The shares of Moderna registered a drop of nearly 24% on Wall Street after a user of the social network X disclosed a supposed report indicating that the melanoma vaccine developed alongside Merck --known in Spain and Latin America as MSD-- had not met the set expectations.
Following these leaks, the biotechnology company's stocks fell to as low as $187.6, compared to the $245.81 at which it had closed the previous session, representing a decline of 23.7% in a single day.
On X, data about the vaccine began to be shared, and the document referenced pointed to a 42% reduction in cancer recurrence or death thanks to the treatment, although the web link shared by the user did not work, according to Bloomberg.
Previously, another study, not directly comparable to the new results --which will be made public this Saturday-- had shown that the drug reduced the risk of recurrence --delay in the return of cancer-- or death by 49%, and reduced the probability of metastasis or death by 59%.
In August, both companies had experienced strong stock market gains after announcing encouraging preliminary results from the clinical trial of the vaccine, which indicated a lower recurrence of the disease and a delay in the appearance of metastasis. During that period, Moderna's value increased by up to 150%.
The pharmaceutical companies have combined an RNA therapy with Keytruda, the drug already marketed by Merck, to create this new therapeutic strategy, whose trials represent the first positive phase 3 result for both a personalized neoantigen therapy and an mRNA-based oncology treatment.