Abstract 144P
Background
Neoadjuvant chemoimmunotherapy have a promising efficacy in resectable non-small cell lung cancer (NSCLC). We aimed to investigate the efficacy and safety of neoadjuvant immunotherapy plus chemotherapy for stage IIB-IIIB NSCLC.
Methods
Pts with stage IIB-IIIB, wildtype EGFR/ALK NSCLC, ECOG PS 0-1 were eligible. All pts received 2-4 cycles of toripalimab (240mg, q3w) plus double platinum-based chemotherapy. All pts were assessed by imaging/surgical indication after 2 cycles of treatment. Pts who cannot undergo surgery will be reassessed after another 1-2 cycles of neoadjuvant therapy. Primary endpoints were major pathological response (MPR), complete pathological response (pCR). Secondary endpoints were objective response rate (ORR), R0 resection rate and safety.
Results
A total of 81 pts (median age: 62, IQR: 45-76; female: 7, 8.6%, squamous cell carcinoma: 63, 77.8%) were enrolled since Dec 2020. Disease distribution in stage IIB, IIIA and IIIB consisted of 27, 41 and 13 pts, respectively. 16 pts were in the preoperative stage or unsuitable for surgery. 65 pts underwent R0 resection. 42 pts (42/65, 64.6%) achieved MPR, including 31 pts (31/65, 47.7%) with pCR. 62 pts received 2 or 3 cycles of treatment, and no significant difference in MPR or pCR rate was observed between 2 and 3 cycles of treatment (32/48, 66.7% vs 8/14, 57.1%, p=0.512; 25/48, 52.1% vs 5/14, 35.7%, p=0.281). After 2 cycles of treatment, the primary tumor shranked significantly with a -40% (IQR: -100%, +25%) median regression rate, and tended to flatten with a -4.63% (IQR: -21.54%, +21.15%) median regression rate after another 1-2 cycles. Among 31 pts who underwent imaging evaluation again after 2-cycle treatment assessment, 19 pts (19/31, 61.3%) still had tumor regression. 10 pts of these (10/19, 52.6%) received 3-4 cycles of treatment, and 9 pts (9/19, 47.4%) did not receive further treatment and continued regression was also observed. 69 pts (69/81, 85.2%) experienced TRAEs.
Conclusions
Neoadjuvant toripalimab and chemotherapy is a promising treatment for pts with stage IIB-IIIB NSCLC. Continued tumor regression after chemoimmunotherapy is not uncommon, and it is not entirely dependent on further cycles of neoadjuvant therapy.
Clinical trial identification
NCT04606303.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.