Givinostat — DMD-approved HDAC inhibitor identified as top SMA repurposing candidate
Cross-database analysis of FDA-approved drugs against the HDAC6 mechanism validated by Osseni et al. (Brain 2026) for SMA identifies Givinostat (Duvyzat, Italfarmaco) as the strongest immediate repurposing candidate. Givinostat is a non-selective HDAC class I + IIb inhibitor (HDAC1, HDAC3, HDAC6 pchembl 8.38) approved by the FDA on 21 March 2024 for Duchenne muscular dystrophy.
Why Givinostat is the strongest repurposing match
Mechanism alignment: Osseni et al. (Brain 2026) demonstrated that systemic HDAC6 inhibition combined with SMN-restoring antisense oligonucleotides strongly improves muscle strength, mass, function, and longevity in SMA mouse models. Givinostat directly engages HDAC6 with high affinity.
Adjacent disease validation: Duchenne muscular dystrophy and SMA share core muscle-wasting pathology. Givinostat's approval for DMD demonstrates that HDAC6-driven muscle benefit translates to human patients, not just preclinical models.
Established safety profile: Pediatric safety data exist from the EPIDYS Phase 3 trial (Mercuri et al., NEJM 2024). Pharmacokinetics, drug-drug interactions, and adverse event profile are characterized in patients aged 6 years and older.
Commercial availability: As an approved drug, Givinostat is available for investigator-initiated trials and physician-led off-label exploration in the SMA context, subject to ethical and regulatory frameworks.
Caveats and next steps
Givinostat in DMD is a monotherapy on top of standard corticosteroid background. The Osseni mouse data specifically tested HDAC6 inhibition combined with SMN-restoring ASO — the relevant clinical analogue is Givinostat plus existing risdiplam, nusinersen, or onasemnogene abeparvovec. No clinical data yet exist for this specific combination in SMA patients.
Recommended next steps:
- Investigator-initiated Phase 2 pilot in SMA patients on stable SMN-restoring therapy
- In vitro validation in SMA patient-derived myotubes (replicating the Osseni cell-culture model)
- Pharmacovigilance review of cardiac and bone marrow effects in pediatric SMA population
Other approved HDAC6 binders identified
Cross-DB analysis also surfaced Panobinostat (Farydak, multiple myeloma, HDAC6 pchembl 8.82), Belinostat (Beleodaq, T-cell lymphoma, 7.82), Vorinostat (Zolinza, cutaneous T-cell lymphoma, 7.00), and Romidepsin (Istodax, 6.10) as approved HDAC inhibitors with HDAC6 affinity. These oncology drugs have less favorable safety profiles for chronic muscle-disease use compared to Givinostat's DMD-specific approval.
Source: Internal cross-DB analysis 2026-05-08, integrating Osseni et al. (Brain 2026), FDA Duvyzat approval (21 March 2024), and Mercuri et al. (NEJM 2024) EPIDYS trial data.