332P - A phase II, open-label, single-center study of QL1706 plus platinum doublet chemotherapy with bevacizumab as first-line treatment in patients with advanced NSCLC: Data from EGFR mutant cohort

Background

QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, showed promising antitumor efficacy in advanced solid tumors including NSCLC in a phase (Ph) I trial. Here, we report the efficacy and safety results from the EGFR mutant cohort of an ongoing Ph II study of QL1706+chemotherapy (chemo)+bevacizumab in patients (pts) with advanced NSCLC.

Methods

Eligible pts had a pathologically confirmed diagnosis of stage IV non-squamous NSCLC with EGFR-sensitizing mutation; had measurable disease; and had experienced disease progression or could not tolerate EGFR TKIs+bevacizumab/anlotinib. Pts with NSCLC harboring T790M mutation should have progressed on or could not tolerate the third generation EGFR TKIs. Stable/treated brain metastases were permitted. Pts received QL1706 (5.0 mg/kg), bevacizumab, pemetrexed, and carboplatin on day 1 of each 21-day cycle for 4 cycles in the induction treatment. In the maintenance phase, pts received QL1706, bevacizumab, and pemetrexed treatment for up to 24 months. Response was assessed by the investigator per RECIST v1.1.

Results

31 pts with EGFR mutant NSCLC were enrolled. The median age was 55 years (range: 39 to 74). 19 (61.3%) pts previously received the third generation EGFR TKIs. 16 (51.6%) pts previously received antiangiogenic therapy. As of 31 May 2022, the ORR was 64.5% (20/31) and DCR was 93.5% (29/31). PFS was not yet mature. The 6-month PFS rate was 61.3%. The median follow-up for OS was 5.75 months (IQR: 4.86, 7.10). TRAEs were observed in 30 (96.8%) pts. 10 (32.3%) pts experienced grade (Gr) ≥3 TRAEs. The most common TRAEs (>40%) were anemia (77.4%); decreased appetite (61.3%); AST increased (45.2%); and constipation (41.9%). The most common Gr ≥3 TRAEs were platelet count decreased (9.7%) and anemia (9.7%). 8 (25.8%) pts experienced treatment-related SAEs. As of data cutoff, 23 pts were still on treatment.

Conclusions

QL1706+platinum-based chemo+bevacizumab demonstrated promising clinical activity, with favorable tolerability in pts with EGFR mutant NSCLC and failed in EGFR TKI therapy. Further investigations in this setting are continuing.

Clinical trial identification

NCT05329025.

Editorial acknowledgement

Legal entity responsible for the study

Qilu Pharmaceutical Co., Ltd.

Funding

Qilu Pharmaceutical Co., Ltd.

Disclosure

T. Wu, L. Lu, S. Xue: Other, Personal, Full or part-time Employment: Qilu Pharmaceutical. All other authors have declared no conflicts of interest.