Patients with follicular lymphoma (FL) who undergo disease progression within 24 months following front-line chemoimmunotherapy (POD24) had poor outcomes, according to observational studies and stand-alone trials. For a study, researchers sought to discover clinical characteristics that predicted POD24, therefore, they did a pooled analysis of 13 randomized clinical trials of patients with FL in the pre-and-post rituximab eras. Logistic regression models were used to examine the relationship between clinical variables and POD24. Cox regression was used to examine the relationship between POD24 as a time-dependent factor and subsequent overall survival (OS). A landmark investigation looked at the relationship between POD24 and OS in a sample of patients who were still alive 24 months following trial registration. 

Patients who did not advance after 24 months had a good performance status (PS), limited-stage (I/II) illness, a low-risk FL International Prognostic Index (FLIPI) score, normal baseline hemoglobin, and normal baseline β2 microglobulin (B2M) level. Male sex (odds ratio [OR], 1.30), PS >2 (OR, 1.63), B2M (>3 mg/L; OR, 1.43), and high-risk FLIPI score (3-5; OR, 3.14) were all associated with an elevated risk of advancement before 24 months in a multivariable logistic regression model. POD24 was linked with worse future OS in the time-dependent Cox model and the 24-month landmark analysis (hazard ratio, 4.85 and 3.06, respectively). 

The study was the largest pooled analysis of clinical trial data to date, validating POD24 as a reliable predictor of poor FL survival and identifying clinical predictors of early death and progression that could help in the development of comprehensive prognostic models that incorporated clinical and molecular predictors of POD24.