Safety and efficacy of risdiplam in patients with type 1 spinal muscular atrophy (FIREFISH part 2): secondary analyses from an open-label trial.

BACKGROUND: Risdiplam is an orally administered therapy that modifies pre-mRNA splicing of the survival of motor neuron 2 (SMN2) gene and is approved for the treatment of spinal muscular atrophy. The FIREFISH study is investigating the safety and efficacy of risdiplam in treated infants with type 1 spinal muscular atrophy versus historical controls. The primary endpoint of part 2 of the FIREFISH study showed that infants with type 1 spinal muscular atrophy attained the ability to sit without support for at least 5 s after 12 months of treatment. Here, we report on the safety and efficacy of risdiplam in FIREFISH part 2 over 24 months of treatment. METHODS: FIREFISH is an ongoing, multicentre, open-label, two-part study. In FIREFISH part 2, eligible infants (aged 1-7 months at enrolment, with a genetically confirmed diagnosis of spinal muscular atrophy, and two SMN2 gene copies) were enrolled in 14 hospitals in ten countries across Europe, North America, South America, and Asia. Risdiplam was orally administered once daily at 0·2 mg/kg for infants between 5 months and 2 years of age; once an infant reached 2 years of age, the dose was increased to 0·25 mg/kg. Infants younger than 5 months started at 0·04 mg/kg (infants between 1 month and 3 months old) or 0·08 mg/kg (infants between 3 months and 5 months old), and this starting dose was adjusted to 0·2 mg/kg once pharmacokinetic data were available for each infant. The primary and secondary endpoints included in the statistical hierarchy and assessed at month 12 have been reported previously. Here we present the remainder of the secondary efficacy endpoints that were included in the statistical hierarchy at month 24: the ability to sit without support for at least 30 s, to stand alone, and to walk alone, as assessed by the Bayley Scales of Infant and Toddler Development, third edition gross motor subscale. These three endpoints were compared with a performance criterion of 5% that was defined based on the natural history of type 1 spinal muscular atrophy; the results were considered statistically significant if the lower limit of the two-sided 90% CI was above the 5% threshold. FIREFISH is registered with ClinicalTrials.gov, NCT02913482. Recruitment is closed; the 36-month extension period of the study is ongoing. FINDINGS: Between March 13 and Nov 19, 2018, 41 infants were enrolled in FIREFISH part 2. After 24 months of treatment, 38 infants were ongoing in the study and 18 infants (44% [90% CI 31-58]) were able to sit without support for at least 30 s (p<0·0001 compared with the performance criterion derived from the natural history of untreated infants with type 1 spinal muscular atrophy). No infants could stand alone (0 [90% CI 0-7]) or walk alone (0 [0-7]) after 24 months of treatment. The most frequently reported adverse event was upper respiratory tract infection, in 22 infants (54%); the most common serious adverse events were pneumonia in 16 infants (39%) and respiratory distress in three infants (7%). INTERPRETATION: Treatment with risdiplam over 24 months resulted in continual improvements in motor function and achievement of developmental motor milestones. The FIREFISH open-label extension phase will provide additional evidence regarding long-term safety and efficacy of risdiplam. FUNDING: F Hoffmann-La Roche.

Natural history of Type 1 spinal muscular atrophy: a retrospective, global, multicenter study.

BACKGROUND: ANCHOVY was a global, multicenter, chart-review study that aimed to describe the natural history of Type 1 spinal muscular atrophy (SMA) from a broad geographical area and provide further contextualization of results from the FIREFISH (NCT02913482) interventional study of risdiplam treatment in Type 1 SMA. METHODS: Data were extracted from medical records of patients with first symptoms attributable to Type 1 SMA between 28 days and 3 months of age, genetic confirmation of SMA, and confirmed survival of motor neuron 2 copy number of two or unknown. The study period started on 1 January 2008 for all sites; study end dates were site-specific due to local treatment availabilities. Primary endpoints were time to death and/or permanent ventilation and proportion of patients achieving motor milestones. Secondary endpoints included time to initiation of respiratory and feeding support. RESULTS: Data for 60 patients from nine countries across Asia, Europe and North and South America were analyzed. The median age (interquartile range [IQR]) for reaching death or permanent ventilation was ~ 7.3 (5.9-10.5) months. The median age (IQR) at permanent ventilation was ~ 12.7 (6.9-16.4) months and at death was ~ 41.2 (7.3-not applicable) months. No patients were able to sit without support or achieved any level of crawling, standing or walking. INTERPRETATION: Findings from ANCHOVY were consistent with published natural history data on Type 1 SMA demonstrating the disease's devastating course, which markedly differed from risdiplam-treated infants (FIREFISH Part 2). The results provide meaningful additions to the literature, including a broader geographical representation.

Pharmacokinetics, safety, and tolerability of siponimod (BAF312) in subjects with severe renal impairment: A single-dose, open-label, parallel-group study
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OBJECTIVE: To investigate the pharmacokinetics (PK), safety, and tolerability of siponimod and selected inactive metabolites (M3 and M5) in subjects with varying degrees of renal impairment (RI) compared to demographically matched healthy subjects (HS). METHODS: The study enrolled subjects with severe RI (n = 8) and matched HS (n = 8). Subjects with moderate and mild RI were to be enrolled only if interim analysis showed ≥ 50% increase in maximum plasma concentration (Cmax) or area under the curve (AUC) of total and/or unbound siponimod in severe RI subjects vs. HS. All subjects received a single oral dose of siponimod 0.25 mg on day 1; PK and safety were evaluated during the follow-up (~ 13 days). RESULTS: PK of siponimod was marginally affected in severe RI subjects vs. HS: Cmax decreased by 8%, and AUClast and AUCinf increased by 23% and 24%, respectively; half-life (37 vs. 26 hours) and systemic clearance (2.9 vs. 3.4 L/h) were comparable. Siponimod plasma unbound (u) fraction at 4 hours post-dose was similar between the two groups (range: 0.0172 - 0.0550%). Cmax(u) was comparable while AUClast(u) and AUCinf(u) were increased by 33% compared to HS. M3 exposure was similar (Cmax decreased by 9%; AUClast and AUCinf increased by 11%) and M5 exposure was slightly lower (Cmax decreased by 26%; AUClast decreased by 16%) in subjects with severe renal impairment (RI) compared with matched HS. No adverse events were reported during this study. CONCLUSIONS: Changes in the plasma exposure of total and unbound siponimod and metabolites M3 and M5 were not considered to be clinically relevant. Further to severe RI, investigation of PK in subjects with mild and moderate RI was not warranted.
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Pharmacokinetics, safety, and tolerability of siponimod (BAF312) in subjects with different levels of hepatic impairment: a single-dose, open-label, parallel-group study
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OBJECTIVE: To assess the pharmacokinetics (PK), safety, and tolerability of siponimod and major metabolites in subjects with mild, moderate, and severe hepatic impairment (HI) compared with demographically-matched healthy subjects (HS). METHODS: This open-label, parallel-group study enrolled 40 subjects (each HI group, n = 8; HS group, n = 16). A staged design was employed starting with the enrollment of subjects with mild HI, followed by those with moderate and severe HI. All subjects received single oral doses of 0.25 mg siponimod on day 1; PK and safety data were collected during the 21-day follow-up. RESULTS: All subjects had similar baseline characteristics and completed the study. No significant differences were observed in the plasma exposure of siponimod in mild, moderate, and severe HI groups vs. HS: Cmax changed by 16%, -13%, and -16%; AUC by 5%, -13%, and 15%, respectively. The unbound siponimod PK parameters vs. HS were similar in the mild HI, and increased in the moderate (Cmax, 15%; AUC, 17%) and severe HI groups (Cmax, 11%; AUC, 50%). Exposure of M3 and M5 also showed 2- to 5-fold increase, particularly in the moderate and severe HI groups vs HS. There were no clinically-relevant safety findings. CONCLUSIONS: Single oral doses of 0.25 mg siponimod were well tolerated, and HI did not significantly alter exposure to siponimod. Increase in the M3 and M5 metabolites requires further evaluation. These results do not warrant any dose adjustments of siponimod in subjects with HI.
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Intravenous Dosing as an Alternate Approach to Safely Achieve Supratherapeutic Exposure for Assessments of Cardiac Repolarization: A Randomized Clinical Trial with Mavoglurant (AFQ056).

PURPOSE: The conduct of thorough QTc (TQT) studies is often challenging with compounds that are characterized by limited tolerability in healthy individuals. This is applicable to several central nervous system drugs, including mavoglurant acting as a selective allosteric modulator of metabotropic glutamate receptor 5. This TQT study describes the use of a single intravenous dosing regimen as an alternate approach allowing for sufficiently high Cmax values while controlling tolerability. METHODS: This study was a randomized, placebo- and active-controlled, 4-period, crossover, TQT study composed of 2 sequential phases. In the pilot phase, the safety and tolerability profile of 10-minute infusions of 25, 37.5, and 50 mg of mavoglurant was assessed in 36 healthy individuals. In the TQT phase, individuals received in random sequence single intravenous doses of mavoglurant (25 and 50 mg) and placebo and an oral dose of moxifloxacin (400 mg). FINDINGS: Mavoglurant was well tolerated up to a single intravenous dose of 50 mg, and supratherapeutic Cmax values were achieved that were approximately 2-fold higher than at the multiple maximum tolerated dose and more than 3-fold higher relative to therapeutic plasma concentrations. The upper bound of the 2-sided 90% CI of Fridericia-corrected placebo- and baseline-adjusted QTc intervals (QTcFs) did not exceed 10 milliseconds at any postdose time point for both mavoglurant doses. The pharmacokinetic and pharmacodynamic analysis confirmed the lack of an association between mavoglurant plasma concentrations and ΔΔQTcF data over the entire range of plasma concentration data at 25 and 50 mg of mavoglurant. An outlier analysis revealed no individuals with newly identified QTcF intervals >480 milliseconds or any QTcF prolongations >60 milliseconds compared with baseline in any of the treatment groups. Hence, the lack of any clinically relevant QTc prolongation was found for therapeutic and supratherapeutic single intravenous doses of 25 and 50 mg of mavoglurant. IMPLICATIONS: This TQT study describes the use of single intravenous dosing as an alternate approach to achieve supratherapeutic plasma concentrations as required per the International Council for Harmonisation E14 guideline with compounds characterized by exposure related tolerability limitations. The increased Cmax/AUC ratio compared with conventional oral dosing may contribute to a reduced incidence of adverse events that appear more related to overall exposure.