Astellas, Cullgen enter protein degrader research collaboration

June 15, 2023

Astellas has entered a research and exclusive option agreement with San Diego-based startup Cullgen, with the goal to discover new protein degraders and identify clinical development candidates.

According to the agreement, the two will leverage Cullgen's uSMITE targeted protein degradation platform featuring novel E3 ligands with Astellas' drug discovery expertise. The primary focus will be on Cullgen's previously identified cell cycle protein degrader, designed to target breast cancer and other solid tumors.

During the initial stages of clinical development, Cullgen will have the opportunity to share equally in the costs and profits, and will also be able to co-promote partnered products in the U.S. for the lead program. Astellas will then have an exclusive option to obtain the rights for clinical development and commercialization of the protein degrader compounds discovered. 

Cullgen will receive an initial upfront payment of $35 million from Astellas and upon its decision to exercise the license option for the lead program, Cullgen could be entitled to an additional payment of $85 million. If Astellas exercises all of its license options and successfully reaches all milestones across all programs, the deal could exceed $1.9 billion.

In addition to its collaboration with Cullgen, Astellas has also recently made significant strides in gene therapy, and entering into an agreement to license and advance a novel gene therapy developed by Kate Therapeutics. This therapy specifically targets a debilitating muscle disorder, which coincidentally is the same indication where Astellas had previously faced challenges in its attempts.