New treatment approved for plaque psoriasis

Patients with moderate to severe plaque psoriasis now have access to a new injectable biologic, guselkumab (Tremfya)

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Patients with moderate to severe plaque psoriasis now have access to a new injectable biologic, guselkumab (Tremfya). 

Adults with moderate to severe plaque psoriasis who are candidates for systemic therapy or phototherapy are now eligible for the drug, thanks to a new TGA listing. 

Past president of the Australasian College of Dermatologists, Professor Stephen Shumack, said he was looking forward to its availability on the PBS, after early use in countries such as the US indicated the drug was “as effective, if not more” effective than current treatments, with a good safety profile. 

“They provide another option as far as the treatment is concerned, particularly for patients where their current biological agent might not be working very well.” 

Guselkumab is the first in a new class of drugs that selectively blocks the cytokine interleukin (IL)-23, which is critical for the protein-driven formation of plaque. 

“Psoriasis is a systemic immune disease; patients typically have multiple co-morbidities, and the prescribing protocol is complex,” Associate Professor Peter Foley, a clinical dermatologist and Director of Research at the Skin & Cancer Foundation Inc, said.

“This means moderate to severe plaque psoriasis may be less than optimally treated.” 

Given the lack of cure for the condition, there was a “significant unmet medical need” remaining, Professor Foley said. 

Patients starting the new treatment receive the first subcutaneous injection after being cleared of tuberculosis. 

The second injection follows at four weeks, and then the following injections every eight weeks for as long as it is effective. 

While patients are able to do their own injections from home, Professor Shumack said he had a number of patients who chose to visit their GP for injections of their biologics. 

In three large, randomised, double blind trials patients were assessed as having at least moderately severe disease (PASI score >12) and at least 10% of their body surface area affected.

Studies indicated the drug was more effective than adalimumab at resolving plaques over time. More patients reported their psoriasis having little or no impact on their lives after taking guselkumab compared to adalimumab (60% vs 40%) after taking it for a year, according to the manufacturer Janssen. 

In one study, guselkumab gave more than 80% of patients clear, or almost clear, skin after three doses. 

Because the monoclonal antibody is immunosuppressive, side effects typically included infections.

The most adverse events found in studies included injection site reactions, diarrhoea, upper respiratory infections, gastroenteritis, herpes simplex infections, tinea infections, arthralgia and headache.

Patients who have a serious hypersensitivity to guselkumab or any of the excipients should not be offered the medication. 

Clinicians should also test for tuberculosis and treat it before starting patients on the drug, however there are no specific blood indices which need monitoring during treatment. 

Live vaccines are contraindicated while on guselkumab.