LUGANO, Switzerland – Adding the immunomodulator lenalidomide (Revlimid) to standard chemotherapy for patients with newly diagnosed ABC-type diffuse large B-cell lymphoma (DLBCL) – the so-called R2-CHOP regimen – did not significantly improve either progression-free or overall survival, compared with R-CHOP alone, investigators in the phase 3 ROBUST trial found.
Dr. Umberto Vitolo
Among 570 patients with activated B-cell (ABC) type DLBCL followed for a median of 27.1 months, median progression-free survival (PFS) – the primary endpoint – had not been reached either for patients randomized to R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin and prednisone) plus lenalidomide (R2-CHOP) or R-CHOP plus placebo.
The 1-year and 2-year PFS rate with R2-CHOP was 77%, compared with 75% for R-CHOP, and 2-year PFS rates were 67% and 64%, respectively, and neither comparison was statistically significant reported Umberto Vitolo, MD, from the Citta della Salute e della Scienzia Hospital and University in Turin, Italy.“The future direction is that promising preclinical data with next-generation immunomodulatory agents will be evaluated in future DLBCL clinical trials,” he said at the International Conference on Malignant Lymphoma.
The ROBUST trial is the latest in a long line of studies that failed to show improvement in outcomes with the addition of a novel agent to R-CHOP.
The rationale for adding lenalidomide to R-CHOP came from in-vitro studies showing antiproliferative and immunomodulatory action of lenalidomide against DLBCL, as well as two proof-of-concept clinical studies (REAL07 and MC078E) indicating efficacy against non–germinal center–like B (GCB) type DLBCL, Dr. Vitolo said.
In the ROBUST trial, investigators across 257 global sites enrolled 570 patients with ABC-type DLBCL, stratified them by International Prognostic Index (IPI) score (2 vs. 3 or greater), bulky disease (less than 7 cm vs. 7 cm or more), and age (younger than 65 years vs. 65 years and older) and randomly assigned them to receive R-CHOP with either oral lenalidomide 15 mg or placebo daily on days 1-14 of each 21-day cycle for six cycles.
All patients were required to have neutropenia prophylaxis according to local practice, with either a granulocyte- or granulocyte-macrophage colony-stimulating factor.
The efficacy analysis was by intention-to-treat and included 285 patients in each arm.
The investigators found no significant difference in the primary endpoint of PFS. Overall response rates (ORR) and complete response (CR) rates were high in both arms. The ORR was 91% in each arm, and the CR rate was 69% for R2-CHOP and 65% for R-CHOP.
Event-free survival (EFS) – a composite of first disease progression, death, or relapse after CR or start of second-line therapy – also did not differ significantly between the groups. The 1-year and 2-year EFS rates were 68% vs. 71% and 59% vs. 61%, respectively. The median EFS was not reached in either arm.
Similarly, overall survival did not differ between the groups. At 48 months of follow-up, 57 patients in the R2-CHOP arm and 62 patients in the R-CHOP arm had died. Respective 1- and 2-year overall survival rates were 91% vs. 90%, and 79% vs. 80%.
In the safety analysis, which included 283 patients in the R2-CHOP arm and 284 in the placebo/R-CHOP arm, there were no new safety signals observed. In all, 78% of patients in the lenalidomide arm and 71% in the placebo arm had at least one grade 3 or greater adverse events. The most common adverse events were hematologic, including neutropenia, febrile neutropenia, anemia, thrombocytopenia, and leukopenia.
The ROBUST study was funded by Celgene. Dr. Vitolo reported consulting and speaker’s bureau fees and research funding from the company.
SOURCE: Vitolo U et al. 15-ICML, Abstract 005.