‘Real-World’ Follicular Lymphoma Study Examines the Negative Effect of Early Progression

The majority of patients diagnosed with follicular lymphoma received a rituximab-based regimen across all lines of treatment, according to a recent real-world study. However, a smaller percentage of patients whose disease progressed early received rituximab regimens compared with non-early progressors.

Additionally, patients with early progression had significantly worse overall survival compared with non-early progressors, highlighting “the negative impact of early progression on overall survival in the rituximab era,” according to researcher Vicki A. Morrison, MD, of the University of Minnesota, Hennepin County Medical Center in Minneapolis, and colleagues.

“Further research is warranted to better understand factors correlated with early progression, including those leading to front-line treatment selection in patients with follicular lymphoma,” they wrote in Clinical Lymphoma, Myeloma & Leukemia.

The study, which examined treatment patterns and survival outcomes, included data from 1,346 patients taken from the Humedica electronic medical record database from 2008 to 2015. In addition to treatment regimens, the researchers compared survival outcomes between patients who had evidence of disease progression at 2 years after first-line therapy, and those who did not.

The median age of included patients was 67 years. For first-line therapy, combination treatments were more commonly used than single-agent therapy (61.4% vs 38.6%), and more than 90% were rituximab based. The most common rituximab-based therapies were bendamustine/rituximab (43.8%); rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 25.5%); and rituximab plus cyclophosphamide, vincristine, and prednisone (R-CVP; 12.8%).

Overall, the use of combination regimens was less common among early progressors than non-early progressors (86.2% vs 96.8%). Specifically, bendamustine/rituximab was more common among non-early progressors (50.4% vs 22.6%), but R-CHOP and R-CVP were more common among early progressors.

In the second line, combination therapy was again more commonly used (65.7% vs 34.3%), with bendamustine/rituximab and R-CHOP remaining the most common combinations.

Only 45 patients received third-line treatment. Again, combination therapy was more commonly used than single-agent therapy (64.4% vs 35.6%).

“With changes in the treatment landscape for follicular lymphoma, it is important to evaluate survival outcomes in the real-world setting using current data,” the researchers wrote.

After completion of first-line therapy, the overall survival rate at 2 years was 86.9%, with median overall survival not reached. The 2-year progression-free survival rate was 64.6%, with a median of 48.1 months.

Non-early progressors had significantly better overall survival at 2 years compared with early progressors (90.4% vs 76.8%; P < .001). No median overall survival was reached for either group. At the end of study follow-up, the overall survival rate was 59.9% for early progressors compared with 69.8% for non-early progressors (P < .001).

The researchers acknowledged several limitations to the study, including its retrospective nature and a lack of detailed information, such as Follicular Lymphoma International Prognostic Index risk factors, genetic mutation information, World Health Organization pathologic grade, and tumor stage.

Commenting on the results, Jonathan W. Friedberg, MD, MMSc, director of the Wilmot Cancer Institute at the University of Rochester, told Cancer Network that, historically, treatment patterns for follicular lymphoma have been highly variable across the United States and internationally.

“There have been very few discoveries beyond rituximab that have changed overall survival in follicular lymphoma and a lot of treatment choices are made based upon preferences that physicians or patients have regarding the importance of endpoints like progression-free survival vs side effects of treatment,” Friedberg said.

In this study, the researchers showed that, not surprisingly, people are using rituximab-based treatment. It also confirmed previously published data that showed that if a patient progresses early after initial treatment, then that negatively impacts overall survival, Friedberg said.

“The ability to use these types of experiences to make changes to practice is limited because they are not randomized experiences,” he said.