Savolitinib plus osimertinib in epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer with MET overexpression and/or amplification following disease progression on osimertinib: primary results from the phase II SAVANNAH study.

BACKGROUND

MET-based resistance following osimertinib treatment for epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC) is common. We report the primary analysis of the phase II SAVANNAH study (NCT03778229) evaluating savolitinib plus osimertinib in this setting.

PATIENTS AND METHODS

Patients had EGFR-mutated, advanced NSCLC with MET overexpression and/or amplification. MET cut-offs were initially MET immunohistochemistry (IHC)3+/≥50% (3+ intensity in ≥50% of tumor cells) and/or FISH5+ (≥5 MET gene copies or MET/chromosome 7 centromere ratio ≥2), and increased to MET IHC3+/≥90% and/or FISH10+ after a preliminary analysis. Patients received oral savolitinib [300 mg twice daily (b.i.d.) or once daily (o.d.), or 600 mg o.d.] plus osimertinib 80 mg o.d., or savolitinib 300 mg b.i.d. plus placebo. A primary endpoint was investigator-assessed objective response rate (ORR) in patients with progression on first-line osimertinib and MET IHC3+/≥90% and/or FISH10+ status receiving savolitinib 300 mg b.i.d. plus osimertinib (primary efficacy population). Safety was analyzed in all patients receiving savolitinib plus osimertinib.

RESULTS

Of the 365 patients treated, 341 received savolitinib plus osimertinib, with 80 of these included in the primary efficacy population. Investigator-assessed confirmed ORR in the primary efficacy population was 56.3% [95% confidence interval (CI) 44.7% to 67.3%]; the median duration of response (mDoR) was 7.1 months (95% CI 5.6-9.6 months); the median progression-free survival (PFS) was 7.4 months (95% CI 5.5-7.6 months). Blinded independent central review was consistent: confirmed ORR 55.0% (95% CI 43.5% to 66.2%); mDoR 9.9 months (95% CI 6.0-13.7 months); median PFS 7.5 months (95% CI 6.4-11.3 months). The most common any grade adverse events in patients receiving savolitinib plus osimertinib were peripheral edema (46.0%), nausea (40.5%), and diarrhea (23.2%).

CONCLUSIONS

Savolitinib 300 mg b.i.d. plus osimertinib demonstrated high, clinically meaningful and durable responses in patients with EGFR-mutated, advanced NSCLC with MET IHC3+/≥90% and/or FISH10+ status following progression on first-line osimertinib. The combination was well tolerated and may provide a new oral targeted treatment approach in this setting.