• Final results of the first repeated dose phase II trial in Chronic Plaque Psoriasis show efficacy in the higher subcutaneous dose groups
  • Good tolerability confirmed
  • Further development in Psoriasis will be based on results of larger clinical trials in Rheumatoid Arthritis

DREIEICH, Germany I November 24, 2011 I In its collaboration with Abbott, Biotest AG is pursuing an innovative therapeutic strategy to treat the autoimmune disorders Rheumatoid Arthritis and Chronic Plaque Psoriasis using the monoclonal antibody Tregalizumab (BT-061).

A phase IIa clinical trial with repeated doses has been completed in which Tregalizumab was tested for the treatment of chronic plaque psoriasis.

This trial was a placebo-controlled, double-blind, multicentre, multinational, multiple dose, dose-escalation study to evaluate the safety and efficacy of BT-061 in different doses and mode of administrations. Patients were treated subcutaneously or intravenously weekly for eight consecutive weeks in six different escalating dose groups. The primary endpoint of the study was PASI 75 (PASI : Psoriasis Area and Severity Index) response at Week 9, with PASI 50 and PASI 90 responses at Week 9 as secondary endpoints.

49 patients with Chronic Plaque Psoriasis were enrolled. Patients received Tregalizumab as monotherapy at doses between 25-100 mg as subcutaneous injections or 0.5 and 2 mg as intravenous infusions. Tregalizumab was administered once weekly for 8 weeks. In each treatment group, six patients received active treatment and two patients received placebo. After the treatment period, the patients were observed for further 12 weeks without Tregalizumab treatment (follow-up period).

Highest clinical response measured by the PASI score was achieved in the 100 mg dose-group. 71.4% of patients experienced at least a 50% improvement in psoriasis signs and symptoms as measured by PASI (PASI 50) at week 9, compared with 37.5% of those who received placebo. At the same time, in this dose-group, 42.9% of patients receiving active drug had an improvement of at least 75% (PASI 75) vs 12.5% for placebo.

In analogy to the results of the previous Phase I/II trial Study 967 (single dose administration), also in study 973 in the relevant active dose-groups, the PASI score generally further improved after the end of the 8 week treatment period. Further improvement of up to 90% (PASI 90) was observed in several patients during the treatment and follow-up period. The evaluation of response within the treatment and follow-up period (best response) showed a PASI 50 improvement in 71.4%, a PASI 75 in 57.1% and a PASI 90 in 14.3% of patients in the 100 mg SC dose-group. The respective numbers in the corresponding placebo group were 37.5%, 25.0%, and 0.0% (PASI 50, PASI 75, and PASI 90).

The good tolerability of Tregalizumab, which was expected based on the data from previous trials, has also been confirmed in the concluded phase IIa trial.

Further studies in Psoriasis in larger patient groups with a less frequent dosing schedule and a longer treatment period for Tregalizumab will only be started after finalisation of phase IIb trials in Rheumatoid Arthritis.

Further information

Tregalizumab (BT-061):

Tregalizumab enhances a natural mechanism of down regulating excessive immune responses and is therefore developed to treat disease conditions that originate from an overreaction of the immune system.

Currently, clinical development of Tregalizumab aims at investigating the clinical efficacy and safety of Tregalizumab in the indications Rheumatoid Arthritis and Psoriasis. Based on the data obtained so far, promising efficacy and an overall good safety and tolerability in both lead indications could be demonstrated. Five clinical trials with Tregalizumab have been concluded. A confirmatory Phase II trial in Rheumatoid Arthritis is currently recruiting patients.

Plaque Psoriasis:

Chronic Plaque Psoriasis affects 1-3 % of the population in Europe and North America and is characterised by an excessive stimulation of growth of the keratinocytes, the most frequent cell type in the epidermis (the top layer of the skin). Clinical manifestations comprise large scaly and itchy patches and redness of the skin. Psoriasis is associated with an increased prevalence of long-term complications such as Psoriatic Arthritis, Cardiovascular Diseases or Diabetes.

Psoriasis Area and Severity Index (PASI) is the most widely used tool for the measurement of severity of psoriasis. PASI combines the assessment of the severity of lesions and the area affected into a single score

To make up the score, the three features (redness, thickness, and scaliness) of psoriatic lesions are each assigned a number from 0 to 4 with 4 being worst. The extent of involvement of each region of the body is scored from 0 to 6. Adding up the scores give a range of 0 to 72.

SOURCE: Biotest