From September 1, thousands of Australians with advanced or metastatic cancers will gain subsidised access to the immunotherapy drug pembrolizumab, marketed as Keytruda, under an expanded listing on the Pharmaceutical Benefits Scheme (PBS). This pan-tumour listing allows eligible patients with a range of cancers—particularly those whose tumours cannot be surgically removed and are sensitive to immunotherapy—to access the treatment at a significantly reduced cost.

Previously, Keytruda was available on the PBS for specific cancers, but patients with rarer or less common tumour types often faced steep out-of-pocket expenses, sometimes exceeding $14,000 per treatment cycle. Under the new arrangement, concessional patients will pay $7.70 per infusion while general patients pay $25, easing financial pressure for many. It is estimated that approximately 700 patients will benefit annually in the near term, with projections suggesting up to 10,000 patients may become eligible over the next four years.

Health Minister Mark Butler described the expanded PBS listing as a milestone, emphasizing the scheme's role in providing wider access to world-leading medicines at affordable prices. "Keytruda is one of the most extraordinary drugs available in the country and now it is listed to help so many more Australian patients," Butler said. The listing was secured after six months of negotiations with the drug’s manufacturer, MSD.

Keytruda is an immunotherapy that leverages the patient’s own immune system to target cancer cells and has been transformative in treating multiple cancer types. The recent expansion enables treatment across nearly 30 cancer types, including rare forms such as cholangiocarcinoma (bile duct cancer), adrenocortical carcinoma, and Merkel cell carcinoma, as well as chemotherapy-resistant ovarian cancer.

This pan-tumour approach addresses a longstanding limitation in the PBS, which traditionally approves drug listings on a cancer-by-cancer basis. Such a model often excludes patients with rare cancers sharing genetic mutations for which the drug is effective, due to the difficulty of obtaining distinct clinical trial data for each cancer type. Oncologists, including Sumitra Ananda from the Peter MacCallum Cancer Centre and Epworth HealthCare, have welcomed the change, noting it allows physicians greater discretion to make evidence-based treatment decisions.

The new PBS listing follows years of advocacy from patient groups and underscores growing efforts to adapt Australia's medicines funding system to advances in genomic medicine and cancer therapies. Patients like Celestino Carosella, who previously paid tens of thousands of dollars out-of-pocket for Keytruda to treat a rare adrenal gland cancer, have expressed relief. Carosella’s tumours have since regressed, highlighting the potential life-changing impact of broader access.

MSD Australia & New Zealand managing director Chifumi Umeda acknowledged the reform as a critical step forward for cancer treatment funding in collaboration with the federal government. As of September 1, eligible Australian patients across a wide spectrum of cancers will be able to access pembrolizumab under this landmark PBS listing.