Australians with advanced or metastatic gastro-oesophageal cancers and those fighting advanced bladder cancer will now have cheaper access to treatments through the Pharmaceutical Benefits Scheme.

The federal government has expanded the PBS listing of gastro-oesophageal cancer drug nivolumab, which could help up to 1450 patients each year.

A bladder cancer maintenance therapy Bavencio has also been added to the scheme from Saturday.

Without subsidy, a course of nivolumab could cost more than $92,000 but that will now be cut to $42.50 for each script, or $6.80 for those on concessions.

The same cheaper prices will apply to Bavencio.

Health Minister Mark Butler said there was a high clinical need for effective treatments for gastro-oesophageal cancers, with only one in five sufferers surviving five or more years after diagnosis.

"The expanded listing is vitally important. It will provide affordable treatment that will improve the lives of patients with gastro-oesophageal cancers," he said.

The PBS listing for Bavencio is for patients with advanced or metastatic urothelial carcinoma where the disease is still present but has not progressed after initial chemotherapy.

It aims to delay or prevent the cancer from growing again by stimulating the immune system as soon as the patient completes chemotherapy treatment.

Bladder Cancer Australia board member and cancer survivor Tony Moore said the government was to be applauded for subsidising the treatment.

"Too many Australians lose their lives to bladder cancer," he said.

About 600 Australians will be eligible to receive the treatment.