BridgeBio Pharma Enters Partnership with Kyowa Kirin for Skeletal Dysplasias in Japan

Rare Daily Staff

BridgeBio Pharma said it entered into a collaboration with Kyowa Kirin for the development and commercialization of its experimental therapy infigratinib for achondroplasia, hypochondroplasia, and other skeletal dysplasias in Japan.

Under the terms of the agreement, Kyowa Kirin will pay BridgeBio an upfront payment of $100 million as well as royalties up to the high-twenties percent on sales of infigratinib in Japan, with the potential for additional milestone-based payments.

Achondroplasia is the most common cause of disproportionate short stature. Achondroplasia impacts overall health and quality of life, leading to medical complications such as obstructive sleep apnea, middle ear dysfunction, kyphosis, and spinal stenosis. The condition is uniformly caused by an activating mutation in FGFR3.

Infigratinib is an oral small molecule designed to inhibit FGFR3 and thus target FGFR3-driven skeletal dysplasias at their source, including achondroplasia and hypochondroplasia.

“By partnering with Kyowa Kirin, we hope to significantly accelerate the development of infigratinib to potentially provide options for children with achondroplasia, hypochondroplasia, and eventually skeletal dysplasias in Japan,” said Justin To, CEO of QED Therapeutics, BridgeBio’s affiliate for skeletal dysplasias. “We hear the need from the community for a once-daily oral treatment option and are looking forward to initiating our trials in Japan at a later date.”

In December 2023, BridgeBio dosed the first child in PROPEL 3, a one-year, randomized, placebo-controlled phase 3 pivotal trial, evaluating the efficacy and safety of infigratinib in children with achondroplasia aged 3 to less than 18 years with open growth plates. The phase 3 builds on the success of PROPEL 2, a Phase 2 trial of infigratinib in achondroplasia which demonstrated a +3.38cm/year increase in annualized height velocity, the strongest clinical result published to date.

Kyowa Kirin hopes to initiate a Japanese registrational trial in 2025.

Photo: Justin To, CEO of QED Therapeutics