AT 877

Fasudil is an old drug getting a new life in neurology. Approved in Japan since 1995 for preventing cerebral vasospasm after subarachnoid hemorrhage (bleeding around the brain), the small-molecule ROCK inhibitor has been sold there for three decades as an intravenous product. Woolsey Pharmaceuticals is now developing an oral reformulation, branded Bravyl and internally coded WP-0512, in a Phase 2a trial (REAL, NCT05218668) for amyotrophic lateral sclerosis, and parallel Phase 2 programs at academic sponsors are running fasudil in Parkinson's disease and early Alzheimer's [1][2][3]. Woolsey holds orphan drug designation for Bravyl in ALS from both the FDA and the EMA, which would grant seven years of US market exclusivity on approval regardless of the expired composition-of-matter patent [9]. The commercial thesis is straightforward but not easy: take a Japanese generic with decades of injectable safety data, prove the oral form modifies neurodegeneration in a Western Phase 3 trial, secure US and European approval, and price it as a specialty neurology asset. Every step of that path has broken larger companies before. What makes fasudil interesting is that its mechanism, relaxing the cellular scaffolding that controls axon growth and blood vessel tone, hits a pathway with real genetic and preclinical support in motor neuron disease, even though no ROCK inhibitor has ever cleared Phase 3 in any CNS indication.

Not a novel compound. Fasudil hydrochloride was approved by Japan's PMDA in 1995 for cerebral vasospasm after subarachnoid hemorrhage (bleeding into the space around the brain) and has been sold there as intravenous Eril [4]. It has never been approved by the FDA or EMA. Woolsey Pharmaceuticals is developing an oral reformulation (WP-0512 / Bravyl) for ALS; this is a different route and product from the approved Japanese IV drug. The Phase 2a REAL trial (NCT05218668) is an open-label study of oral fasudil at 180 mg/day, expanded in 2024 to a high-dose 300 mg/day cohort after favorable initial biomarker results; total enrollment across cohorts is approximately 40 patients [1][11]. Recruitment for the high-dose cohort completed in 2025 and Woolsey reported a 15% reduction in serum neurofilament light chain (NfL) after six months in the initial cohort, though NfL was a secondary/biomarker endpoint rather than the primary [11]. The primary endpoint is safety and tolerability, which sets the informational bar for the readout modestly. Woolsey holds FDA and EMA orphan drug designations for Bravyl in ALS [9]. No breakthrough therapy, fast track, or RMAT designation has been publicly disclosed. Woolsey closed a Series B extension in February 2025 to fund continued ALS work, but has not disclosed the amount raised or a Phase 3 budget [10]. In parallel, the Technical University of Munich runs a Phase 2 in Parkinson's disease (NCT05931575, n=75, Active, Not Recruiting) and Helse Stavanger in Norway is enrolling up to 200 early Alzheimer's patients in the FEAD trial (NCT06362707), a 12-month randomized placebo-controlled study with working memory as the primary endpoint [2][3]. Two small Chinese Phase 2 studies are testing fasudil combined with PD-1 inhibitors in metastatic castration-resistant and neoadjuvant prostate cancer (NCT07250542, NCT06861192) [5][6]. A US registrational path would almost certainly require a placebo-controlled Phase 3 with a functional endpoint. There is no publicly announced Western commercialization partner.

Rho-associated protein kinase (ROCK) is an enzyme that helps cells build and dismantle their internal scaffolding, the actin cytoskeleton. Think of it as the crew boss for how a cell holds its shape, extends processes like neurites, and contracts blood vessels. Blocking ROCK relaxes smooth muscle in blood vessels (which is why fasudil works in Japan for cerebral vasospasm) and, in neurons, allows damaged axons to regrow rather than retract. In ALS, motor neurons progressively die and lose the axonal projections that reach out to muscles. Preclinical work by Tönges and colleagues in SOD1(G93A) mutant mice showed oral fasudil prolonged survival, improved motor function, and modulated microglia activation, the brain's resident immune cell response to injury (Tönges L et al., Glia 2014;62(2):217-32, PMID 24311453) [7]. A follow-up study demonstrated survival and motor benefits even when dosing started symptomatically, which is the more clinically relevant scenario [12]. The mechanism is biologically plausible but far from human-validated for neurodegeneration. Preclinical protection in SOD1 mice has been a poor predictor of human ALS efficacy; dozens of programs have moved from strong mouse data to failed clinical trials over the past two decades. Two ROCK inhibitors have made it to Western markets in other indications: netarsudil (Rhopressa) for glaucoma and belumosudil (Rezurock) for chronic graft-versus-host disease. Both confirm the target is druggable in humans, but neither speaks to central nervous system efficacy. The Alzheimer's and Parkinson's cases rest on the same cytoskeletal-preservation logic (protecting axons and synapses from RhoA-mediated collapse) and are, if anything, thinner than the ALS rationale. Open Targets scores neurodegenerative disease at 0.55 for ROCK1, respectable but not top-tier.

The REAL trial (NCT05218668) is a Phase 2a open-label study of oral fasudil (WP-0512 / Bravyl) in ALS patients run by Woolsey Pharmaceuticals [1]. The primary endpoint is incidence of adverse events and serious adverse events, so this is fundamentally a safety trial, not an efficacy trial. Secondary endpoints include ALSFRS-R (the standard ALS functional rating scale), imaging biomarkers (brain volume, white matter tract integrity), and fluid biomarkers including serum NfL, an axonal damage marker [11]. The trial began with a 180 mg/day cohort of roughly 30 patients and was expanded in 2024 to add a 300 mg/day high-dose cohort after favorable initial signals, bringing the total to approximately 40. With no placebo comparator, statistical power to detect a real slope change in disease progression is minimal, even with the biomarker outcomes. For a disease with a 2 to 3 year median survival from symptom onset (roughly 2 to 4 years from diagnosis, depending on diagnostic delay) and highly heterogeneous progression rates, a ~40-patient open-label study is a signal-generating exercise at best. Contrast this with the current standard for ALS registrational trials, which typically requires 300 or more patients, a placebo arm, and 12 to 18 months of follow-up to detect a clinically meaningful change in ALSFRS-R slope. Woolsey has not disclosed a Phase 3 protocol or a commercial partner. The academic Parkinson's study (NCT05931575, n=75) shares the same safety-primary structure and will not answer the efficacy question either. The FEAD Alzheimer's trial (NCT06362707) is the most rigorously designed of the current fasudil neurology programs: up to 200 patients, 12-month randomized double-blind placebo-controlled, primary endpoint on working memory, run by a Norwegian academic sponsor with regulatory experience. FEAD, not REAL, is the study most likely to produce a signal that changes the commercial calculus for ROCK inhibition in CNS disease.

Our model estimates a 12% chance this drug is eventually approved. It starts from the historical base rate for Phase 2 drugs in this area (about 24%), then adjusts using ten facts about the trial and sponsor. What moves the number most: it is helped by a non-randomized design and its light or open-label blinding; it is held back by the sponsor's thin or weak approval record and weak or limited earlier-phase results. The other facts land near average for this stage, so they leave the estimate roughly where the base rate put it.

Efficacy risk dominates. ALS trials fail because the disease is heterogeneous, endpoints are noisy, and mechanism-based rationale from SOD1 mouse models has almost never translated to human benefit. A Phase 2a with roughly 40 patients, open-label, and a safety primary endpoint cannot answer whether the drug slows disease. Even the most favorable interpretation of REAL secondary endpoints will be exploratory and hypothesis-generating, not confirmatory. Safety risk is moderate but has a specific wrinkle. Fasudil has three decades of Japanese post-marketing data at doses used for cerebral vasospasm, but that experience is with intravenous administration for roughly two weeks. WP-0512 / Bravyl is an oral reformulation dosed chronically at 180 to 300 mg/day in ambulatory ALS patients over months to years. Long-term oral safety data in this population is limited, so the frequently invoked 'three decades of safety data' does not fully transfer. Known concerns include hypotension via smooth muscle relaxation, liver enzyme elevations, and theoretical effects on wound healing and immune function with sustained ROCK inhibition. Execution risk is high. Woolsey Pharmaceuticals is a small private company that closed a Series B extension in February 2025 with undisclosed proceeds [10]; funding a placebo-controlled Phase 3 in ALS would require either a licensing deal, a strategic partnership, or a substantially larger capital raise. No such transaction has been publicly announced. The academic FEAD and Parkinson's programs are not commercial vehicles and would not carry a US approval on their own. Commercial risk, assuming approval, is more nuanced now that orphan drug designation is in hand. A composition-of-matter patent covers the molecule itself and is the strongest form of drug IP; a method-of-use patent covers only a specific use of the molecule and can more easily be worked around by generic manufacturers or challenged by payers. Fasudil's composition patent expired long ago, so under normal circumstances a Bravyl approval would be exposed to generic entry through the underlying compound. But FDA orphan drug designation grants seven years of US market exclusivity from approval regardless of patent status, which is the practical protection Woolsey is banking on [9]. Even so, Riluzole is generic and cheap, edaravone (Radicava) has faced payer pushback despite meaningful pricing, and Relyvrio (AMX0035) was pulled from the US market in April 2024 after its confirmatory Phase 3 missed [8], resetting the bar for what payers will tolerate in ALS. Any new ALS drug will face intense scrutiny on functional benefit relative to cost, and orphan exclusivity does not shield against a payer refusing to reimburse a drug that fails to demonstrate clear functional benefit.

Worth watching, not chasing. The REAL topline is a low-information event given the open-label safety-primary design and n~40; a clean tolerability profile is expected, and any efficacy signal will be exploratory. The NfL biomarker signal (15% reduction at six months in the standard-dose cohort [11]) is directionally encouraging but NfL alone has not been sufficient for regulatory approval in ALS to date. The more consequential readout for the whole ROCK-in-CNS thesis is the Norwegian FEAD trial in early Alzheimer's (NCT06362707), which is powered on working memory with up to 200 patients over 12 months of treatment [3]. FEAD topline is not expected before late 2026 to 2027 given the 12-month treatment window and current enrolling status; the trial has not published a firm primary completion date on ClinicalTrials.gov as of this writing. A positive FEAD signal would validate central ROCK inhibition as a druggable strategy for neurodegeneration and dramatically re-rate every downstream fasudil program including ALS. A negative FEAD would functionally kill the CNS repositioning thesis regardless of what REAL shows. The specific data points to watch for the ALS program: a statistically defensible slope difference in ALSFRS-R decline versus matched historical controls in the REAL secondary analyses, continued NfL suppression at the 300 mg dose, and a partnering or licensing announcement from Woolsey. Together they would suggest the program has the conviction and capital to move to Phase 3. Woolsey Pharmaceuticals is private with no ticker; there is no direct trade here. The realistic commercial exit is a licensing deal to a mid-cap neurology-focused biotech contingent on positive Phase 2 data, using the seven-year orphan exclusivity window as the commercial moat. Check back after the next NEALS (Northeast ALS Consortium, the major US ALS clinical research network) or MND Association meeting for Woolsey timelines, and monitor FEAD status updates on ClinicalTrials.gov for the primary completion date to firm up.