In an effort to commercialize its growth hormone drug globally, California-based Versartis Inc has initiated phase 2/3 study of VRS-317 in Japan for children with growth hormone deficiency (GHD). Versartis is an endocrine-focused biopharmaceutical company that is developing a long-acting form of recombinant human growth hormone (rhGH).
Remarking about the trials Jeffrey L. Cleland, Chief Executive Officer of Versartis said that Japan represents a significant portion of the international pediatric GHD market.
Currently, daily rhGH products in Japan are approved at lower doses than doses used in other major markets, resulting in lower growth rates for Japanese GHD children.
The phase 2/3 trial will evaluate single dose PK/PD in the phase 2 stage followed by a twice monthly dosing regimen in the phase 3 stage with the potential to achieve growth rates comparable to those achieved with the approved doses of daily rhGH in the US. If approved by Japanese regulatory authorities, Versartis will have an opportunity to capture a significant market share in Japan with an effective treatment option that is also less burdensome than the current daily treatment.
Assuming comparable safety, pharmacokinetics and pharmacodynamics between US and Japanese GHD children in the phase 2 stage, the phase 3 stage will use the same dose under evaluation in the global phase 3 VELOCITY trial (3.5 mg/kg VRS-317 twice monthly).
The Japan phase 3 stage will be a single arm study of twice monthly VRS-317 for 12 months and will enroll pre-pubertal na?ve to treatment GHD children. The Company will also conduct an open label Extension Study in Japan to allow phase 2/3 patients to continue treatment with VRS-317 and allow enrollment of patients switching from current daily rhGH therapy to VRS-317.
