IO Biotech claimed its investigational vaccination for metastatic melanoma reduced disease progression but failed to reach the main study goal.

In a late-stage research, IO Biotech reported on Monday that their experimental combination vaccine for a particular type of skin cancer helped reduce the disease's growth. However, the vaccination only failed to meet the main goal when the results lacked statistical significance. After rising as much as 50% before the bell, the drug developer's shares were down 22.4% in morning trading.

In 407 patients with metastatic melanoma, IO Biotech was studying the vaccine in conjunction with Merck's Keytruda. According to the business, patients who received the combo vaccination Cylembio lasted a median of 19.4 months without their condition worsening, whereas those who received Keytruda alone only lived for 11 months.

However, the company noted that the results did not meet the required statistical significance threshold of 0.045. CEO Mai-Britt Zocca described it as an extremely close outcome, saying it was missed "by a hair" during a conference call. According to the business, there were no new safety signals, and the combo vaccine was well received. Additionally, it noted a tendency for overall survival to improve.

The results and next steps for a possible regulatory submission will be discussed during IO Biotech's meeting with the US Food and Drug Administration this fall. H.C. Wainwright analyst Emily Bodnar stated that there is probably still a chance for FDA clearance because the agency might accept filings for a subgroup of patients or ask for more developed overall survival data that is due the following year.