Maxygen, Inc. today announced that it has initiated a phase IIa trial to evaluate the efficacy, safety and tolerability of MAXY-G34 in the treatment of chemotherapy-induced neutropenia. MAXY-G34 is a novel pegylated granulocyte colony stimulating factor (PEG-GCSF) shown in preclinical and Phase I studies to have novel and potentially superior properties compared to the current PEG- GCSF therapy.
"Patients and physicians have limited options for treatment of neutropenia," said Russell Howard, chief executive officer of Maxygen. "With MAXY-G34, we hope to expand those options and improve the outcome for many chemotherapy patients. During this first Phase II trial we will begin to learn more about how our drug might play a role in the large, undifferentiated GCSF market."
The Phase IIa trial, which will be conducted at multiple centers in Eastern Europe, is the first trial of MAXY-G34 in patients. Approximately 30 patients with Stage I-III breast cancer will undergo TAC (docetaxel, adriamycin and cyclophosphamide) chemotherapy followed by next-day administration of either MAXY-G34 or Neulasta (control population). The trial is designed as a multiple ascending dose study, with planned doses at 10, 30, 60, or 100 micrograms per kilogram of MAXY-G34 compared to 6mg of Neulasta. Both MAXY-G34 and Neulasta will be administered as a single subcutaneous injection once per chemotherapy cycle.
The primary objective of the Phase IIa trial is to identify one or more doses of MAXY-G34 that effectively treat chemotherapy-induced neutropenia. Patient tolerability, safety, and immunogenicity will be monitored and assessed. Data will also be collected on the pharmacokinetic properties of MAXY-G34 and the mobilization of CD34+ stem cells.
Phase I Results
A Phase I trial was previously conducted to assess the safety and tolerability of MAXY-G34 in 40 healthy volunteers. This study showed MAXY-G34 to be a potent, long-lasting stimulator of neutrophils and an efficient mobilizer of CD34+ stem cells. The drug exhibited a median half-life approximately 2.3 times that of Neulasta. No serious adverse events were reported, and there were no dose-limiting toxicities. No binding or neutralizing antibodies were found at any dose level, with dose levels ranging from 10 - 150 micrograms per kilogram.