Non Chemotherapy Combo Shows Efficacy Against Relapsed CLL

A small clinical trial has demonstrated that four of five patients with relapsed chronic lymphocytic leukemia (CLL) respond to a new therapy that does not involve chemotherapy.

The combination therapy included rituximab (Rituxan) and venetoclax (formerly ABT-199), an inhibitor of the anti-apoptosis protein B-cell lymphoma-2 (BCL-2).

A total of 41 out of 49 patients in the trial met the criteria for having experienced an objective response. Of those, nearly half had complete responses, meaning their disease was in remission afterwards.

The most frequently seen side effect was neutropenia.

Andrew W. Roberts, MD, of the Royal Melbourne Hospital in Australia, reported on the results at the European Hematology Association meeting taking place in Vienna.

"The combination of venetoclax and rituximab is a highly active, non-chemotherapy treatment for patients with relapsed and refractory CLL," he said. "The combination is well tolerated, as we observed no new toxicities as compared with venetoclax monotherapy. We observed minimum residual disease (MRD) in bone marrow in 24 of 49 patients, including 13 patients who achieved a complete response and MRD negativity.”

BCL-2 represents a major apoptosis escape mechanism for CLL-- in other words, BCL-2 allows the cancer cells to avoid programmed cell death. Venetoclax is believed to work by inhibiting BCL-2, which allows for the cell to undergo programmed cell death.

The patients in this trial had a median age of 68 and had a median treatment exposure of two prior therapies. Some patients had as many as five prior therapies.

Ultimately, there was an 84% overall response rate, including complete responses in 20 of 41 responding patients. Three of those 41 patients however have since relapsed.

Source: MedPage Today