Cosmo Pharmaceuticals (SWX: COPN) has rallied more than 50% over the past week, driven by positive results in late-stage trials for its hair loss treatment clascoterone.

More specifically, the Switzerland-listed company reported that patients saw a 539% relative increase in hair growth, which marks the strongest clinical performance shared to date.

As a result, the COPN share prices saw the biggest single-day jump since 2008, closing nearly 20% in the green last Wednesday, December 3. The momentum continued over the following two days, with the stock rising 14% on Thursday and another 3% on Friday.

At the time of writing, Monday, December 8, COPN stock is trading at exactly CHF 100 ($124.10), having gained more or less another 10% on the day.

Cosmo Pharmaceuticals rallies, eyes a $20 billion market

Cosmo ended the first half of 2025 on a positive note, with €50.749 million ($59.114 million) in cash and cash equivalents, up nearly 15% from the end of 2024.

Now, the stage is being set up for the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) approval, which should come following safety review wrap-ups in spring 2026.

If the regulators give it a thumbs up, clascoterone will become the first topical androgen receptor inhibitor to win such an approval, potentially allowing the company to grow further.

The strong trial data also give Cosmo an edge against existing hair loss treatments like finasteride and minoxidil, as clascoterone works directly at the hair follicle level to block DHT locally without systemic exposure.

Accordingly, the report notes that the drug could capture a significant share of the U.S. market, valued at up to $20 billion, and present an opportunity for global expansion.

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