ASH 2025 | PROMise trial update: OPN-2853 plus rux in advanced MF with inadequate response to rux alone

We’ve been running the PROMise study in the UK for a number of years now. This is a study that’s examining patients with myelofibrosis who have had a suboptimal response to standard treatment with ruxolitinib, defined as a residual splenomegaly of 5 centimeters. What we’re testing in that study is the safety and efficacy of adding in an additional treatment with a BET inhibitor called OPN-2853. So for the first part of the study, we wanted to establish the safe dose level, which we’ve now established as 80 milligrams in combination with ruxolitinib at various different dose levels. And now we’re extending the cohort. In fact, the study has finished recruiting. And this is an interim analysis that shows some preliminary efficacy data, which looks really encouraging, I think. So we’re seeing very impressive spleen response rates as measured by palpation and by ultrasound. And we’re also seeing really quite substantial symptom improvement with this drug. One important thing with this drug is it’s got quite distinct PK characteristics. So it’s continuous dosing unlike other BET inhibitors. So we think the combination is safe. We’ve established that clearly. We’ve established the dose level. And we’ve got really encouraging signs of efficacy in this second line setting where patients have a major unmet need for new treatment.

This transcript is AI-generated. While we strive for accuracy, please verify this copy with the video.