Versartis Inc., of Mountain View, Calif., reported long-term preclinical safety data showing that VRS-317, its once-monthly version of recombinant human growth hormone, was well tolerated when dosed in monkeys every two weeks for three months. Data also further supported once-monthly treatment in humans. GLP toxicology studies in monkeys for both acute (four weeks) and long-term (13 weeks) exposure at doses of up to 25 mg/kg showed no observed adverse events, and no lipoatrophy or anti-XTEN antibodies were detected.