Genexine's weekly growth hormone equal to Novo shot in phase 3, teeing up filing in China

Genexine’s once-weekly growth hormone has matched daily injections in a pivotal trial in China, teeing it and its partners I-Mab and Jumpcan up to file for approval next year and prepare to launch the medicine. 

The phase 3 clinical trial compared eftansomatropin alfa, Genexine’s long-acting growth hormone, to Novo Nordisk’s daily injectable Norditropin in children with growth hormone deficiency. After 52 weeks, the mean annualized height velocity in the eftansomatropin alfa arm was 10.76 cm a year, compared to 10.28 cm a year in the control cohort. The result caused the trial to meet its primary endpoint.

“We are pleased with the results from this registration trial as this demonstrates clear safety and efficacy in this potential best-in-class drug to treat children with growth hormone deficiency,” Genexine CEO Neil Warma said in a statement. “This is a significant milestone for Genexine as we demonstrate our ability to bring our novel products to market and the value of our proprietary long-acting hyFc platform.”

Genexine granted Tasgen Biotech, a company subsequently bought by I-Mab, the rights to develop, manufacture and commercialize eftansomatropin alfa in China in 2015 as part of a multi-asset deal worth $13 million upfront plus up to $40 million in milestones tied specifically to the growth hormone. I-Mab partnered with Jumpcan to commercialize the drug in China in 2021.

The collaborators plan to file for approval in China next year. If approved, eftansomatropin alfa will enter a market that already features a once-weekly option. GenSci won approval for its once-weekly Jintrolong in China after showing the treatment is noninferior to daily injections. 

Jintrolong and eftansomatropin alfa are part of a wave of once-weekly growth hormone drugs including Ascendis Pharma’s Skytrofa and Pfizer’s Ngenla. The developers have achieved once-weekly dosing using a variety of approaches. Jintrolong is a pegylated growth hormone, whereas eftansomatropin alfa uses hyFc, a component made of a portion of human immunoglobulin D and G4.