AnaptysBio’s anti-IL-36R drug failed a phase 2 study in palmoplantar pustulosis, a rare, inflammatory disorder that causes blisterlike sores to form on the palms of the hands and soles of the feet. The company is halting development of the drug in that indication but is pressing ahead in five others.
The phase 2 study tested the drug, imsidolimab, against placebo in 59 patients with palmoplantar pustulosis. The drug failed to beat placebo at improving patients’ scores on a measure of disease area and severity, AnaptysBio said in a statement. The Palmoplantar Pustular Psoriasis Area Severity Index (PPPASI) takes into account redness, hardening and peeling of the skin. After 16 weeks of treatment, patients taking imsidolimab logged a 6.1-point improvement on their PPPASI scores, while patients on placebo saw a 6.3-point improvement.
Patients in both groups experienced side effects at a similar rate, and no patients taking imsidolimab suffered severe or serious side effects, the company said in the statement. In the placebo group, investigators saw one severe and one serious side effect. The most common effects in both groups were mild cases of nasopharyngitis—a cold—which affected three imsidolimab patients and four placebo patients.
“While the top-line results are disappointing, I would like to sincerely thank everyone involved in the POPLAR trial, including the patients, the investigators, their staff and our employees,” said Hamza Suria, president and CEO of AnaptysBio, in the statement. “Imsidolimab is currently being advanced in 5 other immuno-dermatology indications and we look forward to multiple additional clinical readouts during 2021 and 2022.”
Those other indications include a severe form of psoriasis called generalized pustular psoriasis; acne; hidradenitis suppurativa, in which swollen, painful lumps form under the skin; ichthyosis, a group of rare, genetic skin diseases featuring dry, thickened, scaly skin; and rash and other skin-related side effects caused by EGFR-targeting cancer medicines.
AnaptysBio plans to start a phase 3 trial of imsidolimab in generalized pustular psoriasis in the middle of this year.
Besides imsidolimab, AnaptysBio is working on an anti-PD-1 drug for alopecia areata and vitiligo and an anti-BTLA med for inflammatory diseases. It also has a stable of partnered programs; the company is developing cancer drugs with GlaxoSmithKline and treatments for psoriasis and inflammation with Bristol Myers Squibb.