OctoPlus’ Licensee Biolex Therapeutics Presents Locteron Phase IIa Results at EASL Conference

LEIDEN, NETHERLANDS--(Marketwire - April 24, 2009) - OctoPlus N.V. ("OctoPlus" or "the Company") (Euronext: OCTO) announces today that its licensee Biolex Therapeutics (see separate Biolex press release on www.biolex.com) will present the results from its United States Phase IIa clinical study (the "PLUS" study) with Locteron® today at the 44th Annual Meeting of the European Association for the Study of the Liver (EASL) in Copenhagen, Denmark. Results of this study suggest that Locteron may result in less frequent flu-like symptoms when compared to pegylated interferon products.

The PLUS Phase IIa clinical study was conducted in the United States in 32 chronic hepatitis C patients who had failed prior treatment. The study was designed to evaluate the safety and tolerability of Locteron, and to directly compare Locteron with the current standard of care. Patients were randomised to receive either Locteron (administered once every two weeks) or PEG-Intron® (administered once per week). The Locteron doses evaluated in the PLUS study were 320 µg and 640 µg, and patients also received oral, weight-based ribavirin. Patients were treated for four weeks with an additional two weeks of follow up evaluation.

Flu-like symptoms were reported to be less frequent and milder in both of the Locteron cohorts of the study. The total severity score for flu-like symptoms for patients in the 320 µg cohort of Locteron was 80% lower than the severity score for the PEG-Intron cohort (severity score was based on number of occurrences adjusted for severity rating of adverse event). The total severity score for patients in the 640 µg cohort of Locteron was 30% lower than the severity score for the PEG-Intron cohort. Injections site reactions and common hematological parameters among the Locteron cohorts and the PEG-Intron cohorts were comparable. Anti-viral effects were also comparable among the Locteron and PEG-Intron cohorts.

Simon Sturge, CEO of OctoPlus: "These results support Locteron's potential improved tolerability profile that has been suggested in previous clinical studies and further validate the added value of our controlled release drug delivery technologies in the development of improved injectable therapeutics."

Locteron is an investigational therapeutic candidate and has not been approved for sale by the United States Food and Drug Administration or by any international regulatory agency.

About Locteron

Locteron is a controlled release interferon alpha designed to improve patient care in the treatment of hepatitis C through a more favorable side-effect profile and dosing convenience compared to existing pegylated interferon products. In contrast to Locteron's controlled release mechanism, the currently approved products Pegasys® and PEG-Intron, and the investigational product Albuferon® are immediate release products that lack a controlled release mechanism. Interferon alpha serves as the foundation of current combination therapy for hepatitis C patients, and all major hepatitis C drug candidates currently in clinical trials are being studied in combination with interferon alpha. It is estimated that worldwide sales of interferon products for the treatment of hepatitis C will approach US$ 6 billion by 2016.

Locteron combines OctoPlus' proprietary drug delivery technology PolyActive® with BLX-883, a recombinant interferon alpha produced by Biolex in its patented LEX System(SM). Locteron is configured to allow dosing once every two weeks, more convenient than Pegasys and PEG-Intron, each of which require dosing every week. More importantly, Locteron's controlled release mechanism results in the gradual release of interferon alpha to patients over the duration of two weeks and avoids the early peak blood plasma levels of the active interferon that characterise pegylated interferons and Albuferon. This controlled release mechanism is designed to reduce the frequency, duration and severity of side effects, including flu-like symptoms, commonly experienced by patients treated with pegylated interferons and with Albuferon.

Three clinical trials with Locteron have been completed to date, and a Phase IIb study is currently ongoing in 100 chronic genotype-1 hepatitis C patients in the United States and Europe.

About Biolex Therapeutics

Biolex is a clinical-stage biopharmaceutical company that uses its patented LEX System(SM) to develop hard-to-make therapeutic proteins and to optimize monoclonal antibodies. The LEX System is a novel technology that genetically transforms the aquatic plant Lemna to enable the production of biologic product candidates.

About OctoPlus

OctoPlus is a product-oriented biopharmaceutical company committed to the creation of improved pharmaceutical products that are based on OctoPlus' proprietary drug delivery technologies and have fewer side effects, improved patient convenience and a better efficacy/safety balance than existing therapies. Rather than seeking to discover novel drug candidates through early stage research activities, OctoPlus focuses on the development of long-acting, controlled release versions of known protein therapeutics, other drugs, and vaccines on behalf of its clients.

The clinically most advanced product incorporating our technology is Biolex Therapeutics' lead product Locteron, a controlled release formulation of interferon alpha for the treatment of chronic hepatitis C. Locteron is being manufactured for Biolex by OctoPlus and is currently in Phase IIb clinical studies.

In addition, OctoPlus is a leading European provider of advanced drug formulation and clinical scale manufacturing services to the pharmaceutical and biotechnology industries, with a focus on difficult-to-formulate active pharmaceutical ingredients.

OctoPlus is listed on Euronext Amsterdam by NYSE Euronext under the symbol OCTO. For more information about OctoPlus, please visit our website www.octoplus.nl.

This document may contain certain forward-looking statements relating to the business, financial performance and results of OctoPlus and the industry in which it operates. These statements are based on OctoPlus' current plans, estimates and projections, as well as its expectations of external conditions and events. In particular the words "expect", "anticipate", "predict", "estimate", "project", "plan", "may", "should", "would", "will", "intend", "believe" and similar expressions are intended to identify forward-looking statements. We caution investors that a number of important factors, and the inherent risks and uncertainties that such statements involve, could cause actual results or outcomes to differ materially from those expressed in any forward-looking statements. In the event of any inconsistency between an English version and a Dutch version of this document, the English version will prevail over the Dutch version.

Click here for the press release in PDF: http://hugin.info/137076/R/1307831/301229.pdf