An open-label, randomized phase III study of early switch maintenance vs delayed second-line nivolumab in advanced stage squamous non-small cell lung cancer (NSCLC) patients after standard first-line platinum-based chemotherapy-EDEN trial GOIRC 04-2016.

Background: As for squamous (Sq)-NSCLC, Checkmate-017 trial showed a significant overall survival (OS) improvement in favor of Nivolumab (Nivo) over Docetaxel in 2nd-line. We hypothesized that anticipating Nivo use, as early switch maintenance after 1st-line chemotherapy (CHT), might have improved survival as compared to delayed 2nd-line treatment.

Methods: EDEN was an open-label, 2-arm, phase III study which randomized (1:1) stage IIIB/IV Sq-NSCLC pts non-progressive after 1st-line platinum-based CHT, to receive early Nivo as switch maintenance (Arm A) or standard best supportive care followed by 2nd-line Nivo at disease progression (Arm B). In both arms, Nivo was administered at the dose of 240 mg i.v. every 2 weeks until progressive disease, intolerable toxicity, or for a maximum of 2 years. The primary endpoint was OS.

Results: From Sep 2017 to Aug 2020 125 patients (62 Arm A vs 63 Arm B) were randomized from 32 Italian centers. Accrual was stopped early, before the planned sample size (388 pts) was reached, because of registration of ICPIs in 1st-line. Most patients were male (79.2 %), current/former smokers (93.6 %), had stage IV (74.4 %), performance status 0-1 (98.4 %). mOS (95 % CI) was 14.9 (10.4-18.6) months in arm A vs 18.8 (14.4-21.1) months in arm B (HR 1.09, 95 %CI 0.74-1.62, p = 0.659).

Conclusions: In advanced Sq-NSCLC, the use of Nivo as switch maintenance after 1st-line CHT, does not improve OS compared to its use as 2nd-line. Although the optimal use of ICPIs remains in 1st-line, its role as maintenance has to be better investigated.

Clinicaltrials: gov: registration number: NCT03542461.