Why Alnylam Pharmaceuticals, Inc. Skyrocketed and Ionis Pharmaceuticals Inc Sank Today

Alnylam Pharmaceuticals (NASDAQ: ALNY) is up more than 40% at 11:53 a.m. EDT after the company released positive phase 3 trial data for the Apollo trial testing its RNAi drug patisiran in patients with hereditary ATTR amyloidosis with polyneuropathy. Ionis Pharmaceuticals (NASDAQ: IONS) is down 9.6% because it has a competing drug, inotersen, for the same rare genetic disease.

Ironically, when Ionis released its phase 3 data in May, the same thing happened -- Alnylam went up and Ionis went down -- because Ionis' drug had some side effects and investors were anticipating Alnylam's success.

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Source: Fool.com