Mariana Castells, MD, PhD: Safety Profile of Avapritinib in Pioneer Trial

Mariana Castells, MD, PhD, spoke with HCPLive in another interview regarding her team’s findings on avapritinib for indolent systemic mastocytosis (SM) in the PIONEER trial, specifically on future areas of interest for this research and on the safety profile.

Castells’s data had been presented at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2023 Annual Meeting in San Antonio, Texas.

She is known for her background as a professor at Harvard Medical School and as director of the Drug Hypersensitivity and Desensitization Center and the Mastocytosis Center at Brigham Women’s Hospital.

Castells went into a discussion about the study’s participant responses to avapritinib, specifically regarding the safety profile of the drug.

“So the majority of the side effects that were reported were very similar and, in fact, the severe side effects that were reported were more frequent in the placebo than in the treated group,” she explained. “The most frequent side effects that were found in our trial were grade 1 or grade 2, which is mild-to-moderate. And those were headache, nausea, peripheral edema, swelling, swelling around the eyes, or some dizziness.”

Castells also spoke about the potential effects of the drug on the condition.

“I can tell you that the patients have been found to have less spots in their skin, they have less gastrointestinal symptoms, they are less fatigued, they have less brain fog, they have less bone pain,” she said. “So overall, there's an improvement in the quality of life of those patients. So it has been shown really quickly in the first 24 weeks, and now we see a further improvement in 48 weeks.”

Finally, she discussed her plans for future research into the effects of avapritinib.

“We're looking at continuing to see the progress of the medication and continuing to see the potential side effects,” she explained, adding that they are in the third of 5 years for the trial.“And then and then we are having a conversation about who would be qualified for avapritinib. The patients that qualified for this study were patients who had pretty severe side effects despite the fact that they were on a lot of medications that were addressing their symptoms.”

Castells added that the team is interested in the topic of whether the drug can be used as a first-line therapy for those with SM.

“I think the next step is that everybody becomes comfortable with potential side effects, with continued improvement of symptoms,” she said. “And then trying to place avapritinib as the armamentarium, as a tool for the treatment of imbalances and mastocytosis patients as a first line tool.”

To learn more about the PIONEER trial findings discussed here, view the full interview above.

Castells has worked in either a consultancy or part of a paid advisory board of Cogent Biosciences in the time frame of the last 12 months.