Early progression of disease in follicular lymphoma is a robust correlate but not a surrogate for overall survival

External Validation of the FLIPI Risk Score Measured at Diagnosis and POD24 Among Individuals With Follicular Lymphoma at the Time of Subsequent Relapse

BACKGROUND

The Follicular lymphoma international prognostic index (FLIPI) risk score and POD24 have previously been shown to have prognostic value in follicular lymphoma (FL), but the extent to which they can inform prognosis at the time of subsequent relapse is uncertain.

PATIENTS AND METHODS

We conducted a longitudinal cohort study of individuals diagnosed with FL between 2004 and 2010 in Alberta, Canada who received front-line therapy and subsequently relapsed. FLIPI covariates were measured prior to the initiation of front-line therapy. Median overall survival (OS), progression-free survival (PFS2), and time to next treatment (TTNT2) were estimated from the time of relapse.

RESULTS

A total of 216 individuals were included. The FLIPI risk score was highly prognostic at the time of relapse for OS (c-statistic = 0.70; HR[High vs. Low] = 7.38; 95% CI: 3.05-17.88), PFS2 (c-statistic = 0.68; HR[High vs. Low] = 5.84; 95% CI: 2.93-11.62) and TTNT2 (c-statistic = 0.68; HR[High vs. Low] = 5.72; 95% CI: 2.87-11.41). POD24 was not prognostic at the time of relapse for either OS, PFS2, or TTNT2 (c-statistic = 0.55).

CONCLUSION

The FLIPI score measured at diagnosis may help with the risk stratification of individuals with relapsed FL.

Time for an individualized approach to first-line management of follicular lymphoma

Follicular lymphoma is a heterogeneous B-cell lymphoma both in presentation and at progression. For most patients it is a chronic, relapsing indolent disease with overall survival expectations now potentially beyond 20 years. However, in a significant minority (~20%) who experience early progression or histological transformation after treatment, the disease no longer has an indolent behavior. This review looks at the development of prognostic indices, staging and therapies for follicular lymphoma, identifying where the data can, and cannot, guide the multidisciplinary team to determine an individualized approach to first-line therapy. A nuanced patient- and disease-specific approach is necessary to maximize disease response and survival while minimizing therapeutic toxicity.

Phase III Clinical Trials in First-Line Follicular Lymphoma: A Review of Their Design and Interpretation

Follicular lymphoma (FL) is one of the most common subtypes of non-Hodgkin lymphoma worldwide. Improved survival outcomes with rituximab-based therapy in clinical trials led to the establishment of rituximab-based immunochemotherapy as standard of care for first-line (1L) treatment of FL. In the GALLIUM trial, obinutuzumab-based immunochemotherapy demonstrated improved progression-free survival (PFS), prolonged time-to-next antilymphoma treatment (TTNT) and comparable overall survival (OS) compared with rituximab-based immunochemotherapy as 1L treatment for FL. Using GALLIUM as an example, this article aims to explain how improved outcomes in 1L treatment of FL have changed the landscape for the design and interpretation of future trials. As approved therapies for 1L FL already achieve good responses, it is becoming more difficult to design trials that demonstrate further treatment benefits with the currently accepted primary endpoints. New endpoints are needed to reflect the long remission times, low relapse rates, and impact of subsequent therapies in FL. PFS is used as a primary efficacy endpoint in registrational clinical trials for indolent malignancies like FL, where improvement in OS is not always observed due to the large number of patients and long study duration required to demonstrate a clear survival benefit. However, there are limitations to using PFS as the primary endpoint. Other potential endpoints, including TTNT, progression of disease within 2 years, response rate, and minimal residual disease status are explored.

Phase III Clinical Trials in First-Line Follicular Lymphoma: A Review of Their Design and Interpretation

Follicular lymphoma (FL) is one of the most common subtypes of non-Hodgkin lymphoma worldwide. Improved survival outcomes with rituximab-based therapy in clinical trials led to the establishment of rituximab-based immunochemotherapy as standard of care for first-line (1L) treatment of FL. In the GALLIUM trial, obinutuzumab-based immunochemotherapy demonstrated improved progression-free survival (PFS), prolonged time-to-next antilymphoma treatment (TTNT) and comparable overall survival (OS) compared with rituximab-based immunochemotherapy as 1L treatment for FL. Using GALLIUM as an example, this article aims to explain how improved outcomes in 1L treatment of FL have changed the landscape for the design and interpretation of future trials. As approved therapies for 1L FL already achieve good responses, it is becoming more difficult to design trials that demonstrate further treatment benefits with the currently accepted primary endpoints. New endpoints are needed to reflect the long remission times, low relapse rates, and impact of subsequent therapies in FL. PFS is used as a primary efficacy endpoint in registrational clinical trials for indolent malignancies like FL, where improvement in OS is not always observed due to the large number of patients and long study duration required to demonstrate a clear survival benefit. However, there are limitations to using PFS as the primary endpoint. Other potential endpoints, including TTNT, progression of disease within 2 years, response rate, and minimal residual disease status are explored.