PRESS RELEASE: OctoPlus presents positive Phase IIa study results for Locteron in hepatitis C at AASLD conference

OctoPlus presents positive Phase IIa study results for Locteron in hepatitis C at AASLD conference

OctoPlus, the drug delivery and development company, announces that full and complete results from its successful SELECT-1 Phase IIa clinical trial of Locteronâ„¢ for the treatment of chronic hepatitis C will be presented today at the 58th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD).

Viral kinetic modeling of the SELECT-1 results by Eva Herrmann, Ph.D. and Stefan Zeuzem, M.D. of Saarland University Hospital, Homburg/Saar, Germany, demonstrated a statistically significant dose response. The study results also showed that patients receiving Locteron experienced side effects that were less frequent and less severe than those previously reported in clinical trials for the currently marketed pegylated interferons and for a development-stage product, Albuferon®.

OctoPlus is co-developing Locteron with its partner Biolex Therapeutics. SELECT-1 (Safety and Efficacy of Locteron: European Clinical Trial-1) was designed to evaluate four different doses of Locteron, 160, 320, 480 and 640 micrograms (ug), administered once-every-two-weeks in combination with ribavirin administered orally twice per day in 32 treatment-naïve hepatitis C patients with the genotype-1 variant of the virus.

SELECT-1 results demonstrate Locteron’s strong antiviral effect:
- A statistically significant dose response was observed in the study, and viral kinetic modeling by Drs. Herrmann and Zeuzem also demonstrated a statistically significant reduction in viral RNA during the entire 12-week treatment period. Specifically the dose effect was associated with mean and maximal antiviral efficiency of Locteron (p=0.003 and p=0.006, respectively; Jonckheere-Terpstra-Test).
- Average viral reduction after 12 weeks of treatment was greater than four logs for each of the 640, 480 and 320 ug doses, compared to 1.8 logs for the lowest dose of 160 ug.
- The percentage of patients who achieved early virologic response (EVR), defined as at least a two-log reduction in hepatitis C virus, was 100% in the 640 and 480 ug dose cohorts and 88% in the 320 ug dose cohort, compared to 37.5% in the 160 ug dose cohort. The results compare favorably with results previously reported in clinical trials for the currently marketed pegylated interferon alfa products and for Albuferon for which EVR rates ranging from approximately 74% to 90% in clinical trials have been reported.

SELECT-1 results confirm Locteron’s superior tolerability:
- Locteron was well tolerated at all doses.
- Approximately 90% of adverse events were rated as mild.
- There were no serious adverse events in the 160, 320, and 480 ug dose cohorts.
- There was one serious adverse event in the 640 ug cohort. This was a case of inflammation of the ear, which completely resolved.

The majority of the side effects experienced by patients treated with Locteron in the SELECT-1 study appear to be less frequent and less severe than the side effects reported in previous clinical trials for pegylated interferons and Albuferon. For example, only one patient (3%) in the SELECT-1 study receiving Locteron experienced a clinical adverse event rated as severe, indicating an improvement over previously reported incidences of 14% and 18% in clinical trials for Pegasys® and Albuferon, respectively. In addition, serious adverse events in SELECT-1 were limited to the one event discussed above.

Injection site reactions were reported in 41% of the patients in SELECT-1. All injection site reactions were mild with the exception of one patient in the 640 ug cohort who had a reaction rated as moderate. The SELECT-1 results are within the range of the incidence of injection site reactions reported in clinical trials of Intron®-A, PEG-Intron and Pegasys of 49%, 75% and 22%, respectively.

For further information, please contact:
Rianne Roukema, Corporate Communications: +31 (71) 524 1071

Notes to editors:

About Locteron
Locteron is designed to be a best-in-class therapeutic for patients with chronic hepatitis C, with the potential to induce less side effects, improve patient compliance and provide a more convenient once-every-two-week dosing schedule compared with current therapies. Locteron combines OctoPlus’ proprietary PolyActive™ drug delivery technology with BLX-883, a recombinant alfa interferon produced by OctoPlus’ co-development partner Biolex Therapeutics in its patented LEX SystemSM. Locteron is produced in OctoPlus’ cGMP manufacturing facilities in Leiden, the Netherlands.

OctoPlus and Biolex plan to commence SELECT-2, a Phase IIb trial of Locteron in the middle of 2008. The 12-week results of the Phase IIb trial will be used as the basis for dose selection for the commencement of the Phase III development program.

About OctoPlus
OctoPlus N.V. 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.

Our pipeline consists of 5 products in preclinical and clinical development. Our lead product is Locteron, a sustained-release formulation of interferon alfa for the treatment of chronic hepatitis C, which we are co-developing with Biolex Therapeutics. Locteron has successfully completed Phase IIa clinical development. Furthermore, our pipeline comprises a product for the treatment of chronic middle ear infection, which is in Phase II development, a pre-clinical GLP-1-analogue product for the treatment of diabetes and two preclinical-stage single-shot vaccines.

In addition, OctoPlus is a leading 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 in injectable formulations. The earnings and expertise that we derive from rendering formulation and manufacturing services help to support our own drug development programs.

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

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