Pro15 Cost-Effectiveness of Nusinersen and Onasemnogene Abeparvovec for Infantile-Onset Spinal Muscular Atrophy (Type I Sma) in the Us

Abstract

To assess the 5-year budget impact of single-dose gene-replacement therapy AVXS-101 (onasemnogene abeparvovec) versus current standard-of-care (nusinersen) in US patients with Spinal Muscular Atrophy Type 1 (SMA1). Methods: We developed a multi-state survival Markov model with health-state transitions based on milestone attainment (sitting, walking) from published clinical trials. Survival benefit was estimated using long-term survival data from sitting and walking SMA patients and natural history data. We used published sources to estimate the size of eligible population and expected market share of each therapy before and after AVXS-101 approval. Costs related to drug acquisition and administration, expected hospital markups, adverse events and SMA care were sourced from published claims analysis data, literature, and expert opinion.

Systematic Literature Review to Assess Economic Evaluations in Spinal Muscular Atrophy (SMA)

“…The nine publications included in this SLR comprised four conference abstracts [53][54][55][56], two peer-reviewed, original research articles [57,58] and three distinct HTA submissions: one submission to the Canadian Agency for Drugs and Technologies in Health (CADTH) published in 2018 [59], one submission (TA588) to the UK NICE published in 2018 [60] and one submission to the US ICER Group published in 2019 [61]. The CADTH [59], NICE [60] and US ICER Group [61] HTA submissions comprised economic models from studies conducted in Canada, the UK and the US, respectively.…”

“…There was some overlap between the identified published economic evaluations and HTA submissions: the published analysis by Zuluaga-Sanchez et al 2019 [58] included a similar model to that submitted to NICE [60] and to CADTH [59]. Furthermore, the published analysis by Thokala et al 2019 [54] included the model submitted to the US ICER Group [61]. All nine publications (including HTA submissions, abstracts and full manuscripts) that met the eligibility requirements of the literature search contained unique data and were therefore considered as discrete publications for the review.…”

“…Six economic evaluations, published as conference abstracts or journal articles, represented five studies conducted in the US [53][54][55][56][57] and one published economic evaluation reported a study conducted in Sweden [58]. Two publications based on a study conducted by the same research group in the US were published as an abstract [53] and a full-text publication [57].…”

“…Two publications based on a study conducted by the same research group in the US were published as an abstract [53] and a full-text publication [57]. The evaluations considered patients with early infantile-onset SMA (most likely to develop Type 1 or Type 2 SMA) (n = 4) [53][54][55]57], later-onset SMA (n = 1) [56] and both infantile-and later-onset SMA (n = 1) [58]. Treatment comparisons considered across the six published economic evaluations included nusinersen versus SOC [54][55][56], nusinersen + SOC versus SOC [58], onasemnogene abeparvovec versus SOC [54], onasemnogene abeparvovec compared with nusinersen + SOC [57] and onasemnogene abeparvovec compared with nusinersen as the SOC [53].…”

“…The evaluations considered patients with early infantile-onset SMA (most likely to develop Type 1 or Type 2 SMA) (n = 4) [53][54][55]57], later-onset SMA (n = 1) [56] and both infantile-and later-onset SMA (n = 1) [58]. Treatment comparisons considered across the six published economic evaluations included nusinersen versus SOC [54][55][56], nusinersen + SOC versus SOC [58], onasemnogene abeparvovec versus SOC [54], onasemnogene abeparvovec compared with nusinersen + SOC [57] and onasemnogene abeparvovec compared with nusinersen as the SOC [53]. An incremental cost per quality-adjusted life-year (QALY) gained was reported in all six publications [53][54][55][56][57][58].…”