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Systemic mastocytosis is a rare blood disorder caused by the build-up of too many abnormal mast cells, a type of white blood cell, in the skin and organs. Patients with advanced systemic mastocytosis have a low life expectancy and limited treatment options. This research aimed to compare the effectiveness of two recent and innovative treatments (called avapritinib and midostaurin) in extending life expectancy and decreasing mast cells and organ damage. As avapritinib and midostaurin were not investigated in the same clinical studies, it was necessary to compare the two treatments using the results from studies of each individual treatment. The published evidence used to support this comparison was systematically searched for and consisted of four clinical studies: the EXPLORER and PATHFINDER studies (investigating avapritinib) and D2201 and A2213 studies (investigating midostaurin). An indirect comparison between the studies was made that adjusted for differences in key patient characteristics. The results suggest that compared with midostaurin, avapritinib has the potential to extend life expectancy and decrease disease burden.

Introduction: For patients with generalized myasthenia gravis (gMG), the association between symptom severity, often measured with the Myasthenia Gravis Activities of Daily Living (MG-ADL) instrument, and utility values is unknown. Methods: Data was analyzed from the phase 3 ADAPT trial, which included adult patients with gMG randomly assigned to treatment with efgartigimod + conventional therapy (EFG + CT) or placebo + CT (PBO + CT). MG-ADL total symptom scores and the EQ-5D-5L, a measure of health-related quality of life (HRQoL), were collected biweekly up to 26 weeks. Utility values were derived from the EQ-5D-5L data with the United Kingdom value set. Descriptive statistics were reported for MG-ADL and EQ-5D-5L at baseline and follow-up. A normal identity-link regression model estimated the association between utility and the eight MG-ADL items. A generalized estimating equations (GEE) model was estimated to predict utility based on the patient’s MG-ADL score and treatment received. Results: A total of 167 patients (84 EFG + CT, 83 PBO + CT) contributed 167 baseline and 2867 follow-up measurements of MG-ADL and EQ-5D-5L. EFG + CT-treated patients experienced more improvements than PBO + CT-treated patients in most MG-ADL items and EQ-5D-5L dimensions, with the largest improvements observed in chewing, brushing teeth/combing hair, eyelid droop (MG-ADL); self-care, usual activities, mobility (EQ-5D-5L). The regression model indicated that individual MG-ADL items contributed differently to utility values, with the largest impact from brushing teeth/combing hair, rising from a chair, chewing, and breathing. The GEE model showed that each unit improvement in MG-ADL led to a statistically significant utility increase of 0.0233 (p < 0.001). In addition, a statistically significant improvement of 0.0598 (p = 0.0079) in utility was found for patients in the EFG + CT group compared to the PBO + CT group. Conclusion: Among patients with gMG, improvements in MG-ADL were significantly associated with higher utility values. MG-ADL scores alone were not sufficient to capture the utility gained from efgartigimod therapy.