Two breakthrough psoriasis drugs have been listed on the PBS.

One new medicine for chronic plaque psoriasis - Tremfya (guselkumab) – would have cost sufferers $30,000 a year to maintain a supply.

But from February 1 its listing on the Pharmaceutical Benefits Scheme will push its price down to $40.30 per script.

Tremfya (guselkumab) is delivered through injections and works by neutralising the activity of a specific protein and reducing proteins in the skin responsible for causing psoriasis plaques.

The second psoriasis treatment listed on the PBS - Ilumya (tildrakizumab) - fights psoriasis by reducing inflammation and other symptoms.

Its current cost of about $32,000 per year will also drop to $40.30 a script, with about 10 scripts per year required on average.

Thousands of people are expected to benefit from the two PBS listings, which had been recommended by the Pharmaceutical Benefits Advisory Committee.