Moderna shares plunged as much as 25% after partial clinical trial data leaked for its personalized cancer vaccine developed with Merck , despite the full results showing promising outcomes for melanoma patients. Analysts attribute the selloff largely to inflated investor expectations rather than disappointing clinical results. CNBC reports: The personalized vaccine, known as intismeran autogene, paired with Merck's immunotherapy Keytruda reduced the risk of recurrence or death in certain melanoma patients by 42% compared with Keytruda alone. The data also showed the shot along with Keytruda reduced the risk of cancer spreading to distant parts of the body or death by 38%, compared with just the immunotherapy.…