MoonLake Immunotherapeutics Stock Collapses. Why It’s Down 88%.

The biotechnology company MoonLake Immunotherapeutics pinned disappointing results in a trial of a drug meant to treat a skin condition on a “higher-than-expected placebo response rate.” (Dreamstime)

Key Points

• MoonLake Immunotherapeutics shares fell 88% to $7.52 in premarket trading after disappointing trial results for sonelokimab.
• Sonelokimab, an antibody-based therapy, didn’t show a statistically significant effect in one of two hidradenitis suppurativa trials.
• The company attributed the trial outcome to a higher-than-expected placebo response rate in the study.

Shares of MoonLake Immunotherapeutics plummeted after the biotechnology company reported disappointing trial results for an antibody-based therapy on Sunday.

In one of two identical trials, MoonLake’s sonelokimab drug didn’t have a statistically significant effect in treating the skin condition hidradenitis suppurativa, or HS, the company said. The company pinned the result on a “higher-than-expected placebo response rate.”

MoonLake shares were down 88% to $7.52 in premarket trading Monday, erasing around $3.5 billion in value.

Write to Nate Wolf at nate.wolf@barrons.com