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MDT-637 product summary

About RSV Disease

RSV is a major human respiratory tract pathogen with no currently approved U.S. treatment options among the infant, pediatric and adult populations that are susceptible to the virus. The February 2009 edition of the New England Journal of Medicine indicated that “RSV is associated with substantial morbidity in US children in both the inpatient and outpatient settings and…its control is a worldwide priority.” RSV causes pneumonia and bronchiolitis and affects individuals of all ages. The virus is highly contagious and over 90% of children worldwide are infected during the first two years of life, and RSV infection in infants has been linked to the development of childhood asthma. RSV causes considerable morbidity and mortality in several high-risk groups including premature infants, the immune-compromised, individuals with COPD and asthma, and the elderly. Globally, the annual death rate from RSV is estimated at 160,000 and the clinical burden of RSV infection is comparable to that of influenza.

The Market

The market opportunity for treatments that address RSV disease is significant and growing, with the worldwide market size for the adult ‘at risk’ population and infants estimated to be approximately $4 billion. One segment of the RSV disease market has already been established by MedImmune’s monoclonal antibody, Synagis®, which, while approved only for prophylactic use in a limited infant patient population, has achieved annual worldwide sales in excess of $1B. Of significance to its market potential, MDT-637 has demonstrated both therapeutic and prophylactic utility in clinical studies.

About MDT-637

MDT-637 is an inhalable small molecule anti-viral fusion inhibitor acquired from ViroPharma in November, 2009. MDT-637 acts by targeting and blocking the viral fusion protein, which is the only efficacious target for RSV treatments. Its role in the mechanism of RSV infection is illustrated below:

RSV Graphic

Besides being highly potent (40,000 times more potent than ribaviran) MDT-637 also showed that it was effective in reducing RSV viral count both pre- and post-infection. So, unlike Synagis® which is only indicated for preventative therapy, MDT-637 has the potential to both prevent and treat RSV infection in humans, thereby increasing the market potential.

Another advantage of MDT-637 is its potential for delivery directly to the lungs – the site of virus infection. Direct delivery to the lungs (bypassing the liver), coupled with MDT-637’s low systemic absorption, may reduce the risk for systemic toxicity.

Development Status

MDT-637 has completed preclinical studies in which it was shown to effectively block RSV infection in vitro and in the cotton rat, which is the accepted animal model of RSV infection.  In addition, MicroDose has completed two double-blind, randomized, placebo-controlled dose-ranging studies in healthy volunteers assessing the pharmacokinetics, safety and tolerability of MDT-637 after single (Study MDT-637-CP-101) and multiple ascending doses (Study MDT-637-CP-102) of inhaled MDT-637 from MicroDose’s novel dry powder nebulizer technology.

MDT-637 was well tolerated with no significant clinical adverse events and no clinically significant changes in lung function at all dose levels tested.  Cohorts of volunteers received MDT-637 up to a maximum dose level daily for 10 days, with no treatment-related trends in clinical laboratory results, vital signs, ECG results, or physical examination findings.
From a pharmacokinetic perspective, MDT-637 achieved levels in the respiratory tract that were several orders of magnitude higher than concentrations necessary to inhibit clinical isolates of RSV in vitro, whereas plasma levels of MDT-637 were markedly low.  Therefore, this new study data shows successful delivery of antiviral directly to a site of RSV infection, without reaching unnecessarily high systemic concentrations.

The MicroDose DPI’s unique capabilities will allow for the efficient delivery of MDT-637 in an easy to use product that can address all populations affected by RSV disease, from infants to the elderly.

Press Releases

MicroDose Therapeutx Announces Conclusion of MDT-637 Phase I Single and Multiple Ascending Dose Studies in Healthy Volunteers for Treatment of Respiratory Syncytial Virus (RSV)

MicroDose Therapeutx Begins Phase 1 Trial Of MDT-637 For Treatment of Respiratory Syncytial Virus

Gilead and MicroDose Therapeutx Announce License And Collaboration Agreement To Develop MDT-637 For Treatment Of Respiratory Syncytial Virus

MicroDose Therapeutx Acquires ViroPharma Portfolio of Investigational Compounds for Treatment of Respiratory Syncytial Virus (RSV)