Kyowa Kirin will stop all trials of an eczema drug once seen as a possible future blockbuster, claiming a new safety review has led the company to believe that the treatment’s risks may outweigh its benefits.
In a Tuesday statement, the company said a planned evaluation conducted by the company and former development partner Amgen in recent weeks unearthed “emerging concerns of malignancies” related to treatment with a therapy known as rocatinlimab. These concerns included one new confirmed case and another suspected case of Kaposi’s sarcoma, a cancer that forms around skin lesions.
The findings suggest a potential link between onset of the cancer and the drug’s mechanism of modulating an immunogical pathway called OX40. While the overall number of cases is below expected background rates, the “characteristics” involved “raised a plausible biological concern that cannot be excluded,” the company said.
All studies will be discontinued after study participants complete their required safety follow-up visits, Kyowa Kirin added.
Rocatinlimab is a part of a class of drugs known as anti-OX40 antibodies, which some drugmakers have looked to as a new way to treat eczema and other immune diseases. Sanofi bought into the competition when it acquired Kymab in 2021, gaining rights to a drug now known as amlitelimab. Amgen got involved the same year, paying $400 million upfront and promising up to $850 million more for most rights to rocatinlimab.
Both drugs have produced data that have caused the initial enthusiasm to wane, however.
Last year, study results published in The Lancet showed that rocatinlimab outperformed a placebo in reducing the number and size of skin lesions in a Phase 3. But rocatinlimab also didn’t look better than the top therapy on the market, Dupixent, and was associated with side effects that analysts viewed as causing commercial problems in the future.
Amgen handed back rights in February and, at the time, Kyowa Kirin said it was still confident in the program and planned to submit it to drug regulators in the U.S. and Japan. Those plans changed following the safety review.
“Although this outcome is not what we hoped for, our work has not been in vain. The knowledge gained from the program will contribute meaningfully to the broader understanding of the OX40 pathway and future research efforts,” said Abdul Mullick, president and chief operating officer of Kyowa Kirin, in a statement.
Sanofi’s drug, meanwhile, produced mixed study results in Phase 3 testing and, as with rocatinlimab, investigators recorded one case of Kaposi’s sarcoma in a study participant. Sanofi has said it intends to seek approvals nonetheless. But some analysts have dialed back sales expectations. In a note to clients last week after speaking with a dermatology expert, Jefferies analyst Michael Leuchten wrote the sarcoma case likely relegates amlitelimab to a “niche population.”
It doesn’t “totally remove the commercial opportunity for the drug, but certainly limits it to patients who are more needle-averse,” Leuchten wrote. Two other Phase 3 studies are currently ongoing.
Rocatinlimab was being tested in the indications prurigo nodularis, moderate-to-severe atopic dermatitis and moderate-to-severe asthma.
