OA02.02 Phase 1 Study of Safety, Tolerability, PK and Efficacy of AMG 510, a Novel KRASG12C Inhibitor, Evaluated in NSCLC

The KRASG12C mutation is found in approximately 14% of lung adenocarcinoma and 11% of NSCLC pts. Currently, no approved therapy targets this mutation. AMG 510 is a novel small molecule that specifically and irreversibly inhibits KRASG12C by locking it in an inactive GDP-bound state. A phase 1, first-in-human, open-label, multicenter study (NCT03600883) is evaluating the safety, tolerability, PK, and efficacy of AMG 510 in adult pts with locally-advanced or metastatic KRASG12C mutant solid tumors, including NSCLC pts. Safety is the primary endpoint; ORR (assessed every 6 wks), DOR, PFS, and PK are key secondary endpoints. Important inclusion criteria: KRASG12C mutation identified through DNA sequencing; measurable or evaluable disease; progression on standard therapy; ECOG PS ≤2; life expectancy >3 mo. Important exclusion criteria: active brain metastases; myocardial infarction within 6 mo. The maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) will be identified during the dose exploration. Once identified, additional pts with advanced solid tumors carrying the KRASG12C mutation will be enrolled during dose expansion. AMG 510 is given PO until disease progression, intolerance, or consent withdrawal. As of 4 April 2019, thirteen [5 men and 8 women; median age 63 yrs (range: 53–77)] of 35 pts enrolled in 4 dose exploration cohorts have NSCLC. These pts had a median of 3 (range: 1–5) prior lines of treatment (tx). On-study tx duration had a median of 59 days (range:9–192 d). No DLTs have been reported. Six NSCLC pts reported 10 treatment-related AEs (6 grade 1; 2 grade 2; 2 grade 3). The grade 3 related AEs were anemia in a pt with baseline grade 2 anemia and diarrhea lasting 2 d in a second pt. The most frequently reported AEs were decreased appetite (n=4 subjects) and diarrhea (n=3 subjects). Best tumor response has been evaluated in 10 NSCLC pts; 3 pts have not reached their first assessment. Of these 10 evaluable pts, 5 pts had a PR (2 of which are confirmed PRs), 4 had SD and 1 had PD. Of 13 NSCLC pts, 11 pts remain on-study and continue their AMG 510 and 2 pts have discontinued treatment due to PD during study wks 6 and 26. AMG 510 has been well tolerated at all 4 dose levels explored and has shown antitumor activity when administered as monotherapy to pts with advanced KRASG12C mutant NSCLC. Enrollment is on-going.