Antares Pharma, Inc. (NASDAQ: ATRS) today announced subcutaneous methotrexate delivered with a new, self-administration device demonstrates bioavailability that is significantly greater than oral methotrexate in the treatment of adults with rheumatoid arthritis. The clinical study results were presented at the 2013 European League Against Rheumatism (EULAR) Annual Congress.
The data are from a randomized, open-label, three-way crossover study that found four hours after dose, blood concentrations of subcutaneously, self-administered methotrexate were consistently higher than concentrations of orally dosed methotrexate at all levels studied.
Oral methotrexate exposure plateaued at doses of 15 mg and higher, whereas self-administered subcutaneous methotrexate did not plateau, with exposure continuing to increase at each dose. Study investigators concluded that this resulted in higher systemic exposure than the same oral dose, which may have important clinical implications.
“These results represent a significant step forward in exploring the optimization of methotrexate, the disease modifying anti-rheumatic drug most commonly used as first-line for treatment for rheumatoid arthritis around the world,” said Michael H. Schiff, M.D., Clinical Professor of Medicine in the Rheumatology Division at the University of Colorado School Of Medicine in Denver. “Administering methotrexate subcutaneously translates to linear dose absorption which may improve the efficacy of subcutaneous methotrexate compared to oral therapy. This improved efficacy has been previously reported in the literature and observed in clinical practice. 1”The self-administration device is one component of an investigational product under review by the Food and Drug administration that combines the proprietary VIBEX™ auto-injection delivery device with an injectable version of methotrexate, the drug long regarded as the standard of care in the treatment of rheumatoid arthritis. The study of fifty adults compared the bioavailability of methotrexate administered using the investigational self-administration device-drug combination product relative to that of the bioavailability of orally dosed methotrexate. It also assessed the safety of the first-in-class delivery system.