Clinuvel Pharma's afamelanotide shows positive effect in vitiligo repigmentation study but skin darkening effect dampens recruitment.

Synthetic afamelanotide, produced by Clinuvel, is a simplified form of a natural alpha-melanocyte stimulating hormone (a-MSH). It stimulates melanocytes to regrow and produce more pigment. The drug has been earlier approved in Europe for the treatment of porphyria, a disease characterized with extreme sensitivity to sunlight.

A Phase 2 clinical trial evaluating Aussie drugmaker Clinuvel Pharmaceuticals' SCENESSE (afamelanotide) in Asian patients with vitiligo is underway. This new medical treatment showed a positive effect in restoring pigmentation in combination with UVB therapy. However, excessive skin darkening - both on white patches and on normal skin - prompted the withdrawal of three participants out of 21. This undesired side effect is often a concern for vitiligo patients because it makes white spots more obvious before they get better, and it has hampered recruitment.

The company is assessing its options for future labeling, possibly refining suitable patients to those with a loss of pigmentation of at least 10% of their body surface area. Patients with more modest disease that affects less than 2% of their body surface area, may prefer topical or traditional UVB therapy.

Source: Seeking Alpha

RECAP: It is well-known that UVB treatment for vitiligo is time-consuming, requiring 12-18 months of twice-weekly sessions, before a near-complete repigmentation is achieved in the majority of the patients. So a drug like Scenesse that speeds up and improves the process was seen as an opportunity to eliminate white spots and repigment skin faster. However, it didn't quite live up to expectations. 

In the earlier US trials, vitiligo patients were treated with afamelanotide plus nbUVB. They were receiving a grain-size implant, just above their hip, that contained 16 mg of afamelanotide, every three months. The drug slowly diffused out into the body, providing a stimulus for all melanocytes in the skin. The pigment came back on average 20 days sooner with the afamelanotide, compared to those who received placebo plus nbUVB, and more pigment returned as well. It worked better for those with darker skin type, Fitzpatrick IV and up. Patients with lighter skin types often complained about excessive skin darkening, especially in the areas surronding white patches. Other side-effects include nausea and fatique. A reportedly high cost of the procedure - over $20,000 - does not make it a preferable treatment option for uninsured patients.