Sequential treatment for patients with chronic lymphocytic leukemia who have received bendamustine

This study aimed to investigate the effectiveness of obinutuzumab and venetoclax after bendamustine treatment in patients with chronic lymphocytic leukemia (CLL). This study concluded that this sequence of treatment caused no unexpected side effects. It also concluded that the outcomes were comparable to established therapies for CLL.

Bendamustine (Levact) is a chemotherapy used to treat CLL. Obinutuzumab (Gazyva) and venetoclax (Venclexta) are targeted treatments that have shown good activity in CLL when administered alone. They target and kill cancer cells. It was not known if the combination of these drugs would be effective when administered after bendamustine treatment in patients with CLL.

This study involved 63 patients with CLL. 54% of these patients had no previous treatment. 46% of patients had relapsed or refractory disease (cancer grows back or does not respond to treatment). Patients received sequential treatment of debulking (treatment to reduce the volume of tumor). This involved 2 cycles of bendamustine. This was and followed by induction (treatment to achieve remission) with obinutuzumab and venetoclax. The main outcome to record was the number of patients achieving an overall response (tumor size reduction) at the end of treatment.

At the end of treatment, 95% of patients had responded. 100% of the group who had no previous treatment responded. 90% of the relapsed/refractory disease patients responded.

Common side effects during debulking were neutropenia (low level of white blood cells; 11%) and anemia (low level of red blood cells; 11%). Thrombocytopenia (low blood platelet count) and infection were also common (6% each).

Common side effects during induction were neutropenia (44%), infection (14%) and thrombocytopenia (12%). Infusion-related reactions (reaction from treatment administration) and a new cancer occurring were also reported. Serious, life-threatening side effects were infections and cytopenia (reduced levels of mature blood cells).

This study concluded that this sequence of treatment caused no unexpected side effects. It also concluded that outcomes were comparable to established therapies for chronic lymphocytic leukemia.

This was a phase 2 trial, with a rather small number of patients. Further larger trials are needed to confirm results.