Investigational Drug Improves Efficacy of Aggressive Lymphoma Treatment

Polatuzumab vedotin plus bendamustine and rituximab increased complete response rates to 40% among patients with diffuse large B-cell lymphoma.

Genentech recently announced positive results from a phase 2 clinical trial that evaluated a combination therapy of investigational polatuzumab vedotin plus bendamustine and rituximab (Rituxan) (BR) compared with BR in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), according to a company press release.

Polatuzumab vedotin is a first-in-class anti-CD79b antibody drug conjugate, which binds to CD79b and targets B-cells, according to Genentech.

The researchers found that polatuzumab vedotin plus BR significantly increased complete response (CR) rates from 15% with BR alone to 40% with the combination therapy.

“As many as 40% of people with diffuse large B-cell lymphoma do not respond to initial therapy or experience the return of their disease, at which point their treatment options are limited and the prognosis is very poor,” said Sandra Horning, MD, chief medical officer and head of Global Product Development.

Included in the study were 80 patients with heavily pre-treated DLBCL who were ineligible for a hematopoietic stem cell transplant. Patients were randomized to receive polatuzumab vedotin plus BR or BR alone.

The investigators also found that the benefit of polatuzumab vedotin was observed across secondary endpoints, including best objective response and CR with the combination compared with BR alone, according to the release.

Patients treated with polatuzumab plus BR had a median overall survival of 11.8 months compared with 4.7 months for patients treated with BR alone.

Adding the investigational drug also more than tripled median progression-free survival to 6.7 months compared with only 2 months for those treated with BR alone, according to Genentech. The experimental combination also increased the time between treatment response and disease worsening.

Genentech reported that there were no additional safety concerns related to the addition of polatuzumab vedotin.

The FDA recently granted polatuzumab vedotin breakthrough therapy designation due to the positive results from this clinical trial, according to the release. Multiple ongoing studies are investigating the efficacy of the drug for non-Hodgkin lymphoma.

“The promising efficacy observed for polatuzumab vedotin in this study supports its potential as a new treatment option for people previously treated for this aggressive blood cancer, and we look forward to discussing the results with health authorities,” Dr Horning said.