Just over a month after the FDA's Oncologic Drugs Advisory Committee (ODAC) voted 7 to 4, with two abstentions, that Marqibo (vincristine sulfate liposome injection) demonstrated a favorable risk-benefit profile as a third-line treatment for adults with Philadelphia chromosome-negative acute lymphoblastic leukemia, Talon Therapeutics Inc. reported the enrollment and dosing of the first patient.
The Phase III confirmatory study, known as the HALLMARQ study, will administer Marqibo in adults (60 and older) with newly diagnosed Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL). (See BioWorld Today, March 22, 2012.)
Based on prior FDA discussions, the San Mateo, Calif.-based company received a special protocol assessment (SPA) agreement for the large, randomized Phase III trial in front-line adult elderly ALL patients with sites currently open for enrollment. It is expected that about 400 patients will be enrolled globally.
The primary objective is to compare overall survival (OS) among subjects 60 and older with newly diagnosed ALL who receive Marqibo vs. standard vincristine as a component of multi-agent induction, intensification and maintenance chemotherapy.
"The ODAC affirmed evidence from clinical studies that support the use of Marqibo for a very rare patient population with a grave prognosis and no existing standard of treatment," said Steven R. Deitcher, president and CEO of Talon. "We will continue to work collaboratively with the FDA on the Marqibo review process, including on-going label negotiations."
The FDA extended its PDUFA date for Marqibo by three months, until Aug. 12. The original PDUFA date was May 13.
In addition to the HALLMARQ study in front-line adult elderly ALL, Marqibo also is being evaluated in an on-going Phase III trial in front-line adult elderly aggressive non-Hodgkin's lymphoma conducted by the German High Grade Non-Hodgkin's Lymphoma Study group, and in a Phase I trial in pediatric cancers, including ALL, being conducted by the National Cancer Institute. A Phase II trial of Marqibo in front-line adult ALL to be conducted by the M.D. Anderson Cancer Center is expected to begin enrolling in the third quarter.
Marqibo is an encapsulated version of widely used cancer drug vincristine, designed to provide prolonged circulation of the drug in the bloodstream and greater accumulation at the tumor site. It originally was developed by Burnaby, British Columbia-based Inex Pharmaceuticals Inc. and was acquired by Talon (formerly Hana Biosciences Inc.) in 2006. (See BioWorld Today, March 20, 2006.)
Talon has received orphan drug and fast-track designations for Marqibo for the treatment of adult ALL from the FDA. Marqibo has also received orphan drug designation in adult ALL from the European Medicines Evaluation Agency. (See BioWorld Today, July 19, 2011.)
Shares of Talon (OTCQB:TLON) dipped 2 cents Friday, to close at 77 cents.