Prescribing guidelines produced for new anti-rheumatic drugs
Guidelines setting out how and when to prescribe tumour necrosis factor (TNF) blockers for treating rheumatoid arthritis have been produced by the British Society for Rheumatology.
The BSR says that the guidelines were designed to ensure that new treatments are introduced in a systematic and planned way. They are based on published clinical trial data and cover the two TNF blockers that are currently available, etanercept and infliximab. (Only etanercept is licensed for treating rheumatoid arthritis at present.) They recommend that TNF blockers are only prescribed in secondary care.
In terms of clinical efficacy, the guidelines state: "Although both etanercept and infliximab appear to be more effective than standard therapy, their use cannot be justified in patients who might respond equally well to much cheaper conventional therapy with sulphasalazine or methotrexate with which there is extensive long-term clinical experience." Trials of combination therapy have shown that "methotrexate and TNF blockers are synergistic and the data show that combining the two agents in methotrexate-resistant patients results in a substantial response rate."
The guidelines specify who should be receiving the new drugs. Such patients include those with highly active RA, calculated by a composite disease activity score. Alternatively, patients could have failed on standard therapy for RA. This would involve treatment failure with at least two disease modifying anti-rheumatic agents. The guidelines also specify exclusion criteria for TNF blocker treatment, including pregnancy, breast feeding, patients with or at high risk of infection and patients with malignancy or pre-malignancy states. The guidelines discuss criteria, such as adverse events and inefficacy, for the withdrawal of therapy.
The BSR is advising that a central registry of all patients treated with TNF blockers is set up in order to monitor use, benefit and side effects of the drugs. It will study both the short- and long-term toxicity of these drugs, in particular the incidence of serious infections, the development of malignancies and mortality.
Infections have been seen in the US, mostly in patients predisposed to infections, the BSR says. It adds that the mode of action of TNF blockers gives a theoretical risk of immunosuppression and malignancy.
Launching the guidelines on June 8, Dr Andrew Bamji (chair of the working party) said: "If these treatments prove their worth there could be a strong case for increasing the drugs budget. This will mean higher costs at first, but might lead to real savings in the long term. The demand for other expensive services could be dramatically reduced, including fewer joint replacements and less demand for physiotherapy, occupational therapy and podiatry services."
The BSR says that the guidelines will be reviewed and revised as new evidence becomes available and will be posted on the BSR website (http://www.rheumatology.org.uk).
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Citation: The Pharmaceutical Journal