Medivir AB is an emerging research-based specialty pharmaceutical company focused on infectious diseases announced that its investigational protease inhibitor TMC435 has received “Fast Track” designation by the US Food and Drug Administration (“FDA”) for the treatment of chronic hepatitis C (CHC) genotype-1 infection. This is based on TMC435’s potential to address unmet medical needs in the treatment of CHC infection compared to currently approved therapies.

TMC435 may offer: high Sustained Virological Response (SVR) rates in genotype-1 HCV-infected patients, including hard-to-treat subgroups, short treatment duration favourable overall safety and tolerability profile, a convenient once-daily (q.d.) dosing regimen.

Furthermore, Medivir also confirms the intention to start a proof-of-concept oral, interferon-free phase 2 trial, investigating the combination of TMC435, a once daily NS3/4A protease inhibitor (PI) for the treatment of genotype-1 chronic Hepatitis C Virus (HCV) infection and Pharmasset's PSI-7977, a once daily nucleotide NS5B polymerase inhibitor. The phase 2 study, which is being managed by Tibotec Pharmaceuticals, will investigate the efficacy and safety of 12 weeks or 24 weeks of TMC435 150 mg q.d. in combination with PSI-7977 400 mg q.d. with or without ribavirin in prior null responders to peginterferon/ribavirin therapy. The primary endpoint of the trial will be sustained virological response at 12 weeks (SVR12).

Bertil Samuelsson, CSO, of Medivir commented, “We are delighted to have received the Fast Track designation for TMC435 from the FDA. This shows that TMC435 with its high safety profile, efficacy, short treatment duration and convenience of once daily dosing is believed to have the potential to provide benefit over current treatments. We believe TMC435 has the potential to become a cornerstone of future direct-acting antiviral combinations for HCV therapy. We are thus very pleased over the clinical collaboration agreement Pharmasset announced today with Tibotec, and the coming start-up of a TMC435 combination trial with Pharmasset’s once daily NS5B nucleotide inhibitor PSI-7977. This is one of several ongoing TMC435 combination trials and we expect the momentum to continue with regards to the development of TMC435.”

Fast Track is a process designed to facilitate the development, and expedite the review of drugs to treat serious diseases and to fill an unmet medical need. The purpose is to get important new drugs to the patient earlier. Fast Track addresses a broad range of serious diseases. “Filling an unmet medical need” is defined as providing a therapy where none exists or providing a therapy that may potentially be superior to existing therapy.

If there are existing therapies, a fast track drug must show some advantage over available treatment, such as: showing superior effectiveness, avoiding serious side effects of an available treatment, improving the diagnosis of a serious disease where early diagnosis results  an improved outcome, decreasing a clinically significant toxicity of an accepted treatment.

A drug that receives Fast Track designation is eligible for some or all of the following: more frequent meetings with the FDA to discuss the drug’s development plan and ensure collection of appropriate data needed to support drug approval, more frequent written correspondence from the FDA about such things as the design of the proposed clinical trials, eligibility for Accelerated Approval, i.e., approval on an effect on a surrogate or substitute endpoint reasonably likely to predict clinical benefit, Rolling Review, which means that a drug company can submit completed sections of its New Drug Application (NDA) for review by FDA, rather than waiting until every section of the application is completed before the entire application can be reviewed. NDA review usually does not begin until the drug company has submitted the entire application to the FDA and dispute resolution if the drug company is not satisfied with an FDA decision not to grant Fast Track status.

In addition, most drugs that are eligible for Fast Track designation are likely to be considered appropriate to receive a Priority Review.

Once a drug receives Fast Track designation, early and frequent communication between the FDA and a drug company is encouraged throughout the entire drug development and review process. The frequency of communication assures that questions and issues are resolved quickly, often leading to earlier drug approval and access by patients.

TMC435, an investigational CHC protease inhibitor currently in phase 3 clinical development, is a highly potent, selective and safe once-daily (q.d.) drug jointly developed by Tibotec Pharmaceuticals to treat chronic hepatitis C virus infections.

TMC435 is being developed in combination with PegIFN/RBV and in combination with Direct-Acting Antiviral (DAA) agents without peginterferon and with or without ribavirin (RBV). In June 2011 the combination study of TMC435 with TMC647055, a non-nucleoside NS5B polymerase inhibitor being developed by Tibotec Pharmaceuticals, was initiated.

Three global clinical phase 3 response guided studies were initiated in early 2011 by Tibotec: TMC435-C208 or QUEST-1 includes approximately 375 treatment-naïve patients, TMC435-C216 or QUEST-2 includes approximately 375 treatment-naïve patients, TMC435-C3007 or PROMISE includes approximately 375 who have relapsed after prior interferon-based treatment.

In parallel with the recent start of the global phase III studies, TMC435 is currently in a follow up phase in three phase 2b clinical trials (TMC435-C205, TMC435-C206 and TMC435-C215) in G1 treatment-naïve and in G1 patients that failed previous IFN-based treatment. More safety and efficacy data from the phase 2b trials will be presented at scientific meetings later in 2011.

Hepatitis C is a blood-borne infectious disease of the liver and is a leading cause of chronic liver disease and liver transplants. The WHO estimates that nearly 180 million people worldwide, or approximately 3% of the world's population, are infected with hepatitis C virus (HCV). The US Centers for Disease Control (“CDC”) has reported that almost three million people in the United States are chronically infected with HCV.