ASCO: Turning Point shares slide on 82% NSCLC ORR

Turning Point Therapeutics’ update on repotrectinib in non-small cell lung cancer showed more than four-fifths of patients responded to the tyrosine kinase inhibitor (TKI), but its stock fell 10%.

Turning Point, fresh from an IPO, focused its update on the 82% objective response rate (ORR) in TKI-naive ROS1+ patients. All three patients with brain metastases experienced intracranial responses and remain in partial responses, suggesting repotrectinib may have an edge over older NSCLC drugs that are unable to penetrate the brain in sufficient volumes to treat tumors.

The response rate among patients previously treated with TKIs such as Pfizer’s Xalkori was lower but still potentially competitive given the rate of resistance in this population. Of the 11 TKI pretreated patients who received 160 mg or more of repotrectinib a day, six responded, resulting in an ORR of 55%.

As previously reported by Turning Point, four trial subjects have died over the course of the trial. One death may be related to its drug. The biotech shared more details of the death in a SEC filing.

“The fourth grade 5 TEAE (treatment emergent adverse event) involved a patient with ALK+ NSCLC and a past medical history of diabetes, obesity and hypertension who was dosed at 240 mg QD (once daily) of repotrectinib and experienced a grade 5 event of sudden death on day 10 of cycle 1, which we determined to be possibly related to study treatment,” Turning Point wrote.

Over the course of the trial, Turning Point has reported two dropouts triggered by drug-related grade 3 events and seen a small number of dose-limiting toxicities related to dyspnea and dizziness. 

Turning Point is pushing ahead. Work to finalize the recommended dose is ongoing, beyond which Turning Point plans to move into the registrational portion of its phase 2 trial. The plan is to start the registrational part of the trial in the second half of the year. Turning Point is also gearing up to start three other clinical trials.

Editor's note: This article was updated to clarify that Turning Point previously reported the patient deaths.