Verastem Inc. said a combination of duvelisib and certain other cancer drugs was effective in reducing the disease in certain blood cancer patients.
Verastem was evaluating duvelisib along with a drug combination commonly referred to as FCR, which includes fludarabine and cyclophosphamide as well as Roche Holding AG's Rituxan, in a phase 1b/2 study as an initial treatment in younger patients with chronic lymphocytic leukemia, or CLL.
CLL is a type of cancer in which the bone marrow produces too many lymphocytes, a type of white blood cell.
About 94% of the patients in the study saw a reduction in their cancer in response to the duvelisib combination regimen, a metric called overall response rate. About 26% of patients had no detectable cancer after treatment — known as a complete response — or experienced a complete response with incomplete blood count recovery. Meanwhile, 68% of patients saw their disease decline but not completely go away.
Patients in the study experienced a 76% bone marrow minimal residual disease negativity, a measure of how long a patient lives without the disease returning after treatment. This rate is "significantly higher than historical data with FCR," said Diep Le, chief medical officer of Verastem.
The most common treatment-related side effects were low blood platelet count, low levels of white blood cells called neutrophils and a lack of healthy red blood cells or hemoglobin. Serious side effects included an excess of enzymes in the liver, fever in patients with low neutrophil levels, pneumonia and inflammation in the colon's inner lining.
The Needham, Mass.-based biotechnology company had previously presented positive results in an extension of a phase 3 study of duvelisib at the recently held 2018 American Society of Clinical Oncology meeting.