NEW YORK – Repare Therapeutics on Wednesday said it aims to evaluate the PKMYT1 inhibitor lunresertib in a randomized Phase II study following a positive readout from the Phase I MINOTAUR trial.
In the trial, Repare is studying lunresertib in combination with FOLFIRI chemotherapy in 38 patients with genomically defined advanced solid tumors. The researchers saw promising signs of efficacy in heavily pretreated patients with tumors harboring CCNE1 amplifications and FBXW7 alterations. The overall response rate across tumor types, primarily digestive cancers, was 18.2 percent with four confirmed and two unconfirmed responses. Patients had a clinical benefit rate of 51.5 percent, and the circulating tumor DNA molecular response rate was 61 percent or 14 out of 23 evaluable patients. The drug combo was well tolerated and not more toxic than lunresertib or FOLFIRI alone.
"The encouraging tolerability and early antitumor efficacy data and the potential duration of treatment advantage of the combination of lunresertib plus FOLFIRI in this heavily pretreated patient population warrant further development in a randomized Phase II study," Maria Koehler, Repare executive VP and chief medical officer, said in a statement.
The Montreal-based company is also conducting clinical studies of lunresertib in the Phase I/Ib MYTHIC trial and its ATR kinase inhibitor camonsertib as a treatment for patients with certain tumor types in the Phase I/II TRESR trial.
Repare inked a deal with Foundation Medicine earlier this month to provide genomic profiling services for the MYTHIC trial and potentially develop a companion diagnostic for lunresertib.