Amgen announced that phase 3 study evaluating efficacy and safety of biosimilar candidate ABP 501 compared with Humira (adalimumab) in patients with moderate-to-severe plaque psoriasis met its primary endpoint. The primary endpoint was the Psoriasis Area and Severity Index (PASI) percent improvement from baseline to week 16 of treatment. At week 16, the PASI percent improvement from baseline was within the prespecified equivalence margin for ABP 501 compared to adalimumab. Safety and immunogenicity of ABP 501 were comparable to adalimumab. This is the first of two phase 3 studies intended to form the basis for global regulatory submissions for ABP 501.

ABP 501 is being developed as a biosimilar to adalimumab, an anti-TNF-a  monoclonal antibody, which is approved in many countries for the treatment of inflammatory diseases, including rheumatoid arthritis, plaque psoriasis (PsO), polyarticular juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease and ulcerative colitis.

"Results from Amgen's biosimilar phase 3 plaque psoriasis study met the primary endpoint for efficacy and showed comparable safety and immunogenicity to adalimumab, which further demonstrates the Company's commitment to provide patients with access to high-quality medicines," said Sean E. Harper, M.D., executive vice president of research and development at Amgen. "We look forward to continuing to leverage our experience and expertise in biotechnology to bring biosimilars to patients."

Amgen has six biosimilar molecules in development and expects to launch the portfolio starting in 2017.

This randomised, double-blind, active-controlled study (study number 20120263) evaluated safety and efficacy of ABP 501 compared to adalimumab in adult patients with moderate-to-severe plaque PsO. There were 350 patients enrolled and initially randomised. Among them, there were 174 patients in the ABP 501 group and 173 patients in the adalimumab group treated. One patient in the ABP 501 group and two patients in the adalimumab group were randomised but did not receive any investigational product. The primary endpoint, PASI percent improvement, was evaluated at week 16. The PASI is a measure of the average redness (erythema), thickness (induration), and scaliness (scaling; each graded on a 0-4 scale) of the lesions, weighted by the area of involvement. All assessments for a given patient were made by the same observer whenever possible.

At week 16, patients with a PASI 50 or above response will remain on study for up to 52 weeks. Patients continuing on study beyond week 16 were re-randomised in a blinded fashion such that all patients initially randomised to ABP 501 continued to receive ABP 501 and those on adalimumab either continued on adalimumab or switched to ABP 501 in a 1:1 fashion.  Patients will continue on treatment until week 48, when the patients will receive the last dose of investigational product. The final efficacy assessments will be conducted at week 50 and the study will end at week 52.

Psoriasis is a non-contagious chronic disease in which the immune system causes skin cells to grow at an accelerated rate.1 Instead of being shed, skin cells pile up, causing painful and itchy, red, scaly patches. Approximately 125 million people worldwide have psoriasis, and 80 per cent of those patients have plaque psoriasis.

ABP 501 is being developed as a biosimilar candidate for adalimumab, an anti-TNF-a monoclonal antibody which is approved in many regions for the treatment of several inflammatory diseases. The active ingredient of ABP 501 is an anti-TNF-a monoclonal antibody which has the same amino acid sequence as adalimumab. ABP 501 has the same pharmaceutical dosage form and strength as adalimumab (US) and adalimumab (EU).

Amgen Biosimilars is committed to building upon Amgen's experience in the development and manufacturing of innovative human therapeutics to expand Amgen's reach to patients suffering from serious illnesses. Biosimilars offer the potential to increase patient access to vital medicines, and Amgen is well positioned to leverage its more than 30 years of experience in biotechnology to create high-quality biosimilars and reliably supply them to patients worldwide.