FDA ( U.S. Food and Drug Administration ) approved Humira ( Adalimumab ) for reducing signs and symptoms of active arthritis in patients with psoriatic arthritis, a chronic disease that combines the symptoms of arthritis, including joint pain and inflammation, with those of psoriatic skin disease, such as dry, scaly skin.

Psoriatic arthritis is a serious autoimmune disease and few available treatment options address the potentially devastating combination of symptoms affecting both the skin and joints.
Psoriatic arthritis is the first new disease indication for Humira beyond rheumatoid arthritis.

The Humira approval is based on results of the Adalimumab Effectiveness in Psoriatic Arthritis Trial ( ADEPT ), which is the largest biologic trial in psoriatic arthritis.

ADEPT studied 313 adult patients with moderately to severely active psoriatic arthritis who had an inadequate response to NSAID ( non-steroidal anti-inflammatory drug ) therapy.

The patients, treated with Humira, experienced significantly greater improvement in both joint and skin disease symptoms than placebo-treated patients at 24 weeks.
Improvements in both skin lesions and joint symptoms were seen as early as two weeks after initiation of treatment and continued to improve over time.

Patients' arthritic symptoms also responded to Humira, with nearly 60 percent of patients achieving ACR20 at week 12, one of the study's primary endpoints, and with a sustained response through week 24.
ACR70, a more stringent response criterion, was achieved by nearly 25 percent of patients treated with HUMIRA vs. 1 percent of patients treated with placebo at week 24.

American College of Rheumatology ( ACR ) scores measure the percentage of improvement in tender and swollen joint count and several other clinical measures.

" Clinical improvement in arthritic symptoms that can lead to disability as well as the pain and stiffness that keeps patients from functioning normally was rapid and significant with Adalimumab," said rheumatologist Philip Mease, Swedish Medical Center and University of Washington School of Medicine, Seattle, and lead investigator of the ADEPT study.

Clinical trial data from ADEPT showed the ability of Humira to improve both the skin and joint symptoms associated with psoriatic arthritis.
Among the 69 patients in the trial who had skin lesions involving greater than 3 percent body surface area ( the palm of an adult hand represents approximately 1 percent of the body's skin surface ) who were treated with Humira, three out of four achieved PASI 50 ( 75 percent ), three out of five achieved a PASI 75 ( 59 percent ) and two out of five ( 42 percent ) achieved a PASI 90 response at 24 weeks, which reflects at least 50, 75 or 90 percent improvement in skin symptoms assessed by the Psoriasis Area and Severity Index ( PASI ).

The recommended dose of Humira for psoriatic arthritis is 40 mg every other week by subcutaneous injection, the usual dose used for Humira in the treatment of moderate to severe rheumatoid arthritis ( RA ).

The rates of adverse events and serious adverse events in the ADEPT trial were comparable with other Humira RA clinical trials.
Among patients taking Humira, the most common adverse events ( those affecting at least 5 percent of patients ) were upper respiratory infection, nasopharyngitis, injection site reaction, headache and hypertension.
The safety profile of Humira in the ADEPT clinical trial was similar to that observed in the Humira RA clinical trials.

Psoriatic arthritis combines skin symptoms, such as dry, scaly skin and patches of red, raised skin known as plaques, with arthritis symptoms including joint pain and inflammation.
Common symptoms of psoriatic arthritis include varying degrees of skin involvement along with stiffness, pain, swelling and tenderness of the joints that can lead to a reduced range of motion and potential severe joint destruction.
Left untreated, psoriatic arthritis can be a progressively disabling disease. The arthritic manifestations often include debilitating disease of the hands and feet, as seen in rheumatoid arthritis, as well as painful inflammation of the tendon insertions and arthritis of the spine.
Psoriatic arthritis is most often found in patients who suffer from psoriasis, a chronic skin disease that affects nearly 3 percent of the world's population. It is estimated that up to 30 percent of people with psoriasis also develop psoriatic arthritis.
Like rheumatoid arthritis, psoriatic arthritis is an autoimmune disorder in which a human protein, tumor necrosis factor-alpha ( TNF-alpha ), has been suggested to play a role in disease development. Humira, which is a fully human monoclonal antibody that resembles antibodies normally found in the body, works by specifically blocking TNF-alpha.

Cases of tuberculosis ( TB ) have been observed in patients receiving Humira.
Serious infections and sepsis, including fatalities, have been reported with the use of TNF-blocking agents, including Humira. Many of these infections occurred in patients also taking other immunosuppressive agents that in addition to their underlying disease could predispose them to infections.
Treatment with Humira should not be initiated in patients with active infections.

The combination of Humira and Kineret ( Anakinra ) is not recommended.

TNF-blocking agents, including Humira, have been associated in rare cases with demyelinating disease and severe allergic reactions.
Infrequent reports of serious blood disorders have been reported with TNF-blocking agents.
More cases of malignancies have been observed among patients receiving TNF blockers, including Humira, compared to control patients in clinical trials.
These malignancies, other than lymphoma and non-melanoma skin cancer, were similar in type and number to what would be expected in the general population. There was an approximately four fold higher rate of lymphoma in combined controlled and uncontrolled open label portions of Humira clinical trials. The potential role of TNF-blocking therapy in the development of malignancies is not known.

The most frequent adverse events seen in the placebo-controlled clinical trials in rheumatoid arthritis ( Humira vs. placebo ) were injection site reactions ( 20 percent vs. 14 percent ), upper respiratory infection ( 17 percent vs. 13 percent ), injection site pain ( 12 percent vs. 12 percent ), headache ( 12 percent vs. 8 percent ), rash ( 12 percent vs. 6 percent ) and sinusitis ( 11 percent vs. 9 percent ).
Discontinuations due to adverse events were 7 percent for Humira and 4 percent for placebo.

Source: Abbott, 2005


XagenaMedicine2005