Primary Risk Drivers
Below is a snapshot of domains that materially influence the MARA Rating.
Clinical effectiveness
The clinical effectiveness of avapritinib is based on two single-arm trials (PATHFINDER and EXPLORER) which suggest it increases the time before disease progression and overall survival. However, the absence of direct comparisons with standard treatments like midostaurin and cladribine introduces uncertainty regarding its relative efficacy. The indirect treatment comparisons indicate potential benefits, but the lack of Phase 3 evidence limits the strength of the conclusions.
Cost effectiveness
The cost-effectiveness analysis indicates that avapritinib’s ICER is within acceptable thresholds for Healthcare resources, estimated to be below £30,000 per QALY gained. This suggests that it provides a good value proposition relative to its benefits, especially considering the rarity of the condition and the unmet need.
Quality of life
Patient experts reported significant improvements in quality of life due to reduced symptoms and hospital admissions associated with avapritinib treatment. The evidence suggests that avapritinib has a positive impact on daily functioning, although specific validated HRQoL measures were not extensively detailed in the trials.
Supporting Domains
Safety and Adverse Effects
Avapritinib has a favorable safety profile with mostly mild to moderate adverse events reported. Patient experts noted that it causes fewer intolerable side effects compared to midostaurin, which is significant for patient adherence and quality of life.
Comparator Selection
The trials did not include direct comparisons with standard treatments, which limits the robustness of the evidence. While midostaurin and cladribine were identified as relevant comparators, the reliance on indirect comparisons raises concerns about the validity of the findings.
Patient Population and Subgroups
The trials included a representative population of patients with advanced systemic mastocytosis, although the rarity of the condition limits the generalizability of the findings. Subgroup analyses were mentioned, but further exploration could enhance understanding of treatment effects across different demographics.
Care Pathway Integration
Avapritinib can be integrated into existing treatment pathways with minor adjustments. It is positioned as a second-line treatment following midostaurin, which aligns with current clinical practices and does not require significant changes to healthcare delivery.
Resource Use and Cost Implications
The economic model suggests that avapritinib has a manageable budget impact, especially considering the potential for reduced hospital admissions and improved patient outcomes. The overall resource use is expected to be justifiable given the benefits.
Evidence Quality and Robustness
The evidence base is primarily derived from single-arm trials, which introduces limitations in terms of robustness and potential biases. While the trials were well-conducted, the lack of comparative data necessitates caution in interpreting the results.
Uncertainty, Sensitivity, and Broader Impacts
There are notable uncertainties regarding the long-term outcomes and the extrapolation of survival data. The committee acknowledged these uncertainties but also recognized the context of the rare disease and the potential for avapritinib to address significant unmet needs.
