U.S. stock markets saw notable moves on Monday, with Vertex Pharmaceuticals (VRTX.US) surging nearly 7% in early trading to hit an all-time high. In contrast, competitor Sionna Therapeutics (SION.US) plunged more than 90%, reaching a record low.

This sharp divergence in stock performance came after Sionna announced that it would discontinue its experimental cystic fibrosis drug, SION-719, following a mid-stage clinical trial failure. The drug did not meet its primary endpoint, prompting the company to halt further development.

Investors had previously worried that Sionna's drug could pose a threat to Vertex Pharmaceuticals' core cystic fibrosis business. However, the trial's failure has alleviated those concerns. Vertex Pharmaceuticals markets Trikafta and Alyftrek for treating cystic fibrosis, a rare, chronic, and life-shortening genetic disease that causes progressive lung damage.