TLC suffers as FDA requests more data

The Liposome Company has received another slight blow on news that theUS Food and Drug Administration has requested additional data from trials of its anticancer agent Evacet (liposomal doxorubicin). In October last year, the firm said it would withdraw and resubmit its New Drug Application for the drug, in order to address issues raised at an FDA advisory committee meeting the previous month (Marketletters September 27 and October 25, 1999). It had previously hoped to submit the new NDA by the end of last year.

While the FDA had given its permission for the firm to use tumor response and not survival as the primary endpoint in its pivotal studies, the panel was unhappy with this endpoint and pointed out that TLC had widely missed the mark for that outcome in one study. Evacet was developed to reduce the cardiotoxicity seen with conventional doxorubicin. However, while the reduced toxicity in trials was promising, the efficacy data were not as positive, an FDA reviewer said. A third study comparing Evacet/cyclophosphamide with epirubicin/cyclophosphamide was thrown out by the agency, which said that the two drugs were not appropriate comparators.

TLC says that it recently met with the FDA to discuss the additional analyses it had submitted at the end of 1999. However, it says that, based on these discussions, "the company now believes that additional clinical data will be needed in order to obtain marketing approval."