Versartis Growth Hormone Drug Fails Phase III Test
Bay Area Versartis’ Stock Collapses as Growth Hormone Drug Flunks Phase III Test
September 22, 2017
By Alex Keown, BioSpace.com Breaking News Staff
MENLO PARK, Calif. – Shares of Versartis Inc. (VSAR) are down more than 86 percent this morning after the company said its experimental human growth hormone somavaratan failed to meet endpoints in a critical Phase III trial.
In the Velocity trial, somavaratan did not meet the primary endpoint of non-inferiority against Pfizer (PFE)’s once-daily Genotropin. Somavaratan was being developed for pediatric growth hormone deficiency (GHD).
Versartis said somavaratan did not demonstrate non-inferiority in the intent to treat population for the primary efficacy variable, height velocity (HV) at 12 months. The 12-month HV for ITT patients receiving somavaratan twice monthly was 9.44 cm, versus 10.70 cm for those receiving the daily dose of Genotropin, the company said.
Jay Shepherd, president and chief executive officer of Versartis said the company was “surprised and disappointed” to see the trial failure. He said somavaratan showed the height velocity in the range the company was looking at, but it was unable to measure up against the Pfizer drug.
Versartis shares fell from Thursday’s close of $21.65 to a low of $3 per share this morning.
Shepherd said the company has performed an initial analysis of top-line data and will continue to review the trial results in order to “gain greater insight into the trial outcome.” Shepherd added that the company intends to provide a corporate update later this year. There was no indication of layoffs or a strategic reorganization in the most recent statement issued by Versartis, but those could be coming following the Phase III failure, which was seen as crucial for the company.
Although the drug failed to demonstrate non-inferiority in intent-to-treat patients, the company said that non-inferiority was demonstrated in the per protocol population. The 12-month HV for PP patients receiving somavaratan twice monthly was 9.71 cm, versus 10.63 cm for those receiving Genotropin daily.
Somavaratan was well tolerated with treatment discontinuation rate lower than for the Genotropin arm. No new emergent safety signals were observed.
Earlier this month, Versartis presented data regarding somavaratan at the 10th International Meeting of Pediatric Endocrinology. In April at the Endocrine Society’s 99th Annual Meeting & Expo, the company shared three year analysis of somavaratan data that showed it was expected to perform “in line with daily rhGH data on key parameters, including height velocity, bone maturation and other key measures of catch-up growth, as well as IGF-I response, metabolic parameters, and safety.”
Last year, the company struck a $165 million deal with Japan-based Teijin Limited to commercialize somavaratan in Japan. The Bay Area company received $40 million in upfront money and could have received an additional $125 million in regulatory and milestones.