Arana Therapeutics Limited announced positive results from its phase-II trial of ART621 in patients with stable plaque psoriasis. The primary endpoint was met with repeat doses of ART621 being well tolerated and exhibiting a safety profile consistent with anti-TNF activity, the method of administration and the underlying study population. Arana will continue clinical development of ART621with two ongoing phase-II trials for rheumatoid arthritis (RA) in combination with methotrexate.

Secondary findings from the study provided insight into the efficacy, immunogenicity and pharmacokinetics of ART621. While the study was not designed to demonstrate efficacy, evidence of some anti-TNF activity was seen. A total of four subjects in the ART621 group achieved a 50 per cent reduction in Psoriasis Area and Severity Index (PASI) score at week 12 compared to zero in the placebo group. One of these ART621 subjects also achieved a 90 per cent PASI reduction.

No human anti-ART621 antibody responses were detected for up to four weeks after the last injection, suggesting inherently low immunogenicity of the drug. Consistent with prior phase-1 data, ART621 exhibited a half life of approximately 14 days, which compares favourably to market leading anti-TNF products.

"We are pleased with the outcome of our phase-II study which has provided us with the confidence to continue clinical development of ART621. The data indicate that ART621 possesses anti-TNF activity, was well tolerated and has a competitive half life. Importantly we did not see any antibody responses against ART621 and this may be an important differentiator commercially, as other anti-TNF products may have their efficacy reduced by such responses," said Steffen Nock, acting chief executive officer.

"ART621 is now at an exciting stage with an open IND, encouraging clinical data, scale up of manufacturing progressing well and ongoing clinical trials in RA."