Eflornithine hydrochloride

Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.

Vaniqa (Epitan)
11.5% cream in 30 g tubes
Approved indication: facial hair
Australian Medicines Handbook section 8.10

Eflornithine is an inhibitor of ornithine decarboxylase, an enzyme involved in cell proliferation and function. It was first studied in oncology, but was found to be active in trypanosomiasis. The drug's effectiveness in treating African sleeping sickness led to it being called 'the resurrection drug'.¹

Unfortunately, parenteral eflornithine was too expensive for the countries that needed it. Commercial considerations therefore resulted in the manufacturer ceasing production in 1995.¹

During treatment of trypanosomiasis it was noticed that some patients lost their hair. This led to the development of a topical formulation for slowing hair growth, opening up a more lucrative cosmetic market.¹ The Australian indication is for delaying the regrowth of unwanted facial hair, following depilation, in women.

The main clinical trials of eflornithine enrolled women who usually removed their facial hair at least twice a week. Compared to the 201 women randomised to apply the vehicle, the 393 who applied eflornithine twice daily had less hair growth. In the opinion of the treating doctors, after 24 weeks of treatment 32% of the women using eflornithine showed a marked improvement compared with 8% of those applying the vehicle. Secondary endpoints such as feeling 'uncomfortable at social gatherings' or 'uncomfortable in exchanges of affection' all showed that women given eflornithine no longer felt as bothered about facial hair as the women who had used the vehicle. The differences between the groups disappeared after treatment ceased.

Only a few of the women in the trials had polycystic ovary syndrome. Women who were using other treatments for hirsutism were excluded from the trials and published comparative studies are lacking.

Although a small proportion of the dose is absorbed into the systemic circulation, mainly local adverse reactions were reported during the trials. These included burning, stinging, itching, redness and tingling of the skin. Acne was reported in 21% of women using eflornithine or the vehicle and approximately 16% of both groups developed pseudofolliculitis barbae. The effects of long-term continuous use of eflornithine are unknown. Its safety in pregnancy has not been established, and it is contraindicated in severe renal impairment.

While women in developed countries can now access eflornithine to try to improve their appearance, access to eflornithine for sleeping sickness is less certain. Although the manufacturers reached an agreement with the World Health Organization to supply the drug, future production may not be assured.

manufacturer provided some data

The Transparency Score () is explained in New drugs: transparency', Vol 37 No 1, Aust Prescr 2014;37:27.

Note on references

At the time the comment was prepared, a scientific discussion about this drug was available on the website of the European Agency for the Evaluation of Medicinal Products (www.emea.eu.int).