The KRAS G12D-targeted protein degrader setidegrasib demonstrated encouraging antitumor activity and a manageable safety profile in patients with KRAS G12D-mutant non-small cell lung cancer (NSCLC), according to phase 1 data presented at the 2026 European Lung Cancer Congress (ELCC) and published in The New England Journal of Medicine.

Clinical Takeaway

Setidegrasib at the 600 mg recommended phase 2 dose showed promising efficacy signals in heavily pretreated NSCLC patients, with an overall response rate of 35.8% and particularly encouraging activity in second-/third-line patients (37.5% ORR) and light/nonsmokers (47.1% ORR). The safety profile was characterized by manageable infusion-related reactions, most commonly occurring during the first infusion, with relatively low rates of serious treatment-related toxicity.

Drug Profile & Mechanism

Setidegrasib represents a novel therapeutic approach as a KRAS G12D-targeted protein degrader. Unlike traditional treatments that block cancer-causing proteins, setidegrasib facilitates the breakdown and removal of the KRAS G12D protein from cancer cells, potentially leading to more potent and durable therapeutic effects.

Target Population

Adults with locally advanced unresectable or metastatic solid tumors harboring KRAS G12D variants. The NSCLC cohort analysis included heavily pretreated patients with a median of 2 prior lines of therapy, with 93.3% previously receiving both platinum-based chemotherapy and immune checkpoint inhibition.

Study Design

  • Design: Phase 1, open-label study
  • Population: 203 patients total (59 NSCLC, 124 pancreatic ductal adenocarcinoma, 20 other solid tumors)
  • NSCLC cohort characteristics:
    • Median age: 68 years
    • 62.2% female
    • 77.8% had ECOG performance status 1
  • Dose: 600 mg (recommended phase 2 dose)

Endpoints

  • Primary: Safety
  • Secondary: Overall response rate (ORR), disease control rate, duration of response (DOR)
  • Exploratory: Progression-free survival (PFS), biomarker analyses

Efficacy Outcomes

  • Overall Response Rate:
    • All patients: 35.8% (16/45 evaluable patients)
    • Second-/third-line: 37.5%
    • Light/nonsmokers: 47.1%
  • Duration of Response:
    • Median DOR: not reached in all patients and second-/third-line subgroups
    • Light/nonsmokers: 9.7 months
    • 6-month DOR estimate in second-/third-line: 76%
  • Progression-Free Survival: Median PFS of 11.2 months in second-/third-line patients

Safety

  • Treatment-related adverse events (TRAEs): 97.8% (44/45 patients)
  • Grade ≥3 TRAEs: 13.3% (6 patients)
  • Serious TRAEs: 6.7% (3 patients)
  • Discontinuations or fatalities: None due to TRAEs
  • Most common TRAE: Infusion-related reactions in 80% of patients, most commonly during the first infusion (78%), generally low grade and manageable

Biomarker Analyses

Pharmacodynamic analyses demonstrated on-target activity with setidegrasib:

  • Tumor KRAS G12D protein reduction: Median 70.6% decrease
  • Circulating tumor DNA (ctDNA) changes: Observed as early as first treatment cycle
  • ctDNA correlation with PFS:
    • ≥50% ctDNA decline: median PFS 9.6 months
    • <50% ctDNA decline: median PFS 2.6 months

Key Clinical Implications

✔ Setidegrasib demonstrates meaningful antitumor activity in heavily pretreated KRAS G12D-mutant NSCLC with a manageable safety profile dominated by infusion reactions

✔ Durable responses and encouraging PFS data support potential for meaningful clinical benefit in later-line treatment settings

✔ Strong pharmacodynamic evidence of on-target KRAS G12D protein degradation validates the mechanism of action

✔ ctDNA monitoring may serve as an early biomarker for treatment response and patient selection

✔ Combination strategies with immune checkpoint inhibitors leverage potential reversal of KRAS-driven immune evasion

Future Development

Development is advancing toward a phase 3 monotherapy trial in previously treated advanced NSCLC. Additionally, first-line combination studies with immune checkpoint inhibitors are underway, based on the rationale that KRAS inhibition may reverse immune evasion mechanisms and enhance T-cell infiltration.

As study presenter Dr. Philippe Cassier noted, “KRAS contributes to the immune desert or the immune escape. The fact that we’re relieving the immune suppression probably helps the T-cell infiltration. Regarding the positioning of the combination, I think that it will have to be positioned in the first line.”

Bottom Line

Setidegrasib represents a promising new therapeutic approach for KRAS G12D-mutant NSCLC, demonstrating encouraging efficacy signals and a manageable safety profile in heavily pretreated patients. Strong pharmacodynamic evidence of target engagement, combined with durable responses, supports continued development in both monotherapy and combination settings.

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