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"Monoclonal antibody BT-061 shows efficacy in patients with rheumatoid arthritis"

• Unblinded data from analysis of 40 patients in a clinical Phase II trial indicates efficacy and good tolerability • Positive response rates at week 9 (after 8-week treatment) in patients receiving treatment with BT-061 in combination with methotrexate (MTX)

Dreieich, 20th October 2009. In the unblinded first part of a Phase II combination trial with methotrexate, the Biotest Group’s BT-061 monoclonal antibody provided positive results in the indication of rheumatoid arthritis (RA). As part of this clinical trial, so far the data of 40 patients with acute, moderate to severe RA, with inadequate response to one or more disease-modifying antirheumatic drugs (DMARDs) have been analysed.

Patients included in the clinical trial were randomly assigned to three different treatment groups in a ratio of 1:3:1. For a period of 8 weeks, 8 patients received by weekly intravenous application 0.5mg of BT-061 and 24 patients 2.0mg of BT-061, both groups in combination with methotrexate, a substance commonly used in the treatment of RA. The 8 patients in the placebo group only received methotrexate. The response rate of patients at week 9 (after 8 weeks of treatment) was evaluated on the basis of the ACR score, the internationally accepted standard rating system developed by the American College of Rheumatology.

In the group receiving 2mg of BT-061, the efficacy at week 9 was higher than in the 0.5mg group and the placebo arm. In 75% of patients of the 2mg group symptoms improved by 20% (ACR 20 response), compared with 50% of patients in the placebo group. A reduction in symptoms of at least 50% was achieved in 41.7% of patients receiving the combination therapy (ACR 50: 41,7%) and 16.7% of patients showed an improvement of symptoms of a minimum of 70% (ACR 70: 16.7%). For treatment with methotrexate alone (placebo group), the relevant values were 25% and 0% respectively. The relatively high response rate of the placebo drug is most probably caused by the simultaneous administration of methotrexate, known to be effective in the treatment of RA.

According to the clinical trial protocol, additional patient data will now be unblinded and analysed within the next weeks. Additional 40 patients will then be included in part 2 of this clinical trial and treated subcutaneously with 50mg of BT-061 in combination with methotrexate. The subcutaneous application of biotherapeutics enables patients to self-medicate at home after marketing authorisation.

Furthermore, the results demonstrated the good overall tolerability of BT-061. No serious side effects caused by the drug were observed. There was no need to discontinue infusion of BT-061 in any patient due to undesirable effects. The comprehensive data from parts 1 and 2 as well as the detailed analysis of the clinical trial, which in addition to the efficacy data also comprises data on pharmacokinetics, pharmacodynamics and a profile of possible side effects, will be presented to experts in the context of international conferences following completion of the second part of the trial.

ACR response rates/scores The ACR score is based on a scoring system developed by the American College of Rheumatology (ACR) to evaluate the response of patients to antirheumatic therapies. This standard validation method measures the percentage improvement of a series of symptoms and parameters that are specific to the disease to determine the medical condition of patients. An ACR of 20, for example, reflects a 20% decrease in symptoms. A reduction of 50% or 70% in RA symptoms is described with ACR 50 and ACR 70 respectively.

Disclaimer This document contains forward-looking statements on overall economic development as well as on the business, earnings, financial and assets position of Biotest AG and its subsidiaries. These statements are based on current plans, estimates, forecasts and expectations of the company and are thus subject to risks and elements of uncertainty that could result in significant deviation of actual developments from expected developments. The forward-looking statements are only valid at the time of publication. Biotest does not intend to update the forward-looking statements and assumes no obligation to do so.

About Biotest Biotest is a provider of pharmaceutical and biotherapeutic drugs as well as reagents and systems for diagnostics and microbiology. With a value added chain that extends from pre-clinical and clinical development to worldwide sales, Biotest has specialised primarily in the areas of application of immunology and haematology. In its Plasma Protein segment, Biotest develops and markets immunoglobulins, coagulation factors and albumins based on human blood plasma. These are used for diseases of the immune and haematopoietic systems. In the Biotherapeutic segment, Biotest researches into the clinical development of monoclonal antibodies, including in the indications of rheumatoid arthritis and cancer of plasma cells. The products of the Microbiological Monitoring segment are primarily used in hygiene monitoring, while those of Medical Diagnostics are used, for example, in blood transfusions and transplants.

Biotest has more than 2,000 employees worldwide. The preference shares of Biotest AG are listed in the SDAX on the Frankfurt stock exchange.

Biotest AG, Landsteinerstr. 5, D-63303 Dreieich, Dr. Monika Buttkereit tel.: +49 (0) 6103 801-4406, e-mail: fax: +49 (0) 6103 801-347 Securities’ ID No., ISIN ordinary shares: 522720, DE0005227201 Securities’ ID No., ISIN preference shares: 522723, DE0005227235 Listing: Prime Standard/Official traded Frankfurt, Berlin, Düsseldorf, Hamburg, Stuttgart

Posted: October 2009