The results of a pooled analysis of patients with relapsed or refractory mantle cell lymphoma (MCL) treated with ibrutinib were presented at the 2017 American Society of Hematology (ASH) Annual Meeting & Exposition.

The extended follow-up data demonstrated that patients treated with ibrutinib earlier (after first relapse) experienced the best clinical outcomes in terms of both efficacy and tolerability.

“Data from this large clinical trial data set with extended follow-up support the early use of ibrutinib in patients with relapsed or refractory mantle cell lymphoma,” said Simon Rule, MD, Professor in Hematology at Plymouth University Medical School, United Kingdom, and lead investigator and presenter of the pooled analysis. “Long-term follow-up for ibrutinib demonstrates that in addition to efficacy, new-onset adverse events decrease over time and are generally less common when patients are treated earlier.”

The pooled analysis includes results from phase II and III studies (SPARK, PCYC-1104, and RAY; n = 370), and additional follow-up of 87 patients across these studies who enrolled in the long-term open-label extension study, CAN3001.

Eighty-three patients were treated with ibrutinib for 3 or more years, and 40 patients were treated with ibrutinib for 4 or more years.

With 3.5 years (41 months) of follow-up, the median progression-free survival overall was 13 months, and 33.6 months (range, 19.4–42.1 months) in patients with one prior line of therapy.

The median progression-free survival in patients achieving a complete response was 46.2 months (range, 42.1–not estimable), and the duration of response in these patients was 55.7 months (range, 55.7–not estimable).

Patients with favourable baseline disease characteristics were more likely to remain on ibrutinib for more than 3 years.

Overall, 53%, 45%, and 37% of patients were alive at 2, 3, and 5 years, respectively, and the median overall survival was 26.7 months.

Grade 3 or higher treatment-emergent adverse events occurred in 79.7% of patients, with the new-onset events decreasing after the first year.

New-onset grade 3/4 treatment-emergent adverse events were generally less common in patients who were treated earlier with ibrutinib.

In studies that permitted enrollment of patients with multiple cardiac risk factors, and among patients experiencing grade 3/4 atrial fibrillation, no patients discontinued treatment, and less than 1% had a dose reduction.

Source: ASCO