Abatacept - Treatment for Rheumatoid Arthritis

Key Data

Abatacept (Orencia) was developed by Bristol-Myers-Squibb for the treatment of rheumatoid arthritis (RA). It is a biologic drug that contains a selective co-stimulation modulator.

The US Food and Drug Administration approved the drug in December 2005 followed by the European Commission in July 2010.

Rheumatoid arthritis

RA is a long-lasting, painful autoimmune disorder that can affect organs and tissues within the body, especially synovial joints.

The progression of the disease leads to ankylosis and articular cartilage of the joints. The disease can also cause diffusing pains in the pericardium, nodular lesions, sclera, pleura and the lungs. It is a disabling and inflammatory condition that may lead to a loss of mobility.

The disease affects about 1% of the world's population, with women three times more likely than men to have it. About 75% of diagnosed RA patients are women. The disease can affect people of any age but more so in the 40-50 bracket.

"The drug is a protein with immunoglobulin that contains a T-cell co-stimulation modulator."

Targeting the disease

Abatacept is a prescription medicine developed to treat RA. The drug is a protein with immunoglobulin that contains a T-cell co-stimulation modulator. The activated T-cells play an organising role in the immunopathological mechanisms of RA. Inhibiting full activation of T-cells is, therefore, necessary for treating RA. The drug works by selectively modulating a co-stimulatory signal that is necessary for T-cell activation. The drug is developed by applying recombinant DNA technology.

Clinical trials

Bristol-Myers-Squibb began Phase I clinical trials in 2004-05. The objective of the trial was to study and estimate the tolerability and safety of the drug. Twenty-five RA patients were enrolled for treatment with single and multiple doses of Abatacept. The results of the study showed good tolerability in RA patients who were given single and multiple doses of the drug.

Phase II trials were conducted between January 2006 and May 2007. Sixty-eight RA patients were enrolled for the study and were given either a placebo or Abatacept for the treatment. The results showed that 51 Abatacept-treated subjects were seropositive for anti-Abatacept antibodies.

The efficacy and safety of Abatacept was studied in clinical trials by enrolling more than 2,600 RA patients. The trials included placebo-controlled and open-label extension periods.

"The efficacy and safety of Abatacept was studied in clinical trials by enrolling more than 2,600 RA patients."

Phase III clinical trials started in April 2007 and concluded in July 2008. The trial included three major studies on AIM (Abatacept in Inadequate responders to Methotrexate), ATTAIN (Abatacept Trial in Treatment of Anti-TNF INadequate responders) and ASSURE (Abatacept Study of Safety in Use with other RA therapies).

Phase III pivotal and efficacy studies of the drug showed a significant improvement in signs and symptoms of RA patients. The American College of Rheumatology measured the results by using 20, 50 and 70 scores.

The results of the study indicated that the patients administered with Abatacept showed an improved difference from placebos by day-15 for ACR 20 in some patients.

The phase III study included a questionnaire which assessed how Abatacept users improved in eight quality-of-life domains when compared with placebo patients. A significant portion of Abatacept patients achieved an ACR 70 score for six months in comparison with methotrexate. Structural damage also decelerated in these patients.

Marketing commentary

Sales of Abatacept have increased steadily in the US since 2006. Moreover, in June 2010, Pfizer decided to stop the development of one of the two investigational drugs that it is manufacturing with Trubion Pharmaceuticals for treating RA.

RA is a painful autoimmune disorder that affects the tissues and organs.

The disease may lead to a loss of mobility.

RA affects about 1% of the world's population.