Scholar Rock Announces Publication of Phase 1 Clinical Trial Data Evaluating Apitegromab in Healthy Volunteers in the Journal Advances in Therapy
“The Phase 1 data provided an important foundation to support advancing the development of apitegromab and we are excited to share these detailed results through a publication in this peer-reviewed journal,” said
The objectives of the Phase 1, double-blind, placebo-controlled study were to assess the safety, immunogenicity, pharmacokinetics (PK), and pharmacodynamics (PD as measured by serum latent myostatin levels) of apitegromab to support future clinical studies. A total of 66 healthy volunteers were enrolled and randomized to receive either intravenous (IV) apitegromab or placebo at doses between 1 mg/kg and 30 mg/kg. Key findings shared in Advances in Therapy include:
- Single- and multiple-ascending doses of apitegromab were safe and well-tolerated at IV doses up to 30 mg/kg. No anti-drug antibodies were detected in subjects receiving apitegromab.
- Apitegromab demonstrated a linear, dose-proportional PK profile and a half-life of 24-31 days across the evaluated doses.
Apitegromab demonstrated dose-dependent increases in serum latent myostatin concentrations as well as durable target saturation.
- Mean serum latent myostatin levels increased and plateaued between day 14-28 following single doses of up to 10 mg/kg and between day 42-56 for 20 mg/kg and 30 mg/kg doses. This contrasts with mean serum latent myostatin levels remaining at or near baseline levels following placebo.
- For subjects who received multiple doses of apitegromab (every 2 weeks for a total of three doses), mean serum latent myostatin concentrations remained elevated through the third dose and began to decline by day 56 for the 10 mg/kg and 20 mg/kg doses and day 84 for the 30 mg/kg dose.
The data from this Phase 1 study, as well as preclinical data, supported advancing the development of apitegromab to the TOPAZ Phase 2 trial, which evaluated apitegromab’s potential to improve motor function in patients with Type 2 and Type 3 SMA.
Apitegromab is a selective inhibitor of the activation of myostatin and is an investigational product candidate for the treatment of patients with spinal muscular atrophy (SMA). Myostatin, a member of the TGFβ superfamily of growth factors, is expressed primarily by skeletal muscle cells, and the absence of its gene is associated with an increase in muscle mass and strength in multiple animal species, including humans.
Spinal muscular atrophy (SMA) is a rare, and often fatal, genetic disorder that typically manifests in young children. An estimated 30,000 to 35,000 patients are afflicted with SMA in
This press release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the potential of SRK-181, Scholar Rock’s future expectations, plans and prospects, including without limitation, Scholar Rock’s expectations regarding its growth, strategy, progress and timing of its clinical trials, the potential of its proprietary platform, and its intellectual property protection. The use of words such as “may,” “might,” “will,” “should,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “project,” “intend,” “future,” “potential,” or “continue,” and other similar expressions are intended to identify such forward-looking statements. All such forward-looking statements are based on management's current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include the possibility that data from the TOPAZ clinical trial will be inconsistent with the data observed in subsequent clinical trials, competition from third parties that are developing products for similar uses, Scholar Rock’s ability to obtain, maintain and protect its intellectual property, Scholar Rock’s dependence on third parties for development and manufacture of product candidates including to supply any clinical trials, Scholar Rock’s ability to manage expenses and to obtain additional funding when needed to support its business activities and establish and maintain strategic business alliances and new business initiatives, and the impacts of public health pandemics such as COVID-19 on business operations including its clinical trials, as well as those risks more fully discussed in the section entitled "Risk Factors" in Scholar Rock’s Annual Report on Form 10-K for the year ended