Genexine and Handok said Friday that GX-H9 (HL2356), a long-acting growth hormone for pediatric use under co-development by the two, has been designated as an orphan drug in the developmental stage by the Ministry of Food and Drug Safety (MFDS).

According to the companies, the designation of GX-H9 as a development-stage orphan drug has given further momentum to its development and enhanced its possibility of being developed as an orphan drug.

They explained that orphan drug designation allows for an accelerated review, which can shorten the approval process and exempt cross-linking materials. It also allows for conditional approval after completion of phase II clinical trials, extended marketing authorization, market exclusivity, and other privileges.

Last October, the MFDS designated GX-H9 as a target for the GIFT Council before its orphan drug designation. GIFT stands for Global Innovative Products on Fast Track, a program that shortens the review period by providing early support.

GIFT supports rapid commercialization, including frequent co-examinations that review prepared materials first and professional consulting through one-on-one support between reviewers and developers. In addition, GX-H9 was designated as an orphan drug for treating growth hormone deficiency by the U.S. Food and Drug Administration (FDA) in 2016 and the European Medicines Agency (EMA) in 2021.

GX-H9 is a long-acting growth hormone utilizing Genexine's long-acting platform technology, hyFcTM. Handok and Genexine are co-developing GX-H9 for pediatric and adult patients with the goal of once-weekly administration.

Growth hormone is widely used for diseases, such as growth retardation and developmental disorders in children, due to growth hormone deficiency, as well as hormone therapy for adult disease prevention and anti-aging. Growth hormone deficiency is a rare and intractable disease, resulting in a lack of growth hormone secretion due to pituitary gland damage, genetic defects, or tumors of the pituitary gland or hypothalamus.

GX-H9 met its primary endpoint in a pediatric phase 3 clinical trial in China last year, showing significant results. Based on these results, I-Mab Biopharma, which holds the Chinese rights, plans to file for new drug authorization in China this year.