Despite achievements in the therapy of relapsed and refractory classical Hodgkin lymphoma (r/r cHL) after anti-PD-1 therapy emergence, particular problems remain unresolved including the issue of anti-PD-1 therapy duration and criteria of therapy discontinuation. Our aim was to assess outcomes of patients with r/r cHL after nivolumab discontinuation (Nivo) depending on the response at the moment of therapy discontinuation and Nivo dose.
This retrospective analysis included 42 pts (9 male/33 female) with r/r cHL who discontinued Nivo due to different reasons: due to adverse events in 5 (12%) pts, Russian Nivo Named Patient Program or Nivo40 study (NCT03343665) discontinuation in 35 (88%) and other reasons in 2 (5%) pts. Median age - 35 (21-53). Median number of therapy lines - 5 (2-10). ASCT was conducted in 15 (36%) pts, brentuximab vedotin - in 19 (45%). At the moment of Nivo initiation disease progression was present in 30 (71%) pts, B-symptoms - in 24 (57%). Twenty-seven (64%) pts were treated with Nivo 3 mg/kg and 15 (36%) - Nivo 40 mg disregard of body mass. Nivo was discontinued in complete response (CR) in 36 (86%) pts and in partial response (PR) - in 6 (14%). Median number of Nivo cycles - 24 (11-30). Median number of Nivo cycles before the best overall response (BOR) achievement - 6 (6-24). Median time of Nivo duration after BOR achievement - 7 (0-16) months. Response to therapy was accessed by PET-CT using Lyric criteria.
Median follow-up after Nivo discontinuation was 26 (4-41) mo. All patients were alive at the moment of analysis. Median PFS for patients who discontinued Nivo in CR was 24 (95%CI: 11-37) mo, in PR - 8 (95%CI: 0-18) mo. Thus, the response at the moment of Nivo discontinuation significantly influenced 2-y PFS: 51% (95%CI: 32-66%) vs 0%, p=0.013. There were no significant differences in 2-y PFS between patients treated with different Nivo doses: 53% (95%CI: 31-71%) for 3 mg/kg vs 47% (95%CI: 15-74%) for 40 mg, p=0.55.
Durable remission is possible for patients with r/r cHL after Nivo discontinuation in CR. Moreover, Nivo dose did not influence the remission duration after Nivo discontinuation. There is need in prospective randomized trials assessing optimal Nivo treatment regimen and duration.
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All authors have declared no conflicts of interest.