Sales of efalizumab (Raptiva®) suspended

The Health Sciences Authority (HSA) has requested Merck Pte Ltd to suspend the sales of efalizumab (Raptiva®) in Singapore with effect from 26 February 2009 due to the emergence of new safety issues associated with the product.

Raptiva® is available locally as a prescription medicine. It contains the active ingredient, efalizumab, an immunomodulating, humanized monoclonal antibody, licensed for the treatment of adult patients with moderate to severe chronic plaque psoriasis who are candidates of phototherapy or systemic therapy.

Risk-benefit assessment of Raptiva®

HSA and its Pharmacovigilance Advisory Committee has assessed the relevant data available to date which included the recent adverse reports of Progressive Multifocal Leukoencephalopathy (PML) and the limited place in therapy of Raptiva® in the local setting and concluded that the risk versus benefit of Raptiva® is no longer favourable. The review took into consideration the risks of potentially fatal PML associated with Raptiva® countered with the fact that it is not a first-line therapy, that it is used in a potentially serious but non-life threatening condition, and the availability of other treatment options for plague psoriasis. Besides PML,Raptiva® is also associated with serious adverse effects such as Guillain-Barre and Miller-Fisher syndromes, encephalitis, encephalopathy, meningitis, sepsis and opportunistic infections.

PML is a rare neuromuscular disease caused by opportunistic infections that usually leads to severe disability or death. There is no reliable way of knowing which patients will develop PML or when the disease is likely to occur. To date, there are four worldwide reports of PML (three virologically confirmed and one suspected) associated with the product in patients who had been continuously treated with Raptiva® for three or more years. Two of the three confirmed cases resulted in the patient's death. Locally, the HSA has not received any adverse drug reaction reports associated with Raptiva®.

Regulatory actions taken by international agencies

The sale of Raptiva® has been recently suspended in Europe and Canada by the European Medicines Agency (EMEA) and Health Canada respectively. Both agencies have also considered the risk-benefit profile of Raptiva® to be unfavourable.

The US Food and Drug Administration (US FDA) is currently reviewing the latest information about Raptiva® and has committed to take appropriate steps to ensure that the risks of Raptiva® do not outweigh its benefits. In October 2008, the US product labeling for Raptiva® was revised to highlight in a boxed warning the risks of life-threatening infections, including PML. A risk evaluation and mitigation strategy (REMS) to include a medication guide to educate patients about the drug's risks was also developed.

HSA's advisory

In the light of this safety issue, healthcare professionals are advised not to start new patients on Raptiva®. Those patients currently taking the drug should however, not have their therapy discontinued abruptly. Instead, healthcare professionals are advised to review the treatment of patients currently taking this drug to assess the most appropriate alternatives as soon as possible.

They should also monitor their patients who have been treated with Raptiva® closely for neurological symptoms and symptoms of infection. The effects of Raptiva® on the immune system may last for about eight to 12 weeks.

References

1. EMEA Press Release. http://www.ema.europa.eu/ema/index.jsp?curl=pages/news_and_events/news/2009/11/news_detail_000207.jsp&mid=WC0b01ac058004d5c1 ↗ (opens in new tab)

2. EMEA Questions and Answers on Raptiva®.  http://www.ema.europa.eu/docs/en_GB/document_library/Medicine_QA/2009/11/WC500014492.pdf ↗ (opens in new tab)

3. Health Canada's healthcare professional communication. http://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2009/14571a-eng.php ↗ (opens in new tab)