SPI2
(2020)Objective
To determine whether high-dose pharmaceutical-grade biotin (MD1003, 300 mg/day) slows disability progression in progressive MS
Study Summary
• No significant differences in any secondary endpoint (EDSS progression, T25FW, 9-HPT, CGI, MRI); landmark negative trial definitively disproving the biotin hypothesis after promising phase 2 results (MS-SPI)
Intervention
MD1003 (pharmaceutical-grade biotin) 100 mg three times daily (300 mg/day) vs matching placebo
Inclusion Criteria
Age 18-65, SPMS or PPMS, EDSS 4.5-7.0, documented disability progression in prior 2 years, no relapse in 3 months
Study Design
Arms: MD1003 300 mg/day vs Placebo
Patients per Arm: MD1003: 432, Placebo: 210
Outcome
• No differences in EDSS progression, T25FW, 9-HPT, CGI, or MRI outcomes
• Landmark negative trial disproving biotin hypothesis after promising MS-SPI phase 2 results
Bottom Line
MD1003 (high-dose biotin 300 mg/day) did NOT improve disability in progressive MS. The primary endpoint -- confirmed disability improvement at 15 months -- was not significantly different between MD1003 and placebo (12.0% vs 9.0%, p=0.38). No secondary endpoints were positive. This definitive negative trial disproved the biotin hypothesis for progressive MS that had been generated by the promising but methodologically limited MS-SPI phase 2/3 trial.
Major Points
- Primary endpoint negative: confirmed disability improvement 12.0% MD1003 vs 9.0% placebo (p=0.38)
- No differences in any secondary endpoint: EDSS progression, T25FW, 9-HPT, CGI, brain volume, or neurofilament light
- Definitively disproved the biotin hypothesis: the earlier MS-SPI trial (2016) had reported 12.6% vs 0% improvement, generating substantial enthusiasm
- The higher-than-expected placebo response (9.0% improved) contributed to the negative result, suggesting the MS-SPI findings were partly due to chance or methodological limitations
- Biotin interfered with numerous laboratory assays (thyroid function, troponin, vitamin D), a safety concern identified during the trial
- 93% of patients had SPMS and 7% PPMS; majority with EDSS 5.5-6.5
- Largest trial of high-dose biotin in progressive MS; definitively answered the question
Study Design
- Study Type
- Phase 3, multicenter, randomized, double-blind, placebo-controlled trial
- Randomization
- Yes
- Blinding
- Double-blind
- Sample Size
- 642
- Follow-up
- 15 months (primary assessment at 12 months, confirmation at 15 months)
- Centers
- 89
- Countries
- United States, Canada, United Kingdom, France, Germany, Italy
Primary Outcome
Definition: Proportion of patients with confirmed disability improvement at month 12 (sustained at month 15): EDSS decrease >=1 point (if baseline <=5.5) or >=0.5 (if baseline >=6.0), OR T25FW improvement >=20%
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| Placebo: 19/210 (9.0%) | MD1003: 52/432 (12.0%) | - | 0.38 (not significant) |
Limitations & Criticisms
- Failed to replicate the promising MS-SPI results (12.6% vs 0%), suggesting the earlier trial's findings were due to chance, unblinding, or methodological issues
- Higher-than-expected placebo improvement rate (9.0%) eroded statistical power, though this also suggests the MS-SPI 0% placebo rate was an anomaly
- 15-month follow-up may be insufficient for detecting neuroprotective effects in progressive MS
- Biotin interference with laboratory assays is a significant practical safety concern, potentially causing misdiagnosis (false thyroid results, missed troponin elevations)
- Industry-sponsored by MedDay Pharmaceuticals (biotin manufacturer)
- EDSS-based improvement endpoint has known floor/ceiling effects and poor sensitivity in the 6.0-7.0 range where most patients clustered
Citation
Cree BAC et al. Lancet Neurol. 2020;19(12):988-997. DOI: 10.1016/S1474-4422(20)30347-1