Spruce Biosciences is a clinical-stage company developing TA-ERT (tralesinidase alfa), an enzyme replacement therapy delivered into the brain for Sanfilippo syndrome type B (MPS IIIB), a fatal childhood disease with no approved treatment.
Spruce's case rests on TA-ERT, a weekly enzyme replacement therapy given into the brain's fluid spaces for MPS IIIB, which lowered heparan sulfate in cerebrospinal fluid in uncontrolled studies. Spruce plans a BLA in the fourth quarter of 2026 for accelerated approval on that biomarker as a surrogate endpoint, after what it called positive pre-BLA meetings with FDA. The submission has slipped from the first quarter of 2026, and cash should last into the second half of 2027.
Thesis checklist
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Why it is in this state
The evidence, what would weaken it and the source filing
Why it is in this state
The evidence, what would weaken it and the source filing
Why it is in this state
The evidence, what would weaken it and the source filing
Next decision point
Tests: BLA submitted in the fourth quarter of 2026
Does Spruce submit a complete BLA in the fourth quarter that FDA accepts for review?
Strong, inconclusive and weak outcomes
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Price and material events
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Spruce plans to submit a BLA for TA-ERT in MPS IIIB in the fourth quarter of 2026, seeking accelerated approval on a spinal-fluid biomarker after positive pre-BLA meetings with FDA
Sanfilippo syndrome type B BLA planned on surrogate-endpoint data; FDA's accelerated approval decision determines everything
Tralesinidase alfa's BLA for MPS IIIB tests whether six-year surrogate endpoint data is sufficient for accelerated approval in a disease with no approved therapy
TA-ERT's BLA for MPS IIIB tests whether CSF heparan sulfate normalization satisfies FDA's accelerated approval standard for a disease with no approved therapy
About this history: every entry shows when the Thesis moved and what it said. The reasoning behind each move (the evidence, the analysis and the source filing) and the earnings write-ups are part of a subscription.
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Cash: Market-data provider estimate; measurement period unavailable.
Debt: Market-data provider estimate; a complete comparable filing balance is unavailable.
Quarterly burn: Estimated from trailing free cash flow; measurement period unavailable.
Net cash and estimated runway require verified matching measurement periods. Missing debt components are not assumed to be zero.
Runway: No underlying guidance available.