Spruce Biosciences Inc (NASDAQ:SPRB) saw its stock move higher in after-hours trade on Monday, rising 3.2% following the release of long-term clinical findings for its investigational therapy in Sanfilippo Syndrome Type B and the start of analyst coverage with a favourable rating.
The data were presented at the 18th International MPS & Related Lysosomal Diseases Symposium and focused on tralesinidase alfa, an enzyme replacement therapy (TA-ERT) being developed for MPS IIIB, a fatal lysosomal storage disorder for which no approved therapies currently exist. The presentation included an analysis of 22 patients with follow-up extending up to six years.
According to the company briefing, TA-ERT produced a rapid and durable normalization of cerebrospinal fluid heparan sulfate non-reducing end (CSF HS-NRE), a surrogate endpoint the researchers said is reasonably likely to predict clinical benefit. Alongside biomarker changes, the analysis reported stabilization of cognitive function as measured by the Bayley-III Cognitive Raw Score when compared with declines observed in untreated natural history patients.
Additional findings presented indicated stabilization of receptive and expressive communication, and of fine and gross motor skills, relative to declines documented in untreated natural history cohorts. The therapy also reportedly stabilized cortical gray matter volume and returned liver and spleen volumes to normal ranges.
Market attention was reinforced when Jones Trading analyst Catherine Novack initiated coverage on Spruce Biosciences with a buy rating and set a price target of $135. The initiation highlighted the firm's view of a potential approval for TA-ERT in mid-2027 and the likelihood of near-term cash consideration tied to a priority review voucher estimated at approximately $180 million upon approval.
On the company's balance sheet, Spruce reported pro forma cash of $107.3 million as of April 30, 2026. The company indicated that this cash position provides financial runway into the second half of 2027, a projection that does not include potential product revenue or proceeds from a priority review voucher.
Context and implications
The combined clinical readout and analyst coverage appear to have contributed to the share price reaction in after-hours trading. The long-term dataset cited in the presentation underpins the clinical case for TA-ERT through both biomarker normalization and stabilization across multiple functional and structural measures in treated patients.
Observers should note that the company's stated runway and near-term financial position exclude potential revenue streams and voucher proceeds, items specifically called out in the company disclosure.