Seattle, Washington-based biopharmaceutical company Cell Therapeutics Inc. experimental drug, Pixuvri (Pixantrone), received a Food and Drug Administration complete response letter, at the same time it will have to provide an additional clinical study in order to obtain final approval.

The drug is intended for the treatment of refractory aggressive non-Hodgkin´s lymphoma in patients that do not respond to other options. The drug was developed jointly with Novartis AG, who has the option to license the product for primarily 7.5 million dollars, with payments of up to 104 million dollars.

However, Novartis said they could walk away from the project, that will start a new set of trials as September this year, and expected to end by the second trimester of 2011. Almost 18 additional months are expected to last before there could primary and secondary endpoints are met, the cost is estimated between 20 to 25 million dollars. Figure that is opposed to Cell Therapeutics last balance, that showed almost 4 million dollars in assets.

Cell Therapeutics markets another drug, Zevalin, for the treatment of patients with relapsed or refractory, low-grade or follicular B-cell non-Hodgkin's lymphoma (NHL), including patients with rituximab refractory follicular NHL. Zevalin is also indicated, for the treatment of relapsed or refractory, rituximab-naive, low-grade and follicular NHL based on studies using an endpoint of overall response rate, which is a surrogate for progression free survival.