Obinutuzumab Beneficial For Reducing Early Progression in FL?

January 22, 2019
Leah Lawrence

A study investigates whether FL patients had fewer early disease progression events when assigned to treatment with obinutuzumab plus chemotherapy.

Patients with follicular lymphoma in the GALLIUM trial had fewer early disease progression events when assigned to treatment with obinutuzumab plus chemotherapy compared with rituximab plus chemotherapy, according to a study published in Haematologica.

The study showed that this early disease progression was linked with poor prognosis and higher mortality risk, confirming the results of prior studies, according to researcher John F. Seymour, MBBS, PhD, of Royal Melbourne Hospital and University of Melbourne, and colleagues.

“Notably, there was little difference in the proportion of patients in each treatment arm with progressive disease after the 24-month time point, indicating that, to date, the protective effect of obinutuzumab-chemo against early progression has not been counterbalanced by any increased risk of later progression,” Seymour and colleagues wrote.

For the study, the researchers looked at data from 1,202 patients from the GALLIUM study, which randomly assigned patients with untreated follicular lymphoma to treated with obinutuzumab or rituximab-based immunochemotherapy. Previously published results from the trial showed that patients treated with obinutuzumab had significantly improved progression-free survival compared with rituximab-based treatment. With this analysis, the researchers evaluated early progression and its effects on overall survival.

Of the 1,202 patients randomized in GALLIUM, 1,071 were followed for response until at least 24 months. Progression of disease events occurred in 9.5% of patients assigned obinutuzumab and 16.3% of patients assigned rituximab. The average hazard ratio-based reduction in risk for a progression event by 24 months with obinutuzumab relative to rituximab was 46%.

The median post-progression follow-up was 22.6 months. At this timepoint, the risk for mortality was increased following a progression event, with higher risk associated with earlier disease progression.

There were 110 patients with progression by 24 months who were still alive at the 24-month landmark. Among these patients, the overall survival rate at 2 years after the landmark was 82.4% compared with 98.2% in patients who had not progressed by 24 months (hazard ratio [HR],12.2; [95% CI, 5.6–26.5]).

Commenting on the results of this study, Jonathan Friedberg, MD, director of Wilmot Cancer Institute at University of Rochester Medical Center, told Cancer Network, that these data confirm several prior observations of inferior outcome in patients who relapse early after chemoimmunotherapy. 

“Patients in GALLIUM who were treated with obinutuzumab were less likely to have early progression as compared with those treated with rituximab. Additional follow-up will be required to determine whether this finding translates to an overall survival benefit,” Friedberg said.

“For current practice, this manuscript emphasizes that patients with early progression of follicular lymphoma after chemoimmunotherapy require novel treatment approaches and should be referred for clinical trial consideration. It is premature at this time to conclude that all patients with follicular lymphoma should be treated with obinutuzumab-containing induction to decrease the risk of early progression, but additional follow-up of the GALLIUM study should provide clarity in this regard.”