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Elisrasib monotherapy delivers an ORR of 78.0% and median PFS of 12.4 months in first-line KRAS G12C–mutant NSCLC (n=41) across all PD-L1 expression levels
Combination of elisrasib with pembrolizumab achieves an ORR of 81.3% in first-line KRAS G12C–mutant NSCLC (n=48) across all PD-L1 expression levels, with a 12-month PFS rate of 53.7%
SHANGHAI, June 1, 2026 /PRNewswire/ — D3 Bio Inc., a global clinical-stage biotechnology company dedicated to developing innovative oncology therapeutics, announced first-line (1L) clinical data of elisrasib monotherapy and elisrasib in combination with pembrolizumab from an ongoing Phase I/II study of elisrasib (D3S-001), its next-generation KRAS G12C inhibitor, in patients with KRAS G12C mutation–positive (G12Cmut) non–small cell lung cancer (NSCLC). The data were presented in a Clinical Science Symposium at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.
Findings from both cohorts, which demonstrate favorable safety and tolerability profiles along with highly promising antitumor activity in 1L G12Cmut NSCLC across all levels of PD-L1 expression, support continued evaluation of elisrasib in the first-line setting.
Elisrasib as First-Line Monotherapy for Patients with KRAS G12C Mutation–Positive NSCLC
Elisrasib monotherapy demonstrated highly promising preliminary antitumor activity. Forty-three patients with previously untreated G12Cmut NSCLC received elisrasib 600 mg once daily in 21-day cycles, with a median study follow-up of 8.5 months. In 41 efficacy-evaluable patients, the overall response rate (ORR) was 78.0% was observed across all levels of PD-L1 expression, with 76.2% ORR in patients with PD-L1 TPS <1% (N=21) and 80.0% in patients with PD-L1 TPS of ≥1% (N=20), respectively. The disease control rate (DCR) was 95.1%. The median progression-free survival (mPFS) was 12.4 months (95% CI: 6.8, NR), with a 12-month PFS rate of 50.8%. Median overall survival (OS) was not reached, with a 12-month OS rate of 90.0%. As of the data cutoff, 60.5% of patients remained on study treatment.
Elisrasib monotherapy was well tolerated, with Grade 3 or higher TRAEs observed in only 7% of patients and serious TRAEs in 2.3% of patients. No TRAEs led to elisrasib discontinuation, and no dose reductions were required.
Elisrasib plus Pembrolizumab as First-Line Combination Therapy for Patients with KRAS G12C Mutation–Positive NSCLC
Fifty-two patients with previously untreated G12Cmut NSCLC received elisrasib 600 mg once daily in combination with pembrolizumab 200 mg every 3 weeks (Q3W), with a median study follow-up of 5.7 months. Notably, the dose of elisrasib used in combination is elisrasib’s RP2D at 600mg QD which provides complete KRAS G12C target coverage.
The combination of elisrasib and pembrolizumab showed highly compelling antitumor activity in patients with previously untreated G12Cmut NSCLC. In 48 efficacy-evaluable patients, an ORR 81.3% was observed across all PD-L1 expression levels, with ORR of 70.6% in patients with PD-L1 TPS <1% (N=17), 72.7% in patients with PD-L1 TPS of 1% to 49% (N=11), and 95.0% in patients with PD-L1 TPS ≥50% (N=20), respectively. The overall DCR was 97.9%. The median PFS was not reached (95% CI: 8.4, NR), with a 6-month PFS rate of 74.6% and a 12-month PFS rate of 53.7%. Median OS was not reached, with a 12-month OS rate of 88.8%. As of the data cutoff, 82.7% of patients remained on study treatment.
The combination regimen demonstrated a safety profile consistent with the known profiles of each agent. Grade 3 or higher TRAEs occurred in 32.7% of patients, with most severe events attributable to pembrolizumab, and serious TRAEs reported in 17.3% of patients. No new or unexpected safety signals were identified for elisrasib, and the overall safety profile compared favorably with the established standard-of-care regimen of pembrolizumab plus chemotherapy.
Expert Commentary
Prof. Shun Lu, M.D., Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, and lead study presenter, said: “The first-line results for elisrasib are very encouraging, showing strong and consistent antitumor activity across PD-L1 expression subgroups, both monotherapy and in combination with pembrolizumab. Its favorable tolerability and rapid response onset further highlight its potential as a promising treatment option for patients with KRAS G12C-mutant NSCLC.”
“The compelling activity of elisrasib as monotherapy and in combination with pembrolizumab observed in the first-line NSCLC represents an exceptionally promising signal in this historically difficult-to-treat population,” said Dr. George Chen, Founder, Chairman, and Chief Executive Officer of D3 Bio. “We believe these results support the continued and accelerated evaluation of elisrasib in Phase 3 randomized studies.”
About Elisrasib (D3S-001)
Elisrasib is a next-generation KRAS G12C inhibitor designed for rapid, complete, and selective target engagement. It covalently binds the GDP-bound (OFF) form of KRAS G12C, effectively blocking nucleotide cycling and suppressing oncogenic signaling. Preclinical studies show robust potency, complete KRAS G12C engagement at clinically relevant exposures, and CNS penetration capability. Elisrasib is currently being evaluated globally in a Phase 2 monotherapy and combination trial across KRAS G12C–mutant solid tumors including NSCLC, CRC, and others.
Key Publications:
Cancer Discovery
Nature Medicine (2025) 31(8):2768–2777
About D3 Bio
D3 Bio is a global biotechnology company focused on the discovery, development, and registration of novel oncology and immunology therapies with first or best in class potential. Guided by deep clinical insight and biomarker-driven‑strategies, the Company is advancing a pipeline of programs targeting key oncogenic drivers and immune pathways. D3 Bio owns global rights to all its programs.
For further information, please visit www.d3bio.com
