Zeltia and partner Johnson & Johnson have received some bad if not unexpected news after regulators in the USA told the firms that they require more information about the combination of the Spanish drugmaker’s Yondelis and J&J”s Doxil as a treatment for relapsed ovarian cancer.

The US Food and Drug Administration had issued a complete response letter regarding the New Drug Application for Yondelis (trabectedin) when administered in combination with J&J’s Doxil (doxorubicin). The latter’s Centocor Ortho Biotech unit said that the agency has requested additional information, “including overall survival data from the company's ongoing pivotal trial and additional clinical pharmacology studies”.

J&J says it “continues to believe that trabectedin has an important role in the treatment of patients with ovarian cancer”. It is reviewing the FDA's letter and will respond to the agency's questions as quickly as possible.

The letter comes a couple of months after the FDA’s Oncologic Drugs Advisory Committee voted 14-1 against approval of the combo, saying that the six-week benefit in progression-free survival shown in a Phase III trial does not justify the green light for the treatment. The panel expressed concern about a notable increase in severe and life-threatening adverse events in the Yondelis treatment group, including more than twice as many incidents of pulmonary embolism. Cardiac adverse events were three times higher in the trabectedin group, and liver enzyme increases were also higher.