Viridian Therapeutics and Kissei Pharmaceutical have signed an exclusive partnership and licence agreement for advancing veligrotug and subcutaneous VRDN-003, potential treatments for thyroid eye disease (TED), in Japan.

Kissei will gain an exclusive licence for the development and commercialisation of these two anti-insulin-like growth factor-1 receptor (IGF-1R) antibodies.

In return, Viridian will receive $70m upfront, along with the opportunity to earn up to $315m based on development, regulatory, milestones and sales achievements, along with tiered royalties on net sales that could range from 20s to mid-30s percentages.

Kissei will take over all responsibilities related to the development, regulatory processes, commercialisation efforts and associated costs in Japan.

Viridian president and CEO Steve Mahoney stated: “After running a very competitive partnering process, we are thrilled to partner with Kissei to bring these potential best-in-class medicines to TED patients in Japan.

“Kissei has an established strong track record of successfully developing and commercialising in-licensed, rare disease medicines. Kissei shares our enthusiasm and commitment to these programmes, and we believe Kissei is an ideal partner for us in Japan. Both companies look forward to moving quickly to advance these novel treatment options for patients.”

TED is characterised by inflammation, growth and tissue damage around the eyes, leading to symptoms such as discomfort, swelling and double vision.

VRDN-003 is a half-life extended anti-IGF-1R antibody that shares a binding domain similar to veligrotug.

Renexes played a pivotal role by advising Viridian during the transaction. Kissei chairman and CEO Mutsuo Kanzawa stated: “As we seek to further expand our pipeline in rare and intractable diseases, we are very excited by the potential of veligrotug and VRDN-003 to address the significant unmet needs of TED patients in Japan, based on veligrotug’s strong and consistent Phase III clinical data in THRIVE and THRIVE-2.”