Turning Point Therapeutics, Inc. announced updated interim findings from the ongoing TRIDENT-1 registrational study of lead drug candidate repotrectinib in patients with ROS1-positive TKI-naïve non-small cell lung cancer (NSCLC). In a total of 15 patients enrolled in the Phase 2 portion of the TRIDENT-1 study, the preliminary efficacy analysis showed the confirmed objective response rate (ORR) by physician assessment was 93% (95% CI: 68-100) and in 22 patients pooled from the Phase 1 (dosed at or above the Phase 2 dose) and Phase 2 portions, the confirmed ORR was 91% (95% CI: 71-99). The findings will be presented in a mini-oral presentation by Dr. Byoung Chul Cho, Division of Medical Oncology, Yonsei Cancer Center at Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea, at the International Association for the Study of Lung Cancer 2020 World Conference on Lung Cancer. Utilizing a Dec. 31, 2020 cutoff date, the TRIDENT-1 preliminary interim efficacy update includes 22 ROS1-positive TKI-naïve NSCLC patients pooled from the Phase 1 portion of the study (dosed at or above the Phase 2 dose) with patients from the Phase 2 portion who had at least two post-baseline scans. Responses for patients in the Phase 2 portion of the study were determined by physician assessment. The interim safety update includes a total of 185 patients from the Phase 1 and Phase 2 portions of the study utilizing an Oct. 30, 2020 cutoff date. 14 of 15 patients treated in the Phase 2 portion achieved a confirmed ORR of 93% (95% CI: 68-100). At the time of the data cut-off, the one non-responder remained on treatment and in stable disease with a 13% tumor reduction. In addition, one of the 14 patients in a partial response at the time of the data cutoff date has since achieved a confirmed complete response. Duration of response ranged from 1.3+ to 7.4+ months, and the duration of treatment ranged from 3.7+ to 10.9+ months with 14 of the 15 patients remaining on treatment. As of the cutoff date, one additional patient (not included in the confirmed ORR calculation) had an unconfirmed partial response and was on treatment awaiting a confirmatory scan. The company’s prior Phase 2 update with the data cutoff date of July 10, 2020 in 7 total patients, showed a confirmed ORR of 86% and a wider 95% confidence interval of 42 to 100. 20 of 22 patients pooled from Phase 1 and Phase 2 achieved a confirmed ORR of 91% (95% CI: 71-99). In the 7 patients from the Phase 1 portion dosed at or above the Phase 2 dose, duration of treatment ranged from 10.9 to 37.3 months with a median of 30.9 months, with four patients receiving treatment for longer than 30 months. Repotrectinib was generally well tolerated in 185 patients treated in the Phase 1 and Phase 2 portions of the study. Treatment-emergent adverse events (TEAE) found in greater than 15% of patients were dizziness (58%), dysgeusia (43%), constipation (32%), dyspnea (31%), fatigue (27%), paresthesia (25%), anemia (22%), nausea (20%), and muscular weakness (16%). There were four cases of Grade 3 dizziness (2%) and no cases of dizziness have led to treatment discontinuation. Dose modifications due to TEAEs were infrequent, including 18% that led to dose reduction and 9% that led to drug discontinuation. The majority of treatment related AEs (TRAEs) were Grade 1 or 2 and there were no Grade 4 or Grade 5 TRAEs.