Over The Horizon

Psoriasis Vaccine Under Testing

New Zealand biotechnology company Genesis Research and Development has discovered a promising treatment for the previously incurable skin disease psoriasis. Genesis, together with US partner Corixa Corporation, has developed a likely treatment for psoriasis from Mycobacterium vaccae. The vaccine, PVAC, is currently entering phase II clinical trials in the Philippines.

"About three percent of the world's people suffer from psoriasis, and we're confident we've found a cure," says Genesis CEO Dr Jim Watson. "We've secured the patent for PVAC and our clinical trial is yielding results which can only be described as dramatic."

Psoriasis affects an estimated 100 million people worldwide. Main symptoms of the disease are chronic inflammatory skin lesions with red, scaling plaques. About a third of patients are so severely affected that they may have difficulty holding jobs. They need expensive and harsh treatments, which often have severe side effects and long-term system toxicity. Also, benefits last only as long as the treatment continues; lesions return shortly after the treatment stops.

Immunologists understood very little about this relatively common disease until the early 1990s. Physicians testing M. vaccae as a leprosy treatment noticed that those patients with psoriasis had dramatic clearing of their symptoms. At the same time Genesis researchers were identifying M. vaccae proteins for possible vaccine use against tuberculosis and leprosy, and from this they developed PVAC for psoriasis.

The company worked on vaccine therapies for a variety of diseases for five years before developing PVAC. Using a vaccine as a curative rather than a preventative is novel; vaccines are usually introduced to teach the body how to fight against an attacking disease it has not yet met. With PVAC, the vaccine teaches the body to fight an autoimmune disease (one that makes the body fight itself) that is already present.

Genesis is now supporting PVAC trials at renowned skin disease research centre, the Leonard Wood Memorial Skin Clinic, in Cebu, the Philippines.

The psoriasis lesions, visible in the image above as white patches, respond to the vaccine treatment.

The same patient 63 days after the vaccine was administered.