Antares Pharma, Inc. (NASDAQ: ATRS) today announced the approval of OTREXUP ™ (methotrexate) injection by the U.S. Food and Drug Administration (FDA). OTREXUP ™ is the first FDA approved subcutaneous (SC) methotrexate (MTX) for once weekly self-administration with an easy-to-use, single dose, disposable auto injector. OTREXUP ™ is indicated for adults with severe active rheumatoid arthritis (RA) who have had an insufficient therapeutic response to or are intolerant of an adequate trial of first line therapy including full dose non-steroidal anti-inflammatory agents (NSAIDs), or children with active polyarticular juvenile idiopathic arthritis (pJIA). The FDA also approved adult use of OTREXUP ™ for symptomatic control of severe recalcitrant, disabling psoriasis that is not adequately responsive to other forms of therapy. In 2012, approximately six million prescriptions were written across all dosage forms of MTX in the U.S. to treat patients for RA, pJIA and psoriasis, the same indications for which OTREXUP ™ has been approved. MTX treatment is usually initiated with oral tablets, however; many patients experience an inadequate response for reasons of efficacy or tolerability. “This new delivery system for methotrexate provides a welcome option for physicians and their patients to continue effective use of methotrexate. OTREXUP ™ can be used when a response is inadequate or there are tolerability issues with oral methotrexate, before adding or switching to costlier therapies,” said Dr. Michael Schiff, Clinical Professor of Medicine in the Rheumatology Division at the University Of Colorado School Of Medicine in Denver. “The availability of an easy and safe way to administer subcutaneous methotrexate may overcome some of the current barriers to parenteral administration which could enable more patients to realize the possibility of continued disease control and therefore benefit from subcutaneous methotrexate.” Human study data submitted to the FDA demonstrated increased bioavailability of SC MTX compared to oral MTX at every dose. These results confirm and strengthen the findings of previously published bioavailability data, and highlight the saturable limitations of oral MTX that result in a bioavailability plateau at 15mg. These important data are included in the approved OTREXUP ™ label and have been selected for a prestigious oral presentation this month at the American College of Rheumatology Scientific Meeting. There has been substantial literature published that documents the potential benefits of SC MTX after an inadequate response to oral MTX. In the United States, however, use of parenteral MTX is often overlooked for the treatment of RA or psoriasis, primarily due to the challenges of self-administration associated with compromised manual dexterity, needle phobia, or patients’ lack of confidence to accurately and safely self-inject with a vial, needle and syringe.