Australians ineligible for surgery or radiation for metastatic or locally advanced cutaneous SCC now have access to a monoclonal antibody.
Immunotherapy is now available for Australians with metastatic or locally advanced cutaneous squamous cell carcinoma (CSCC) who are not eligible for curative surgery or radiotherapy.
The TGA provisionally approved cemiplimab (Libtayo, Sanofi) under a fast-track scheme for serious and life-threatening conditions.
“The introduction of [cemiplimab] is a critical breakthrough for a cancer that causes substantial morbidity and mortality, with a median survival of less than 15 months,” said Professor Danny Rischin, director of medical oncology at Peter MacCallum Cancer Centre, in a statement.
Australians have higher rates of cutaneous squamous cell carcinoma than any other population, and prognosis is poor when the cancer is diagnosed late.
This is the first immunotherapy approved in Australia for metastatic or locally advanced CSCC. The monoclonal antibody targets and blocks the programmed death receptor-1 (PD-1) on T-cells, which cancer cells use to reduce T-cell response. Blocking this allows T-cells to remain active, enhancing their immunological effect.
Previously, the only treatments patients with cutaneous squamous cell carcinoma had available were surgery or radiation therapy.
“[Cemiplimab] represents a new standard of care for this aggressive skin cancer that disproportionately impacts Australians,” said Professor Rischin.
Cutaneous squamous cell carcinoma, which may appear as a rough, scaly patch or wart-like lump, accounts for around one in five skin cancers. PBAC is currently evaluating whether to list the drug on the PBS for this indication.
The recommended dose is a 350mg intravenous infusion every three weeks, delivered over 30 minutes. Treatment can continue until the disease progresses or the toxicity becomes unacceptable.
The approval follows promising phase I and II multicentre, open-label and non-randomised clinical trials.
In these studies, patients were treated with either 3mg/kg intravenous cemiplimab every two weeks or 350 mg every three weeks, either for up to 48 weeks or up to 96 weeks.
The objective response rate (ORR) was assessed independently on radiological data or digital medical photography, and medication was continued until either the disease progressed, the toxicity became unacceptable or the patient completed their planned treatment.
Of the 193 patients who had the longest follow up, half responded to treatment, and for one in six, their tumour completely disappeared.
More than 90% of patients responded for more than six months and 12 month survival was more than 80%.
According to the product information, the most common side effects are fatigue (22%), rash (23%), diarrhoea (13%) and pruritis (12%).
“The decision to approve this indication has been made on the basis of objective response rate (ORR) and duration of response from single arm clinical studies. The sponsor is required to submit further clinical data to confirm the clinical benefit of the medicine,” a spokeswoman for Sanofi said.
Professor Rischin has received research grants from Sanofi and has been on an uncompensated scientific committee and advisory board for the manufacturer.
[Edit: This article has been updated with more current study data.]