Clinical Experience with Midostaurin in Advanced SM

Transcript:Cem Akin, MD: To give you an example of a specific patient, I followed a patient for about 2 or 3 years who had longstanding indolent mastocytosis who then progressed into aggressive systemic mastocytosis, developed anemia, and had to be transfused. We initially managed that patient with cladribine, but then she developed neutropenia and thrombocytopenia that did not allow us to give more cycles of cladribine. She did respond well to cladribine initially, but then there were no treatment options for her because she also had the D816V mutation.

So, then we turned to midostaurin. We enrolled her on a compassionate trial of midostaurin, and she has done extremely well on midostaurin with the bone marrow mast cell burden decreasing, tryptase decreasing, and her symptomatically feeling better. I believe she’s still on that medication.

I think, looking into the future, if or when midostaurin gets approved, it will replace cladribine and interferon-alpha as a first-line treatment option in patients with advanced disease due to its very favorable toxicity profile, tolerability, ease of use, and efficacy.

Richard M. Stone, MD: For patients who have this disease, it’s a huge boon. I’ve seen patients really benefit from this. I have a patient, for example, who had severe bone pain and went to the emergency room requiring narcotics every couple of months, and now he doesn’t do that anymore. He has a little nausea and vomiting from the midostaurin; he’s on compassionate use midostaurin. So, it’s just one example of the benefit that people can get from this drug. It’s a huge drug for a rare disease, but a very important drug in that respect.

Patients with aggressive systemic mastocytosis who have at least one C-finding and one organ issue, such as severe pruritus, bone pain, bone marrow failure, major liver abnormalities, or GI tract problems, would be candidates for this drug. People have experienced important symptom relief. Patients who have severe bone pain, who have required narcotics, no longer require them. Patients who’ve had bad cutaneous symptoms have gotten better, so there are a lot of patients who have benefitted from it already. The duration of response is appreciable, not forever, but we need to study resistance mechanisms and whatnot. I think it’s going to be a great advantage to have in the therapeutic armamentarium for a disease that doesn’t have a lot of great drugs right now.

Transcript Edited for Clarity