OA02.02 Safety and Preliminary Clinical Activity of Ropotrectinib (TPX-0005), a ROS1/TRK/ALK Inhibitor, in Advanced ROS1 Fusion-Positive NSCLC

Ropotrectinib is a potent ROS1/TRK/ALK inhibitor with a >90-fold greater ROS1 potency than crizotinib. Preclinical studies demonstrate robust activity against all known ROS1 resistance mutations, including solvent-front mutation G2032R. In this Phase 1 study (NCT03093116), TKI-naïve and TKI-refractory (≥1 TKI) pts with advanced ALK/ROS1/TRK+ solid tumors received ropotrectinib. Asymptomatic brain metastases were allowed. Primary objectives were to determine MTD and RP2D, with safety, pharmacokinetics, and preliminary antitumor efficacy as the secondary objectives. This is a safety analysis of all pts and subgroup efficacy analysis of the ROS1+ NSCLC pts on the study. As of 16-April-2018, 72 pts have been treated at 6 dose levels from 40mg QD to 200mg BID. Most AEs were grade 1-2. Common (>10%) treatment-related AEs included dizziness (49%), dysgeusia (46%), paresthesias (29%), constipation (19%), fatigue (18%), nausea (11%), and anemia (11%). 4 DLTs were observed at ≥240mg/day: 1 grade 3 (Gr3) dyspnea/hypoxia, 2 Gr3 and 1 Gr2 dizziness. 31 of 72 pts had ROS1+ NSCLC by local testing (FISH, n=20; NGS, n=11) with 1 pt determined as ROS1-negative by central NGS. Antitumor activity in ROS1+ NSCLC has been observed at ROS1 dose levels 40mg QD-160mg BID per investigator assessment, with the best ORR 70% for TKI-naïve and 11% for TKI-refractory pts (17% for 1 prior TKI crizotinib, n=12) (Table). Two crizotinib-resistant pts with G2032R achieved durable cPR and cSD, respectively. Ongoing blinded independent review identified 7 evaluable pts with target CNS lesions at baseline; the intracranial best ORR was 43% (3 cPR, 1 PR*). Updated efficacy data and ctDNA biomarker analyses will be presented. Ropotrectinib is well tolerated and demonstrates promising activity in pts with advanced ROS1+ NSCLC, including TKI-naïve and TKI-refractory pts. RP2D has not yet been achieved. These Phase 1 data warrant further clinical testing of ropotrectinib in ROS1+ NSCLC.