Ibrutinib dose modifications for management of cardiac adverse events in patients with B-cell malignancies: Pooled analysis of 10 clinical trials.

Abstract

7538 Background: Continuous therapy with once-daily ibrutinib (Ibr) is associated with long-term PFS in pts with B-cell malignancies. Dose reduction is a potential AE management approach that may optimize treatment outcomes. We evaluated outcomes with dose reductions in Ibr-treated pts with cardiac AEs. Methods: Data were pooled for Ibr-treated pts from 10 studies of CLL (n=781), mantle cell lymphoma (MCL; n=250), marginal zone lymphoma (MZL; n=63) or Waldenström macroglobulinemia (WM; n=169). Cardiac AEs, initial and recurrent, were identified by preferred terms within the cardiac disorders system organ class. Recurrence was defined as an AE of same or worse grade, and was measured up to 30 days after last dose of ibrutinib or start of next-line therapy, whichever occurred earlier. Results: Overall, 234/1263 pts (19%) had cardiac AEs of any grade. Twelve pts were excluded from the analysis: 9 who had a dose reduction prior to a cardiac AE (0.7%) and 3 who had a fatal cardiac AE with no prior cardiac AE (0.2%). Of the remaining 222 pts with grade 1-4 cardiac AEs, 22 (10%) had Ibr dose reduction to 420 mg (n=3), 280 mg (n=10), or 140 mg (n=9) after a cardiac AE. These pts (n=22) tended to be older (≥75 y: 45% vs 29%), less heavily pretreated (≥1 prior therapy: 45% vs 73%), and with a lower Ibr discontinuation rate (23% vs 48%) than those without dose reduction (n=200). Recurrence of the same cardiac AEs at the same or worse severity was less frequent in pts with dose reductions, both overall (14% vs 18%) and as serious AEs (5% vs 10%). No pt died due to cardiac AE recurrence. Among pts with cardiac AEs who started with the 420 mg Ibr dose (177/222; excludes 45 patients with MCL or MZL who per label start with 560 mg dose), no cardiac AE recurred at same or worse severity in the subset with dose reductions (Table). PFS was not negatively impacted by dose reduction, both overall (n=22; median PFS not reached [NR], 24-mo PFS: 91%), and in those who started with the 420 mg dose (n=18; median PFS NR; 24-mo PFS, 94%). Conclusions: Dose reduction for cardiac AEs may enable pts to continue to benefit from long-term Ibr and mitigate the risk of cardiac AE recurrence or worsening. Clinical trial information: NCT01105247 , NCT01236391 , NCT01578707 , NCT01722487 , NCT01611090 . [Table: see text]