SOME PATIENTS WITH CLL SHOULD BE STARTED WITH IBRUTINIB

In patients with chronic lymphocytic leukemia (CLL), initial therapy with ibrutinib is among the factors that increase the likelihood of a complete response, according to pooled data from two trials.

Dr. Susan M. O’Brien of the University of California, Irvine, told Reuters Health by email, "Ibrutinib produces more complete (response) if given to people as initial therapy (as opposed to in relapse after prior therapy) and when they don’t have bulky disease."

Dr. O'Brien and colleagues analyzed data from 327 patients (median age, 67; 69.4% male) who had been treated with ibrutinib in the context of two clinical trials with follow-up lasting up to 55.6 months.

The new, pooled findings were reported online February 22 in JAMA Oncology.

Thirty-one patients (9.5%) received ibrutinib as first-line therapy and the rest had relapsed/refractory disease and had previously received a median of three therapies. In all, 185 patients (56.6%) had bulky disease (lymph node of at least 5 cm) and 184 (56.3%) had advanced-stage disease.

The response rate among all patients was 89.6%, and 32 patients (9.8%) achieved complete response. The median time to complete response was 14.7 months.

Multivariate analysis in the overall population showed that being treatment-naive significantly increased the likelihood of complete response (odds ratio, 2.65), compared to having had at least one previous therapy. Complete response also was significantly associated with not having bulky disease (OR, 4.97).

Among patients with relapsed/refractory disease, only having no bulky disease at baseline was significantly associated with achieving complete response (odds ratio, 4.18); being treatment-naive was not.

The researchers conclude, "The CR (complete response) rate with continued longer-term ibrutinib treatment was higher than in previous reports." Dr. O'Brien added, "Achieving CR raises the possibility of treatment discontinuation for patients."

Oncologist Dr. Jennifer A. Woyach of The Ohio State University, in Columbus, told Reuters Health by email, "These retrospective data, as well as the studies showing longer progression-free survival for those patients receiving ibrutinib as earlier lines of therapy, suggest that we should be using ibrutinib in the front-line setting rather than saving it for a salvage therapy."

Dr. Woyach, whose research interests include CLL, added that "there are many ongoing trials with the goal of discontinuing ibrutinib therapy, which would be great for patients in terms of both cost and side effects. If clinical trials show that we can safely discontinue ibrutinib in some patients who achieve a CR, data in this article would suggest that patients without bulky lymphadenopathy who are treated in the front-line setting might be those likely to be able to discontinue ibrutinib."

"However," she concluded, "it will be helpful to see these results validated in other studies that include more patients treated in the front-line setting."

SOURCE: http://bit.ly/2GKaNrY

JAMA Oncol 2018.