Results on MIV-310 in phase IIa study

Huddinge, SWEDEN


HUDDINGE, Sweden, May 31, 2002 (PRIMEZONE) -- A phase IIa clinical study with Medivir's compound MIV-310 shows a major antiviral effect in patients with multi drug resistant HIV.

The addition of MIV-310 (alovudine) has demonstrated a strong reduction in viral load levels in HIV patients who, due to resistance development, do not respond to treatment with present therapies. The results in this phase IIa study are particularly important in light of the increasing problem with resistance development against currently available anti-HIV therapies.

Design

This open-label proof-of-principle study included 15 HIV-infected patients. The patients received individualized stable combination treatment with 3-5 anti-HIV drugs, yet they still exhibited treatment failure. MIV-310, at a once daily dose of 7.5 mg, was added to their regimen over 4 weeks.

Results

All patients responded positively to the MIV-310 treatment and MIV-310 was generally well tolerated. There were no withdrawals from therapy and no serious adverse events occurred. The patients responded to MIV-310 treatment with an overall median reduction in viral load in plasma of 1.13 log10, that is a 92.6% reduction. Patients whose other medication did not include d4T (stavudine) responded with a median reduction of 1.88 log10, corresponding to a 98.7% reduction in viral load. Patients with concomitant d4T treatment responded significantly but with a log reduction of less than 1 suggesting an interaction between MIV-310 and d4T as previously shown between zidovudine and d4T. These results show that MIV-310 is an extremely potent nucleoside reverse transcriptase inhibitor (NRTI) with an exceptional multi drug resistance profile. Like other NRTIs, MIV-310 is expected to have a narrow therapeutic window. Importantly, no resistance development was observed when the reverse transcriptase (RT) coding regions in HIV where compared pre- and post- treatment. When treatment was stopped the virus levels returned to that seen before treatment. The results from the phase IIa study will be presented during the XI International HIV Drug resistance Workshop in Sevilla during July 2-5 and during the XIV International AIDS Conference in Barcelona July 7 -12 2002.

MIV-310 future

The results from this proof-of-principle study show that the NRTI MIV- 310 is effective and could form part of future therapies in patients with multi drug resistant HIV. Resistance against present therapies is a rapidly growing problem both among treatment experienced and naive patients. Medivir will use the know-how from this and previous clinical studies, under guidance from the regulatory authorities, to conduct further clinical development in a safe, optimal and timely way.

US Patent and Trademark Office recently issued Medivir with patent no 6,358,840 protecting MIV-310 (FLT) as an antiviral against HIV. The patent will expire in March 2019. Processing of the patent application was delayed by "interference" proceedings in which a patent court investigated who was first to invent this important new HIV antiviral. The proceedings were between two companies having some of the world's largest nucleoside libraries, Medivir and Wellcome plc (now GlaxoSmithKline plc) and the court ruled in favour of Medivir and invalidated the competing Wellcome patent. In Europe, the MIV-310 patent and SPC (supplementary protection certificate) expire in 2012.

Market

It is estimated that there are over 1.4 million cases of HIV/AIDS in the western world of these a significant number show drug resistance. A recent study found HIV drug resistance to NRTIs in 70 percent of tested patients. The total sales of NRTIs in the western world amounted to US 2.7 billion during 2001 and are predicted to reach US 6 billion in 2005.

Telephone conference

Medivir will host a teleconference on May the 31 at 11.00 SE time. Jonas Frick CEO, Johan Harmenberg VP Pharmaceutical Development and Rein Piir, CFO/IR will present and comment on the phase IIa results. To participate please dial +44 (0) 20 8781 0577, code Medivir. The teleconference will be recorded and saved for 5 days. To reach the recorded version please dial +44 (0) 20 8288 4459 and use code 647782 from 13.00 SE time.

For further information, please contact:

Jonas Frick, CEO, Medivir, +46 8 608 3117 or Rein Piir, CFO/VP IR, Medivir, +46 8 608 3123, +46 708 53 7292

About the Medivir group

Medivir is an innovative and specialized research company active in the pharmaceuticals sphere, located in Cambridge, UK, and Huddinge, Sweden. Medivir's research focuses on the development of new pharmaceutical compounds as inhibitors of target enzymes with protease or polymerase activity.

The group comprises Medivir AB, the subsidiaries Medivir UK Ltd. and CCS AB, plus second-tier subsidiaries CCS (UK) Ltd. and Nordic Care Sweden AB. Medivir has been listed on the Stockholm Stock Exchange since 1996.

The research portfolio includes projects against HIV, jaundice, shingles, cold sores, osteoporosis, rheumatoid arthritis, asthma, multiple sclerosis and organ/graft rejection.

Medivir has four projects in clinical development. Of these, two are moving towards Phase III trials after having completed Phase II trials. One is in Phase I and one is in Phase II.

Medivir's pre-clinical research encompasses a number of projects, of which one is on its way towards and two are in the lead optimization phase and one is in the late pre-clinical development stage. Furthermore, ten activities are in the explorative stage.

For more information about Medivir, visit the company's web site at www.medivir.com

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