Search for content, post, videos

Affibody enters agreement with Acelyrin

Affibody has announced a partnership agreement with ACELYRIN to develop and commercialize izokibep, a bispecific molecule targeting interleukin-17A (IL-17), for multiple autoimmune diseases.

Under the terms of the agreement, Affibody will receive a USD 25 million upfront payment and is eligible to receive up to USD 280 million in additional regulatory and sales milestones, plus high single-digit to low double-digit royalties on sales.

“Affibody will receive a USD 25 million upfront payment.”

Under the terms of the transaction, ACELYRIN has obtained worldwide rights to izokibep except development and commercialization already granted to Affibody’s partner Inmagene Biopharmaceuticals Co., Ltd. (“Inmagene”) in selected Asian countries. Additionally, Affibody is retaining commercialization rights in the Nordic countries.

“As the innovators of izokibep, we’re honored to work with ACELYRIN to unlock this molecule’s potential and address promising new indications and solve unmet needs. In addition, we look forward to working with the ACELYRIN team to select additional targets and build new programs, in parallel with the development of izokibep,” says David Bejker, CEO, Affibody. “The partnership agreement with ACELYRIN has potential to bring us revenues of more than USD 300 million plus royalties, and complements our established partnership with Inmagene.”


Izokibep is an antibody mimetic, IL-17A inhibitor designed to overcome the limitations of monoclonal antibodies. Izokibep can reach high drug exposure levels through a single subcutaneous injection that monoclonal antibodies require IV administration to achieve. In addition, the molecule’s small size – about a tenth the size of a monoclonal antibody—also enables its potential to reach targeted tissues that may otherwise be inaccessible to the much larger monoclonal antibodies.

More than 300 patients have been dosed with izokibep to date, many for up to three years. These data confirm the safety profile of izokibep and support the strategy of fully evaluating IL-17A inhibition in pursuit of transformative efficacy across many disease states, states Affibody.

Photo of David Bejker: Affibody