The trastuzumab biosimilar Kanjinti has been listed on the PBS from 1 December 2019 as an alternative to the originator brand Herceptin for treatment of breast and gastric cancers.

Kanjinti becomes the fourth brand of trastuzumab listed on the PBS, after Herceptin  (listed in October 2006) , Ogivri (August 2019) and Herzuma (November 2019).

PBS listed indications for trastuzumab include early and metastatic (Stage IV) HER2 positive breast cancer and metastatic (Stage IV) HER2 positive adenocarcinoma of the stomach or gastro-oesophageal junction.

According to the PBS, all three biosimilars have been assessed by the Therapeutic Goods Administration using comparability and clinical studies to be highly similar to Herceptin.

“This means Herzuma, Kanjinti, Ogivri and Herceptin provide the same health outcomes and are as safe and effective as each other,” it says.

The government says it encourages biosimilar substitution of trastuzumab in an effort to reduce pressure on the PBS budget, with cost to government for trastuzumab in 2018-19 being $163.8 million.

“The choice of brand generally used in a hospital or clinic may be based on medicine purchasing decisions made by a clinician-led committee. Specific patient requirements will remain for discussion between a patient and treating clinician,” it says.

However the PBS emphasises that the biosimilars are not substitutable for the subcutaneous formulation Herceptin SC.

Since 1 October 2019, all brands of trastuzumab have been listed on the PBS with a requirement that the prescriber obtain Authority Required (STREAMLINED) approval. Further listing changes from 1 October 2019 allow adjuvant or neo-adjuvant treatment for early breast cancer, and treatment in combination with any platinum chemotherapy for advanced gastric cancer.