Viking Therapeutics, a clinical-stage biopharmaceutical company focused on the development of novel therapies for metabolic and endocrine disorders, announced positive results from a 12-week, Phase 2 clinical trial of VK5211 in patients who recently suffered a hip fracture. Top-line data showed that the trial achieved its primary endpoint, demonstrating statistically significant, dose dependent increases in lean body mass, less head, following treatment with VK5211 as compared to placebo. The study also achieved important secondary endpoints, demonstrating statistically significant increases in appendicular lean body mass and total lean body mass for all doses of VK5211, compared to placebo. VK5211 demonstrated encouraging safety and tolerability in this study, with no drug-related serious adverse events (SAEs) reported.
VK5211, Viking’s lead program for muscle and bone disorders, is an orally available, non-steroidal selective androgen receptor modulator (SARM) designed to selectively stimulate muscle and bone formation with reduced activity in peripheral tissues such as skin and prostate. The Phase 2 clinical trial was a randomized, double-blind, placebo-controlled, parallel group, international study designed to evaluate the efficacy, safety and tolerability of VK5211 in patients recovering from hip fracture surgery. A total of 108 patients were randomized to receive once-daily VK5211 doses of 0.5 mg, 1.0 mg, 2.0 mg, or placebo for 12 weeks. Top-line results include:
- All doses of VK5211 demonstrated statistically significant increases in total lean body mass, less head, the study’s primary endpoint. Placebo-adjusted increases in lean body mass were 4.8% at 0.5 mg (p < 0.005), 7.2% at 1.0 mg (p < 0.001), and 9.1% at 2.0 mg (p < 0.001). These corresponded to placebo-adjusted increases of 1.6 kg at 0.5 mg (p < 0.005), 2.5 kg at 1.0 mg (p < 0.001), and 3.1 kg at 2.0 mg (p < 0.001).
- The proportion of patients experiencing at least a 5% increase in total lean body mass, less head, were 19% with placebo, 61% at 0.5 mg, 65% at 1.0 mg, and 75% at 2.0 mg (p < 0.01 for each). The proportion of patients demonstrating at least a 2.0 kg gain in total lean body mass, less head, were 14% with placebo, 57% at 0.5 mg, 65% at 1.0 mg, and 81% at 2.0 mg (p < 0.01 for each).
- All doses of VK5211 produced statistically significant increases in appendicular lean body mass, a secondary efficacy endpoint. Placebo-adjusted increases in appendicular lean body mass were 6.1% at 0.5 mg (p < 0.01), 9.0% at 1.0 mg (p < 0.001), and 10.2% at 2.0 mg (p < 0.001). These corresponded to placebo-adjusted increases of 0.8 kg at 0.5 mg (p < 0.05), 1.3 kg at 1.0 mg (p < 0.001), and 1.4 kg at 2.0 mg (p < 0.001).
- All doses of VK5211 produced statistically significant increases in total lean body mass, including head, a secondary efficacy endpoint. Placebo-adjusted increases in lean body mass were 4.7% at 0.5 mg (p < 0.005), 6.8% at 1.0 mg (p < 0.001), and 8.3% at 2.0 mg (p < 0.001). These corresponded to placebo-adjusted increases of 1.7 kg at 0.5 mg (p < 0.005), 2.6 kg at 1.0 mg (p < 0.001), and 3.1 kg at 2.0 mg (p < 0.001).
- Patients receiving VK5211 demonstrated numerical improvements in certain exploratory assessments of functional performance, including the 6-minute walk test and short physical performance battery, compared with placebo. These endpoints were not powered for significance. Further evaluation of exploratory functional endpoints is underway.
- There were no significant differences in the rates of adverse events reported among patients receiving VK5211 compared with placebo. There were no dose-related differences in reported adverse events among various VK5211 treatment groups. No drug-related SAEs were observed in patients receiving VK5211.
“We are pleased that this trial succeeded in both the primary efficacy endpoint, as well as important secondary endpoints, demonstrating VK5211’s potential benefit in this setting. The study achieved statistical significance at all doses with a clear dose-response and, in our view, provides compelling evidence of VK5211’s potent pharmacologic effect on muscle growth,” said Brian Lian, Ph.D., chief executive officer of Viking. “We are also encouraged by VK5211’s preliminary safety and tolerability profile, particularly by the fact that no drug-related SAEs were observed. This is important to note given the medically fragile profile of hip fracture patients, many of whom are older adults with multiple comorbidities requiring multiple concomitant therapies. We are gratified to see VK5211 produce such robust pharmacologic effects along with a promising safety profile in this challenging population.”
“The degree of improvement in lean body mass in this group of older persons who are prone to losing muscle is impressive. Having a drug like this available that can be taken easily and safely soon after hip fracture would provide a valuable adjunct to other therapeutic strategies such as physical therapy and a protein-rich diet to boost patients’ chances for resuming usual activities,” said Jay Magaziner, PhD, MSHyg, Professor and Chair, Department of Epidemiology and Public Health at the University of Maryland School of Medicine and an international authority on the consequences of hip fracture.