A phase 3, open-label, randomized study of asciminib, a STAMP inhibitor, vs bosutinib in CML after 2 or more prior TKIs.

Patients with chronic myeloid leukemia in chronic phase (CML-CP) resistant/intolerant to ≥2 tyrosine kinase inhibitors (TKIs) are at high risk of experiencing poor outcomes because of disease biology and inadequate efficacy and/or safety of current therapies. Asciminib, a first-in-class BCR-ABL1 inhibitor Specifically Targeting the ABL Myristoyl Pocket (STAMP), has the potential to overcome resistance/intolerance to approved TKIs. In this phase 3, open-label study, patients with CML-CP previously treated with ≥2 TKIs were randomized (2:1) to receive asciminib 40 mg twice daily vs bosutinib 500 mg once daily. Randomization was stratified by major cytogenetic response (MCyR) status at baseline. The primary objective was to compare the major molecular response (MMR) rate at week 24 for asciminib vs bosutinib. A total of 233 patients were randomized to asciminib (n = 157) or bosutinib (n = 76). Median follow-up was 14.9 months. The MMR rate at week 24 was 25.5% with asciminib and 13.2% with bosutinib. The difference in MMR rate between treatment arms, after adjusting for MCyR at baseline, was 12.2% (95% confidence interval, 2.19-22.30; 2-sided P = .029). Fewer grade ≥3 adverse events (50.6% vs 60.5%) and adverse events leading to treatment discontinuation (5.8% vs 21.1%) occurred with asciminib than with bosutinib. The study showed a superior efficacy of asciminib compared with that of bosutinib, together with a favorable safety profile. These results support the use of asciminib as a new therapy in patients with CML-CP who are resistant/intolerant to ≥2 prior TKIs. This trial was registered at www.clinicaltrials.gov as #NCT03106779.

Asciminib vs bosutinib in chronic-phase chronic myeloid leukemia previously treated with at least two tyrosine kinase inhibitors: longer-term follow-up of ASCEMBL.

Asciminib, the first BCR::ABL1 inhibitor that Specifically Targets the ABL Myristoyl Pocket (STAMP), is approved worldwide for the treatment of adults with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (CML-CP) treated with ≥2 prior tyrosine kinase inhibitors (TKIs). In ASCEMBL, patients with CML-CP treated with ≥2 prior TKIs were randomized (stratified by baseline major cytogenetic response [MCyR]) 2:1 to asciminib 40 mg twice daily or bosutinib 500 mg once daily. Consistent with previously published primary analysis results, after a median follow-up of 2.3 years, asciminib continued to demonstrate superior efficacy and better safety and tolerability than bosutinib. The major molecular response (MMR) rate at week 96 (key secondary endpoint) was 37.6% with asciminib vs 15.8% with bosutinib; the MMR rate difference between the arms, after adjusting for baseline MCyR, was 21.7% (95% CI, 10.53-32.95; two-sided p = 0.001). Fewer grade ≥3 adverse events (AEs) (56.4% vs 68.4%) and AEs leading to treatment discontinuation (7.7% vs 26.3%) occurred with asciminib than with bosutinib. A higher proportion of patients on asciminib than bosutinib remained on treatment and continued to derive benefit over time, supporting asciminib as a standard of care for patients with CML-CP previously treated with ≥2 TKIs.

Durable treatment-free remission in patients with chronic myeloid leukemia in chronic phase following frontline nilotinib: 96-week update of the ENESTfreedom study.

PURPOSE: ENESTfreedom is evaluating treatment-free remission (TFR) following frontline nilotinib in patients with chronic myeloid leukemia (CML) in chronic phase. Following our primary analysis at 48 weeks, we here provide an updated 96-week analysis. METHODS: Attempting TFR required ≥ 3 years of nilotinib, a molecular response of MR4.5 [BCR-ABL1 ≤ 0.0032% on the International Scale (BCR-ABL1IS)], and sustained deep molecular response (DMR) during a 1-year consolidation phase. Patients restarted nilotinib following loss of major molecular response (MMR; BCR-ABL1IS ≤ 0.1%). RESULTS: Ninety-six weeks after stopping treatment (3.6-year median prior nilotinib duration), 93 of 190 patients (48.9%) remained in TFR. Of 88 patients who restarted nilotinib following loss of MMR, 87 regained MMR and 81 regained MR4.5 by the data cut-off. Ninety-six-week TFR rates were 61.3, 50.0, and 28.6% in patients with low, intermediate, and high Sokal risk scores at diagnosis, respectively. Patients consistently in MR4.5 during consolidation had higher TFR rates (50.6%) than patients with ≥ 1 assessment without MR4.5 during consolidation (35.0%). In a landmark analysis, 96-week TFR rates for patients with MR4.5, MR4 (BCR-ABL1IS ≤ 0.01%) but not MR4.5, and MMR but not MR4 at TFR week 12 were 82.6, 23.1, and 0%, respectively. There were no reports of disease progression or death due to CML; overall adverse event frequency decreased following TFR. Within the follow-up period, TFR did not adversely affect disease outcomes. CONCLUSIONS: These results demonstrate the feasibility and durability of TFR following frontline nilotinib and emphasize the importance of sustained DMR for TFR.

Effects of famotidine or an antacid preparation on the pharmacokinetics of nilotinib in healthy volunteers.

PURPOSE: This study evaluated the effects of either famotidine or antacid on the pharmacokinetics of nilotinib in healthy subjects, with the specific focus to explore different dosing separation schemes leading to a minimized drug-drug interaction. METHODS: Fifty-two subjects were randomized to receive the following treatments in a crossover manner: (A) single oral nilotinib 400 mg alone; (B) famotidine 20 mg twice a day for 3 days, followed by a single administration of nilotinib 400 mg and famotidine 20 mg on Day 4, where famotidine was given 2 h after nilotinib; (C) single oral nilotinib 400 mg and antacid suspension 20 mL, where antacid was given 2 h before nilotinib; (D) single oral nilotinib 400 mg and antacid suspension 20 mL, where antacid was given 2 h after nilotinib. RESULTS: Comparing Treatment B to Treatment A, the geometric mean ratios of nilotinib C(max), AUC(0-tlast), and AUC(0-inf) were 0.966, 0.984, and 0.911, respectively (90% confidence intervals (CIs), 0.875-1.066, 0.905-1.069, and 0.798-1.039, respectively). Nilotinib pharmacokinetic parameters following Treatment C or Treatment D were similar to those after Treatment A; the corresponding 90% CIs of the geometric mean ratios of C(max), AUC(0-tlast), and AUC(0-inf) all fell within the bioequivalence range of 0.8-1.25. CONCLUSIONS: Neither famotidine nor antacid significantly affected nilotinib pharmacokinetics. When concurrent use of an H2 blocker or an antacid is necessary, the H2 blocker may be administered 10 h before and 2 h after nilotinib dose, or the antacid may be administered 2 h before or 2 h after nilotinib dose.