ACRS - Aclaris stock falls ~35% as zunsemetinib fails mid-stage study in skin disorder

2023-03-06 08:36:42 ET

Aclaris Therapeutics ( NASDAQ: ACRS ) oral drug zunsemetinib (ATI-450) did not meet the main goal of a phase 2a trial in patients with with moderate to severe hidradenitis suppurativa (HS).

HS is a condition which causes small, painful lumps to form under the skin, usually in areas where the skin rubs together, such as the armpits and groin.

The trial showed that zunsemetinib 50mg BID did not meet its main goal of change from baseline in inflammatory nodule, abscess (pus) count (AN) compared to placebo at week 12.

The trial also did not meet the secondary efficacy goals, including percentage of patients achieving HiSCR-50.

HiSCR-50 is generally defined as at least a 50% reduction in total AN count.

Aclaris said the placebo effect seen across all efficacy objectives was higher than what has been seen in other published HS studies reported to date.

"Despite not producing the efficacy results we had hoped for in this particularly challenging disease, we are encouraged by the consistent demonstration of zunsemetinib’s mechanism of action and the strengthening of our safety data base and continue to look forward to our next data read out of our Phase 2b study of zunsemetinib in patients with moderate to severe rheumatoid arthritis," said Aclaris' CEO Doug Manion.

The most common treatment-emergent adverse events (TEAEs) for patients on zunsemetinib were dizziness (16.7%), diarrhea (12.5%), headache (12.5%), creatine phosphokinase (CPK) elevation (10.4%) and acne (10.4%), with a majority deemed mild to moderate in severity, according to the company.

High level of CPK level may suggest potential injury or stress to muscle tissue, heart or brain.

In the trial, 37 patients discontinued treatment, 22 on zunsemetinib and 15 on placebo. Among these, 15 patients left treatment due to AEs, 11 were on zunsemetinib while 4 were on placebo.

Aclaris added that zunsemetinib was generally well tolerated.

The trial enrolled 95 patients, 48 received zunsemetinib, while 47 were on placebo, across 19 sites in the US.

ACRS -37.40% to $8 premarket March 6

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