Nipocalimab (Imaavy)

Key Messages

• Canada’s Drug Agency (CDA-AMC) recommends that Imaavy not be reimbursed by public drug plans “as an add-on to standard therapy for the treatment of generalized myasthenia gravis in adult and adolescent patients aged 12 years and older who are anti-acetylcholine receptor or anti-muscle-specific tyrosine kinase antibody positive.”
• The Canadian Drug Expert Committee (CDEC) determined that it is uncertain whether Imaavy demonstrates acceptable clinical value versus appropriate comparators when used as an add-on to standard therapy for the treatment of generalized myasthenia gravis (gMG) in adult and adolescent patients with antiacetylcholine receptor (AChR) or antimuscle-specific tyrosine kinase (MuSK) antibody-positive disease. Appropriate comparators in the adult population refer to rituximab, efgartigimod alfa, ravulizumab, zilucoplan, and rozanolixizumab. Appropriate comparators in the adolescent population refer to IV immunoglobulin (IVIg), plasma exchange (PLEX), and rituximab. Given that Imaavy is expected to be an alternative treatment to the comparators, acceptable clinical value refers to at least comparable value versus the comparators relevant to each age group.
• Evidence from 1 clinical trial in adult patients with gMG showed that compared with placebo, treatment with Imaavy likely improves daily function, disease severity, and may improve health-related quality of life (HRQoL) at 22 to 24 weeks. However, it is uncertain whether the improvements are clinically meaningful. Further, there appears to be little to no clinically meaningful difference between Imaavy and placebo in the proportion of patients who had treatment response and fatigue. The evidence for the subgroup with anti-MuSK antibody-positive disease was uncertain due to the small number of patients enrolled in the trial.
• Evidence from 1 trial of 8 adolescents with gMG was highly uncertain due to small sample size and single-arm trial design.
• Evidence from 1 indirect treatment comparison (ITC) of adults with anti-AChR antibody-positive disease was associated with important methodological limitations that precluded CDEC from drawing firm conclusions regarding the comparative efficacy and safety of Imaavy versus efgartigimod alfa, ravulizumab, zilucoplan, and rozanolixizumab. Rituximab was also not included in the efficacy comparison. Additionally, no comparative evidence versus relevant comparators was submitted for adolescents and for the subpopulation with anti-MuSK antibody-positive disease.
• CDEC acknowledged a significant unmet need in adolescent patients and patients with anti-MuSK antibody-positive disease based on disease severity, limited treatment options, and potential challenges with evidence generation due to the rarity of gMG. However, CDEC was unable to determine that Imaavy addresses the significant unmet need with an acceptable level of certainty in clinical value based on the evidence reviewed. CDEC did not identify a significant unmet need in the adult population with anti-AChR antibody-positive disease given the availability of multiple advanced therapies.
• CDEC acknowledged that there is a significant unmet nonclinical need and health inequity, including geographic barriers or inequitable access to infusion services across Canada. However, the committee was unable to determine if Imaavy addresses this significant unmet nonclinical need and health inequity, since similar to many existing treatments, Imaavy is administered as an IV infusion and requires access to infusion centres or home infusion programs, which remain limited in many rural and remote regions.
• Based on all of the preceding considerations, CDEC recommended that Imaavy not be reimbursed.