The combination of osimertinib and savolitinib showed clinically meaningful improvement in objective response rate compared to osimertinib alone, according to research presented today at the International Association for the Study of Lung Cancer 2024 World Conference on Lung Cancer.

Approximately 20% to 30% of EGFRm NSCLC patients exhibit primary unsatisfactory therapeutic effect to EGFR-TKIs therapy, according to Jin-Ji Yang, Guangdong Lung Cancer Institute, Guangdong Provincial People's Hospital in Southern Medical University, China.

Professor Yang and his colleagues theorised that osimertinib in combination with savolitinib, a selective MET inhibitor as first-line treatment, may improve efficacy and overcome MET-driven primary resistance in these patients.

The FLOWERS trial was established as a prospective, two-arm, randomised, multicenter study which enroled 44 patients--23 were randomised to receive 80 mg qd of oral osimertinib alone (cohort 1) and 21 patients received 80 mg qd of osimertinib with 300 mg bid of savolitinib (cohort 2).

Median follow up was 8.2 months, and the primary endpoint was objective response rate.

The secondary endpoints included disease control rate, duration of response, progression-free survival, overall survival (OS), safety and tolerability.

MET overexpression  is defined by IHC 3+ in ≥ 75% of tumour cells. The criteria of MET amp are MET gene copy number (GCN) ≥5 and/or MET/CEP7 ratio ≥2 by tissue FISH or MET GCN≥5 by tissue NGS.

Professor Yang reported that the objective response rate in cohort 1 and cohort 2 were 60.9% (95%CI, 38.5-80.3%) and 90.5% (95% CI, 69.6-98.8%), respectively, with disease control rate of 87% (95% CI, 66.4-97.2%) and 95.2% (95% CI,76.2-99.9%), respectively. The median duration of response was 8.4 months and 18.6 months, respectively, and is not yet mature.

“Osimertinib with savolitinib demonstrated a manageable safety profile, and with these results, has the potential to provide a novel first-line treatment option for patients who do not respond well to EGFR-TKIs therapy,” Professor Yang reported.

Source: International Association for the Study of Lung Cancer