Dilution be damned: Scholar Rock raises $205M as 24-month data point to durability of SMA efficacy

Stuck in a hard place, Scholar Rock has raised $205 million while its stock is at an all-time low to secure the cash it needs to survive through to the delivery of phase 3 spinal muscular atrophy (SMA) data. The biotech disclosed the financing alongside 24-month data from its phase 2 trial of apitegromab in SMA.

Cambridge, Massachusetts-based Scholar Rock has come under pressure as its stock has tumbled from the $40 price it hit in September to around $5 today, forcing the biotech to cut costs to support the development of its inhibitor of the activation of latent myostatin. The situation reached a head on Friday when the biotech raised $205 million from a position of weakness and reported 24-month data from its midphase trial.

Scholar Rock reported six-month data from the phase 2 clinical study in October 2020, revealing motor function improvements that sparked a surge in its share price. The new analysis covers the 24-month data on subjects in the second and third cohorts, which enrolled non-ambulatory patients and treated them with either 2 or 20 mg/kg of apitegromab. Participants on 2 mg/kg switched to the high dose after the first year of the study.

After 12 months, subjects in the two cohorts experienced a 3.6-point mean change on the Hammersmith Functional Motor Scale Expanded, an assessment of gross motor function in SMA patients. The change rose slightly to 4.0 points by month 24. Excluding a patient with scoliosis surgery from the 24-month data brought the mean change up to 4.4 points.

Scholar Rock saw a similar trend on the measure of upper limb function, with a 1.3-point change by month 12 and a 1.9-point change by month 24. Again, removing the scoliosis surgery patient from the 24-month analysis increased the change, bringing it up to a 2.3-point shift from baseline. 

A phase 3 clinical trial is underway in non-ambulatory patients, reflecting Scholar Rock’s belief that there remains an unmet need in the population despite recent advances in the treatment of SMA. As Scholar Rock sees it, patients treated with Biogen’s Spinraza continue to experience major functional deficits and the initial gains plateau. The biotech thinks Roche’s Evrysdi suffers from some of the same limitations. 

Alongside the 24-month data, Scholar Rock disclosed its $205 million stock offering. The financing is intended to support the phase 3 SMA clinical trial through to completion. The biotech previously made cuts designed to extend its cash runway out to the fourth quarter of next year. ClinicalTrial.gov lists the primary completion date as June 2024.