Abstract 1032P
Background
Almost all nsqNSCLC pts harbored EGFR mutation ultimately develop resistance to targeted therapies, with ∼10-20% response rate and tolerance concern to platinum-based salvage treatment. Encouraging clinical data from IMpower150 has demonstrated atezo + beva + chemo are promising strategies. We initiated ML41256 to evaluate the efficacy and safety of atezo + beva, a chemo-free regimen for such pts.
Methods
ML41256 is an open-label, single-arm, phase II, multicenter study enrolled pts with PD-L1 ≥1%, EGFR+, Stage IIIB/IV nsqNSCLC after treatment failure of EGFR TKIs. All pts received atezo 1200mg and beva 15mg/kg q3w until progressive disease assessed per RECIST v1.1, unacceptable toxicity, or death. The primary efficacy endpoint would be investigator confirmed objective response rate (ORR). Simon’s minimax 2-stage design was used. The interim analysis would be performed for futility at the time of 19 pts completing ORR evaluation. Further testing would be halted if responders ≤ 6 in the first evaluable 19 stage 1 pts.
Results
By the cutoff date of 16th Jul. 2021, 20 pts were enrolled, and 1 pt without any post-baseline efficacy assessment was excluded from the ORR evaluable population. 8 were males; median age was 63.0 with 75% ECOG PS 1. Metastasis occurred in 100% pts (8 bone metastasis and 5 brain metastasis). Median follow-up was 5.3 m. Of 19 evaluable pts, ORR and disease control rate were 15.8% and 68.4% (3 partial response and 10 stable disease). Median progression-free survival and time to response were 2.8m and 1.4 m. Duration of response and overall survival were immature. Safety was analyzed in all 20 pts. 40% pts experienced grade ≥3 treatment-emergent adverse effect (TEAE). TEAE led to death and drug withdrawn in 1 and 4 pts. All immune-mediated toxicity were grade 1. No new safety signal was observed.
Conclusions
Enrollment was stopped due to not meet its preplanned rule for entering stage 2 in the interim analysis. However, atezo + beva was general tolerable and deep response in some pts. Further exploration is needed to identify pts most likely benefit from this chemo-free regimen.
Clinical trial identification
NCT04426825.
Editorial acknowledgement
Legal entity responsible for the study
Shanghai Roche Pharmaceuticals Ltd., Shanghai, China.
Funding
Shanghai Roche Pharmaceuticals Ltd., Shanghai, China.
Disclosure
All authors have declared no conflicts of interest.