Drug Safety

A mother recently brought her young daughter to see me for treatment of scalp psoriasis. I recommended they use a topical corticosteroid. The mom was scared of putting the medication on her child and would have preferred some type of dietary or “natural” product as a treatment instead. It seemed she was hoping for some magical intervention that would clear the problem without the potential for side effects. Having a well characterized chemical entity whose benefits and risks are well characterized seems a lot safer to me. A “natural” product could contain dozens (if not hundreds) of potentially active substances, not to mention the possibility of being adulterated with real drugs.

One of the downsides of knowing the safety profile of drugs is the potential for patients to be scared off by rare risks. This is a problem for governmental regulatory agencies as well. Regulators have the responsibility of making sure that the benefit of marketed drugs exceeds their risks. My bias is that the regulators should let drugs pass as much as is reasonably possible, giving doctors and patients the opportunity to decide whether the benefit exceeds the risk in each particular patient's situation.

There have been four reports of progressive multifocal leukoencephalopathy (PML) in patients taking efalizumab (Raptiva). On February 19, 2009, the European Medicines Agency (EMEA) recommended the suspension of the marketing of the drug. The EMEA's Committee for Medicinal Products for Human Use (CHMP) concluded that the benefits of efalizumab no longer appear to outweigh its risks. PML is a serious concern. Three of the efalizumab-treated patients with PML died. The full magnitude of the risk of PML associated with efalizumab use may not be fully known.

After reviewing the evidence the CHMP concluded that the benefits of efalizumab are modest, that there are other serious risks besides PML, and that there isn't enough evidence to identify a group of patients in whom the benefits of efalizumab outweigh its risks. The EMEA may be right about this, but I'm not sure. Saying that the benefits of efalizumab are modest may make sense when considering large populations, but some individual patients who are suffering horribly with psoriasis may have benefits from efalizumab treatment that are far more than modest. And while the EMEA may not have good evidence that there's a population of people who need the drug, physicians may have individual patients in whom efalizumab treatment may be the most appropriate option after consideration of all the alternatives.

Drug safety is a critical issue and one that the Journal of Dermatological Treatment hopes to focus on. Extensive, high quality data collection is needed to characterize the risks, especially the rare risks, of the medications we prescribe. Armed with such knowledge, physicians and patients can work together to choose treatments that offer patients the greatest hope of disease control at a minimum of risk.

Acknowledgements

The Center for Dermatology Research is funded by an unrestricted educational grant from Galderma Laboratories, L.P.