Antares Pharma, Inc. announced that the first patient has been dosed in a clinical study evaluating the Vibex MTX product which is being developed for the treatment of rheumatoid arthritis. The clinical study will evaluate several dose strengths of Vibex MTX delivered with a proprietary auto-injector versus conventional needle and syringe administration by a healthcare professional.
Vibex MTX is Antares’ proprietary, wholly owned methotrexate injection system designed for rapid self-administration in three simple steps by patients. Vibex MTX is engineered to enable patients to self-inject reliably, comfortably, and conveniently at home. It is designed to enhance safe use with an integrated, shielded needle and lockout system which prevents accidental needle sticks after use. Antares has conducted in vivo pre-clinical studies which demonstrated reproducible pharmacokinetics and good injection site tolerance when methotrexate was delivered using the Vibex technology. Vibex MTX is protected by several issued and pending patents. Uman Pharma (Montreal, Canada) will supply methotrexate for the US market and will also market the product in Canada.
Paul K. Wotton, president and CEO commented, “According to published studies, methotrexate is the most commonly used Disease Modifying Anti-Rheumatic Drug (DMARD) but a significant number of patients are unable to tolerate it when given orally. Independent market research commissioned by Antares with 200 rheumatologists has confirmed that physicians, if offered a reliable and patient-friendly method for self-injection, would like to switch many patients to an injectable form of methotrexate, potentially providing reproducible absorption, reduced side effects and a better therapeutic response. Since rheumatoid arthritis patients are often already prescribed methotrexate in combination with injectable biological products, Vibex MTX may represent a significant revenue opportunity for Antares, potentially as early as in 2013, as we continue to focus on our product based strategy.”
Rheumatoid Arthritis (RA) is a chronic autoimmune disorder characterized by painful inflammation of the synovial tissues lining the joints. RA generally starts between the ages of 25 and 55 years. Left untreated it often progresses to proliferation of tissues surrounding the joints and destruction of bones and cartilage, which restricts normal movement of the joint. According to the National Institutes of Health (NIH), RA affects about 1% of the population worldwide, including up to 2.1 million Americans, occurring in women at twice to three times the rate as that in men.
Methotrexate is a commonly prescribed Disease Modifying Anti-Rheumatic Drug (DMARD), used in an estimated 70% of rheumatoid arthritis patients either on its own or in combination with biological therapies. Methotrexate is started at a low dose, generally 7.5mg given orally, once-a-week, and titrated up for greater therapeutic effect, or until the patient incurs side effects.
The maximum oral dose given is generally 20mg to 25mg per week. Published studies have reported as many as 30% to 60% of patients experience gastrointestinal side effects with oral methotrexate, preventing further dose escalation or requiring discontinuation in some patients. Also, the extent of oral absorption of methotrexate varies considerably between patients and has been shown to decline with increasing doses, which may also contribute to insufficient therapeutic response even after dose escalation.
Switching patients from oral to parenteral methotrexate improves absorption and has been associated with improved therapeutic response. Additionally, some studies have shown a lower incidence of gastrointestinal side effects in patients that were switched from oral to parenteral methotrexate.
Antares Pharma focuses on self-injection pharmaceutical products and topical gel-based medicines. Its subcutaneous and intramuscular injection technology platforms include Vibex disposable pressure-assisted auto injectors, Valeo/Vision reusable needle-free injectors, and disposable multi-use pen injectors.