FIREFISH Parts 1 and 2: 24-month safety and efficacy of risdiplam in infants with Type 1 SMA

Topic:

Clinical Trials

Poster Number: Virtual

Author(s):

Basil Darras, MD, Department of Neurology, Boston Children’s Hospital, Odile Boespflug-Tanguy, Hôpital Armand Trousseau; Université de Paris, UMR 1141, NeuroDiderot, John Day, MD, PhD, Stanford University, Nicolas Deconinck, MD, Centre de Référence Neuromusculaire and Paediatric Neurology Department, Hôpital Universitaire des E, Andrea Klein, University Children's Hospital Basel; Inselspital, University of Bern, Riccardo Masson, MD, Fondazione IRCCS Istituto Neurologico Carlo Besta, Maria Mazurkiewicz-Bełdzińska, Department of Developmental Neurology, Medical University of Gda?sk, Eugenio Mercuri, Paediatric Neurology and Centro Clinico Nemo, Catholic University and Policlinico Gemelli, Fondazion, Kristy Rose, Paediatric Gait Analysis Service of New South Wales, The Children’s Hospital at Westmead, Laurent Servais, I-Motion Institute, Hôpital Armand Trousseau, Dmitry Vlodavets, Russian National Research Medical University, Hui Xiong, Department of Pediatrics, Peking University First Hospital, Edmar Zanoteli, Department of Neurology, Faculdade de Medicina, Universidade de São Paulo (FMUSP), Angela Dodman, Pharma Development Neurology, F. Hoffmann-La Roche Ltd, Muna El-Khairi, Roche Products Ltd, Eleni Gaki, Roche Products Ltd, Marianne Gerber, MD, Pharma Development, Safety, F. Hoffmann-La Roche Ltd, Ksenija Gorni, MD, PDMA Neuroscience and Rare Disease, F. Hoffmann-La Roche Ltd, Heidemarie Kletzl, Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Giovanniu Baranello, MD, Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, UK.

Background
Spinal muscular atrophy (SMA) is a severe, progressive neuromuscular disease caused by reduced levels of survival of motor neuron (SMN) protein due to deletions and/or mutations of the SMN1 gene. A second gene, SMN2, produces only low levels of functional SMN protein. Risdiplam (EVRYSDI®) is a centrally and peripherally distributed, oral SMN2 pre?mRNA splicing modifier that has been approved by the FDA for the treatment of patients with SMA aged 2 months and older.

FIREFISH (NCT02913482) is a multicenter, open-label, two-part study of risdiplam in infants with Type 1 SMA and two SMN2 gene copies (inclusion criteria 1–7 months old at enrollment). Part 1 assesses the safety, tolerability and pharmacokinetics/pharmacodynamics of risdiplam dose levels (low-dose cohort, n=4; high-dose cohort, n=17). The pivotal Part 2 (N=41) assesses the efficacy and safety of risdiplam at the dose selected from Part 1.

Objective
To determine the efficacy and safety of risdiplam in infants with Type 1 SMA treated for 24 months during Parts 1 and 2 of the FIREFISH study.

Results
Previously we presented pooled safety and efficacy data from 58 infants in FIREFISH Part 1 (high-dose cohort, n=17) and Part 2 (N=41) who had received risdiplam treatment for ?12 months (data-cut: 14 November 2019). At Month 12, 88% (51/58) of infants were alive and did not require permanent ventilation and 57% (33/58) scored ?40 on the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders, showing improvements in motor function. Infants also achieved motor milestones, including sitting without support, standing with support and bouncing (assessed by the Hammersmith Infant Neurological Examination, Module 2), that are not observed in the natural history of Type 1 SMA. There were no treatment-related adverse events leading to withdrawal after 12 months of treatment.

Pooled FIREFISH safety and efficacy data will be presented for 58 infants who received risdiplam for ?24 months.

Conclusions
The safety and efficacy of risdiplam are consistent between FIREFISH Parts 1 and 2. Both Parts 1 and 2 are ongoing globally and will provide further data on the long-term efficacy and safety of risdiplam in infants with Type 1 SMA.