New Compound Strong Against CLL / SLL

New research has found a potentially effective treatment target for patients with chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL).

Since B-cell cancers like CLL/SLL are often related to problems with B-cell lymphoma-2 (BCL-2) proteins, researchers from Australia, presenting at the recent American Society of Hematology conference in New Orleans, developed a new compound designed to trigger the cell death that BCL-2 proteins are preventing.

It is believe that the compound, known as ABT-199, can cause the cells to die like they’re supposed to. In order to test whether this was as true in people as it had been in the lab, researchers recruited 56 patients with relapsed or treatment-resistant CLL or SLL into a Phase I study designed to test the safety and maximum tolerable dosage.

Early results demonstrated anti-tumor activity: among participants, there was an 84 percent overall response rate, and further, a 21 percent complete response rate.

Said John Seymour, MBBS, PhD, of the Peter MacCallum Cancer Centre in Melbourne, Australia:

We are very encouraged by these early results and in particular, by the high rate of complete response among patients with treatment-resistant or relapsed CLL. Our ongoing work will seek to improve the efficacy of this drug while carefully monitoring toxicities to deliver the maximum benefit to high-risk patients where conventional chemotherapy has proven inadequate.

In what is a potentially good sign, early on in the trial a few patients experienced the potentially fatal reaction known as tumor lysis syndrome (TLS), a metabolic crisis when too many cancer cells die too quickly, causing their contents to spill into the bloodstream and threaten the health of several organs. This occurred in patients receiving higher doses; when tailored back, the patients returned to health and suffered no more TLS-related problems.

Source: ASH 2013