Results from a 13-year follow-up of a trial comparing two types of rituximab-based chemotherapy as upfront treatment for patients with follicular lymphoma show an “extraordinary improvement” in overall survival, compared with the prerituximab era.
In a finding that the researchers termed “somewhat unexpected,” complete remission was the strongest factor in long-term survival.
Between March 2000 and May 2005, researchers enrolled 136 high-risk follicular lymphoma patients in theto evaluate the superiority of high-dose chemotherapy with rituximab and autograft (R-HDS) versus conventional chemotherapy with rituximab (R-CHOP) as frontline therapy. At a median follow-up of 4 years, there was no survival advantage for R-HDS.
In the current analysis – that had a 13-year median follow-up – median survival had not yet been reached. As of February 2017, two-thirds of all patients were alive at their last follow-up. Overall survival was 68.5% in the R-CHOP arm and 64.5% in the R-HDS arm, Riccardo Bruna, MD, of the European Institute of Oncology in Milano, Italy, and his colleagues, reported in.
The main causes of death for the 46 patients who had died as of long-term follow-up were disease progression and secondary malignancies. Other causes included cardiovascular events, infections, graft failure following autograft, anaphylactic shock, and late sudden death.
Complete remission was seen in 98 patients (73.1%) overall – 59.1% in the R-CHOP arm and 86.7% in the R-HDS arm. Achieving durable complete remission was associated with prolonged survival, the researchers reported. Of the 79 patients in complete remission at 2 years after the start of treatment, 65 (82.3%) were alive at 13 years, compared with 21 (58.3%) of 36 patients who had an early relapse (P = .003).
“[Complete remission] achievement was the most important factor for prolonged survival,” the researchers wrote. “The importance of disease response is further emphasized by the first-time observation that [molecular remission] achievement is associated with survival duration and a high proportion of patients had prolonged survival in the absence of disease recurrence.”
The researchers reported that this is longest ever follow-up reported for first-line treatment of follicular lymphoma with rituximab-based chemotherapy.
This work was supported in part by the Ministero Italiano Università e Ricerca and by Banca del Piemonte. The initial clinical trial was supported by Compagnia di San Paolo, Regione Piemonte, and Roche, which provided rituximab for the study.
SOURCE: Bruna R et al. Haematologica. 2019 Apr 11. .