Efficacy

Rydapt (Midostaurin) Efficacy in Leukemia

Rydapt, known generically as midostaurin, is a kinase inhibitor approved by the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with newly diagnosed acute myeloid leukemia (AML) that is FLT3 mutation-positive, as detected by an FDA-approved test, in combination with standard cytarabine and daunorubicin induction and cytarabine consolidation. The efficacy of Rydapt in this setting was demonstrated in a pivotal phase III clinical trial (RATIFY), which showed that patients who received Rydapt in combination with chemotherapy had a significant improvement in overall survival compared to those who received chemotherapy alone. The median overall survival was 74.7 months for patients treated with Rydapt plus chemotherapy, compared to 25.6 months for those receiving chemotherapy alone.

Furthermore, Rydapt is also approved for the treatment of adults with aggressive systemic mastocytosis (ASM), systemic mastocytosis with associated hematological neoplasm (SM-AHN), or mast cell leukemia (MCL). In these rare forms of leukemia, Rydapt has been shown to reduce the burden of mast cells and improve symptoms related to the disease. However, the rarity of these conditions means that the clinical trial data is limited, and the efficacy of Rydapt for these indications is based on overall response rate and duration of response.

Scemblix (Asciminib) Efficacy in Leukemia

Scemblix, with the generic name asciminib, is a newer medication that has been approved by the FDA for the treatment of adult patients with Philadelphia chromosome-positive chronic myeloid leukemia (CML) in chronic phase, who have received two or more prior lines of tyrosine kinase inhibitor (TKI) therapy, or who have the T315I mutation. The efficacy of Scemblix was established in two pivotal trials. In the ASCEMBL trial, patients with CML in chronic phase who were previously treated with two or more TKIs were randomized to receive either asciminib or bosutinib. The trial demonstrated that Scemblix led to a higher major molecular response (MMR) rate at 24 weeks compared to bosutinib (25.5% vs. 13.2%).

For patients with the T315I mutation, the efficacy of Scemblix was evaluated in a separate phase I trial. In this trial, a substantial proportion of patients achieved a hematologic response, and some achieved a cytogenetic response. The responses observed in the trial were durable, with some patients maintaining response for more than one year. The approval of Scemblix offers a new therapeutic option for patients with CML who have limited treatment options due to resistance or intolerance to prior TKI therapy.