Moderna shares plunge on apparent cancer vaccine data leak

What happened: Moderna shares fell more than 25% and Merck fell over 3% after what appeared to be an early release of Phase 3 trial results for their experimental cancer vaccine. The report appeared on Oncology Central around 12:30 p.m. ET and was taken down shortly afterward. Key numbers: Moderna fell more than 25%, Merck over 3%. Why it matters: The companies had announced in August that the trial met its main goals but had not disclosed detailed results, so the apparent early publication gave investors their first look at the treatment's effectiveness in the larger Phase 3 study. Market: -1.5% today ($147.69), +39.8% YTD, 1.2x vol — as of 18:02 UTC

Moderna shares fell more than 25% and Merck fell over 3% after what appeared to be an early release of Phase 3 trial results for their experimental cancer vaccine. The report appeared on Oncology Central around 12:30 p.m. ET and was taken down shortly afterward.

The companies had announced in August that the trial met its main goals but had not disclosed detailed results, so the apparent early publication gave investors their first look at the treatment's effectiveness in the larger Phase 3 study. Market: -1.5% today ($147.69), +39.8% YTD, 1.2x vol — as of 18:02 UTC