Two new cancer cases have prompted Kyowa Kirin to shutter all clinical studies of its investigational anti-OX40 monoclonal antibody designed to treat inflammatory diseases.
The discontinuation will likely disrupt the Japanese company’s previously stated plan to request FDA approval of the asset in atopic dermatitis in the first half of this year.
“This matter does not constitute an immediate determination to discontinue the entire rocatinlimab development program,” a Kyowa spokesperson told Fierce. “However, at this point in time, we consider the likelihood of continuing development or resuming clinical trials to be extremely low.”
News of the shuttered studies comes about a month after Amgen abandoned a pact with Kyowa centered around the candidate, dubbed rocatinlimab.
A recent safety review of rocatinlimab found “emerging concerns of malignancies with possible viral or immune-related links,” according to a March 3 release from Kyowa.
One new confirmed case and an additional suspected case of Kaposi sarcoma—a soft tissue cancer—were reported on top of another previously recorded case. The identified cancers indicate a “potential mechanistic link to OX40 pathway modulation,” according to the company.
“Based on this update, both Kyowa Kirin and Amgen have concluded that the potential risks may outweigh the benefits for the studied patient populations,” the release reads.
The two pharmas are working to alert trial investigators and regulators, with plans to terminate all studies after patients are followed up with.
The collaborators had been testing out rocatinlimab in a vast R&D program, running eight phase 3 trials in atopic dermatitis alone. The anti-OX40 asset was also being evaluated in a late-stage study for prurigo nodularis, a chronic skin condition characterized by itchy bumps.
Additionally, rocatinlimab was being studied in moderate to severe uncontrolled asthma, with a midstage trial readout expected this year.
Back in 2021, Amgen paid $400 million to align with Kyowa on the program, offering the Japan-based pharma up to $850 million in potential milestone payments.
But, earlier this year, Amgen walked away from the partnership. At the time, Kyowa attributed the decision to Amgen’s strategic portfolio prioritization.
In its most recent release, Kyowa said the safety review was “conducted over the last several weeks,” so it is unclear whether Amgen was aware of these findings before terminating the deal at the end of January.
The California pharma’s decision may have been made on the strength of the data alone. In a late-stage study, rocatinlimab beat placebo as a treatment for atopic dermatitis, but questions remained about the asset’s positioning in a competitive space. Unfavorable comparisons to Sanofi and Regeneron’s juggernaut Dupixent prompted William Blair analysts to forecast “a moderate commercial opportunity” for rocatinlimab as a later-line therapy.
Now, the two companies aim to analyze the full rocatinlimab dataset and pledged to share more information once those assessments are done. “The overall number of malignancy cases across the program remains below expected background rates,” Kyowa noted.
Editor's note: This article was updated at 11:21 a.m. ET on March 3 to include comment from Kyowa.