Lenalidomide in Adult ATL Shows Further Promise

Use of lenalidomide monotherapy in patients with adult T-cell leukemia/lymphoma (ATL) resulted in clinically meaningful antitumor activity, with 42% of phase II trial participants having objective responses.

Based on these trial results, published in the Journal of Clinical Oncology, Takashi Ishida, MD, PhD, of Nagoya City University Graduate School of Medical Sciences, Japan, and colleagues said that lenalidomide monotherapy has “potential to become a treatment option in this patient population.”

The phase II study included 26 patients aged 20 or older with acute, lymphoma, or unfavorable chronic subtype ATL. All patients had received at least one prior anti-ATL therapy and achieved stable disease or better, but had subsequent relapse or recurrence. The median age of patients was 68.5 years.

All patients received oral lenalidomide 25 mg per day until disease progression or unacceptable toxicity. The primary endpoint was overall response.

At a median of 3.9 months follow-up, 11 of 26 patients (42%) had an objective response including 4 patients that had complete responses (15%). Responses occurred in 33% of patients with acute, 57% of patients with lymphoma, and 50% of patients with unfavorable ATL. The tumor control rate was 73%.

The most commonly occurring grade 3 or worse adverse event was neutropenia (65%). Other common adverse events included leukopenia (38%), lymphopenia (38%), and thrombocytopenia (23%).

In an unplanned ad hoc analysis, the researchers found objective responses in 8 of 13 patients (62%) with adverse events of grade 2 or higher, including 2 complete responses and 1 unconfirmed complete response. Objective responses in patients who had grade 1 or no adverse events were found in 3 of 13 patients (23%). Adverse events were classified under the Medical Dictionary for Regulatory Activities system organ class of skin and subcutaneous tissue disorders.

Median time to response was 1.9 months; median duration of response was not estimable. The median time to progression was 3.8 months, and the median overall survival was 20.3 months.

In their discussion of the results, the researchers acknowledged that the sample size of the study was small and included patients with three subtypes of ATL. In addition, patients prior treatments could also have affected results. “On the basis of these promising results, further investigations of lenalidomide in ATL and other T-cell neoplasms are warranted,” they wrote.