A phase I/II study of first-in-human trial of JAB-21822 (KRAS G12C inhibitor) in advanced solid tumors.

Abstract

3089 Background: KRAS G12C mutation occurs in approximately 4% of non-small cell lung cancer (NSCLC), 1-2% of colorectal cancer (CRC) and other solid tumors in China. JAB-21822 (Jacobio, Beijing, PRC) is a highly selective, covalent oral inhibitor of KRAS G12C. Methods: NCT05009329 is an ongoing first-in-human, open label phase I/II study of JAB-21822 in patients with advanced solid tumors. The primary objective is to evaluate the safety and tolerability of JAB-21822. Other objectives include preliminary efficacy, pharmacokinetics, and biomarkers. Here we report the results from the dose escalation phase of the trial. Results: As of January 28th, 2022, 53 patients with a median age of 62 years (39-79) were enrolled in 5 different dose levels: 200mg QD, 400mg QD, 800mg QD, 400mg BID and 400mg TID. Most patients (55%) had ≥ 2 prior lines of therapy. No dosing-limiting toxicities were observed. Two treatment-related adverse events (TRAEs) were G4 neutropenia (1 in 400mg BID and 1 in 400mg TID). The most common TRAEs (≥ 10%) included anemia (24.5%), total bilirubin increase (20.8%), direct bilirubin increase (15.1%), proteinuria (13.2%) and indirect bilirubin increase (11.3%). Only Grade 1 and 2 TRAEs were observed in the QD cohorts. A total of 33 patients (22 NSCLC, 9 CRC and 2 pancreatic cancer) had at least 1 post-baseline tumor assessment; in the 800mg QD cohort, overall response rate (ORR) and disease control rate (DCR) were 50% (5/10) and 100% (10/10), respectively, including 4 non-confirmed partial response (PR); in the 400mg QD cohort had an ORR and DCR of 80% (4/5) and 100% (5/5) respectively, including 2 non-confirmed PR. Patients with NSCLC (400mg QD and 800mg QD), the ORR and DCR were 70% (7/10) and 100% (10/10), respectively, including 5 non-confirmed PR. With respect to the pharmacokinetics analysis, JAB-21822 was rapidly absorbed with an average Tmax of 2 hr and reached higher plasma exposures (Cmax and AUC0-24h) after a single dose and multiple doses at C1D8. Conclusions: JAB-21822 was well tolerated with impressive preliminary efficacy in patients with heavily treated solid tumors harboring KRAS G12C mutation. The study is enrolling patients in the expansion phase. Multiple JAB-21822-based combination trials are also ongoing. Clinical trial information: NCT05009329.