI, 55.5 to 69.1; two-sided P < .001). ORR was higher with zanubrutinib versus ibrutinib in subgroups with del(17p)/ TP53 mutations (80.5% v 50.0%) and del(11q) (83.6% v 69.1%); 12-month progression-free survival in all patients was higher with zanubrutinib (94.9%) versus ibrutinib (84.0%; hazard ratio, 0.40; 95% CI, 0.23 to 0.69). Atrial fibrillation rate was significantly lower with zanubrutinib versus ibrutinib (2.5% v 10.1%; two-sided P = .001). Rates of cardiac events, major hemorrhages, and adverse events leading to treatment discontinuation/death were lower with zanubrutinib. CONCLUSION: Zanubrutinib had a significantly higher ORR, lower atrial fibrillation rate, and improved progression-free survival and overall cardiac safety profile versus ibrutinib. These data support improved efficacy/safety outcomes with selective BTK inhibition.

The ALPINE trial established the superiority of zanubrutinib over ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia and small lymphocytic lymphoma; here, we present data from the final comparative analysis with extended follow-up. Overall, 652 patients received zanubrutinib (n = 327) or ibrutinib (n = 325). At an overall median follow-up of 42.5 months, progression-free survival benefit with zanubrutinib vs ibrutinib was sustained (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.54-0.84), including in patients with del(17p)/TP53 mutation (HR, 0.51; 95% CI, 0.33-0.78) and across multiple sensitivity analyses. Overall response rate remained higher with zanubrutinib compared with ibrutinib (85.6% vs 75.4%); responses deepened over time with complete response/complete response with incomplete bone marrow recovery rates of 11.6% (zanubrutinib) and 7.7% (ibrutinib). Although median overall survival has not been reached in either treatment group, fewer zanubrutinib patients have died than ibrutinib patients (HR, 0.77 [95% CI, 0.55-1.06]). With median exposure time of 41.2 and 37.8 months in zanubrutinib and ibrutinib arms, respectively, the most common nonhematologic adverse events included COVID-19–related infection (46.0% vs 33.3%), diarrhea (18.8% vs 25.6%), upper respiratory tract infection (29.3% vs 19.8%), and hypertension (27.2% vs 25.3%). Cardiac events were lower with zanubrutinib (25.9% vs 35.5%) despite similar rates of hypertension. Incidence of atrial fibrillation/flutter was lower with zanubrutinib vs ibrutinib (7.1% vs 17.0%); no cardiac deaths were reported with zanubrutinib vs 6 cardiac deaths with ibrutinib. This analysis, at 42.5 months median follow-up, demonstrates that zanubrutinib remains more efficacious than ibrutinib with an improved overall safety/tolerability profile. This trial was registered at www.ClinicalTrials.gov as #NCT03734016.