Primary Risk Drivers
Below is a snapshot of domains that materially influence the MARA Rating.
Clinical effectiveness
Mavacamten demonstrated a clear clinical advantage over standard care in the pivotal EXPLORER-HCM trial, achieving its primary endpoint with statistically significant improvements in both NYHA class and peak oxygen consumption. Specifically, 37% of patients on mavacamten reached the primary endpoint compared to 17% on placebo (p=0.0005). Additionally, the VALOR-HCM trial supports its efficacy in delaying the need for invasive surgery, indicating a substantial therapeutic impact.
Cost effectiveness
The cost-effectiveness analysis indicates that mavacamten’s ICER is within the acceptable range for Healthcare resources, with a revised base case ICER of £19,997 per QALY gained after accounting for the commercial arrangement. This suggests that while there is some uncertainty, the treatment is defensibly cost-effective under current assumptions.
Quality of life
The evidence indicates that mavacamten positively impacts HRQoL by alleviating symptoms associated with obstructive HCM, which significantly affect daily functioning and psychological well-being. Patient experts reported that the treatment helps restore the ability to engage in everyday activities, suggesting moderate but meaningful improvements in quality of life.
Supporting Domains
Safety and Adverse Effects
Mavacamten has an acceptable safety profile, with manageable adverse effects primarily related to heart function monitoring. The need for safety monitoring is acknowledged, but the overall adverse event profile is comparable to existing therapies, indicating good tolerability.
Comparator Selection
While mavacamten was compared to standard care, the exclusion of disopyramide as a comparator raises concerns about the robustness of the evidence. The committee noted that disopyramide is used in practice, and its absence from the analysis limits the comprehensiveness of the comparative effectiveness evaluation.
Patient Population and Subgroups
The trial population in EXPLORER-HCM is broadly representative of the intended patient population with symptomatic obstructive HCM. The inclusion of various subgroups, including those with and without sarcomere mutations, enhances the generalizability of the findings, although some uncertainty remains regarding efficacy across these subgroups.
Care Pathway Integration
Mavacamten is positioned as an adjunct to existing standard care, which facilitates its integration into current treatment pathways. The committee noted that while some adjustments may be necessary, the overall fit with existing practices is strong.
Resource Use and Cost Implications
The budget impact analysis suggests that mavacamten is manageable within Healthcare resources, particularly given the potential to avoid costly invasive procedures. The commercial arrangement further supports its economic viability, indicating a favorable resource use profile.
Evidence Quality and Robustness
The evidence base is supported by robust Phase 3 trial data (EXPLORER-HCM) and long-term safety data from the EXPLORER-LTE study. The trials are well-designed, with low bias risk, although some limitations in subgroup analyses were noted.
Uncertainty, Sensitivity, and Broader Impacts
There is notable uncertainty surrounding the economic modeling assumptions, particularly regarding mortality and disease progression rates. While the committee acknowledged the potential benefits of mavacamten, the high degree of uncertainty in these areas suggests that its use may be restricted under certain conditions.
