The Australian government has expanded access to ribociclib (Kisqali), a CDK4/6 inhibitor, through the Pharmaceutical Benefits Scheme (PBS) effective July 1, making this potentially life-saving treatment available to early-stage breast cancer patients at a fraction of its previous cost. The drug, which previously cost patients $3,700-$4,000 per month without subsidy, is now accessible to women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) early breast cancer who are at high risk of recurrence due to lymph node involvement.
Clinical Evidence Supporting PBS Listing
The PBS expansion is supported by results from the global NATALEE trial, published in The New England Journal of Medicine. This multi-center randomized trial involved 5,101 patients with HR+/HER2- early breast cancer, who were randomly assigned to receive either ribociclib plus hormone therapy or hormone therapy alone for three years. The study demonstrated that adding ribociclib to standard endocrine therapy reduced recurrence risk by 28.5% compared with hormone therapy alone.
The trial specifically targeted patients with the most common breast cancer subtype, which accounts for 70-80% of all breast cancer cases. Dr. Belinda Yeo, an oncologist at Austin Health and Olivia Newton-John Cancer Research Institute, described these as the "garden varieties" of breast cancer, affecting approximately 70% of early breast cancer patients.
Mechanism of Action and Patient Population
Ribociclib belongs to a class of drugs known as CDK4/6 inhibitors, which target proteins involved in cancer cell division, effectively slowing or stopping cancer cells from dividing. The drug is specifically indicated for women in the initial stages of early breast cancer who are deemed at high risk of recurrence because their cancer involves lymph nodes.
Dr. Sally Baron-Hay, an Australian NATALEE phase two study investigator, noted that while the listing provides another treatment option for early breast cancer patients with high-risk cancer involving multiple lymph nodes, not all patients at high risk would be eligible under current criteria.
Economic Impact and Patient Access
The PBS listing represents a significant cost reduction for patients, who previously faced treatment costs exceeding $140,000 for a complete course of therapy. Without subsidy, patients were paying approximately $3,700-$4,000 monthly for three years, with some resorting to crowdfunding to access the medication.
Catherine McLardy, a 38-year-old primary school teacher diagnosed with stage three breast cancer, exemplifies the patient population benefiting from this expansion. After discovering an eight-centimeter mass beneath her nipple, she underwent 16 rounds of chemotherapy, 25 doses of radiation, and mastectomy. McLardy received compassionate access to the drug during her treatment and described getting access to ribociclib as "hitting the jackpot."
Disease Burden and Clinical Context
Breast cancer remains the most common cancer among women in Australia, with approximately 58 people diagnosed daily and nine deaths occurring from the disease each day. Around 21,000 people, predominantly women, were diagnosed with breast cancer in 2024. Notably, around 20% of all breast cancer diagnoses occur in women under 50, with an observed increase in young people being diagnosed with the disease.
Federal Health Minister Mark Butler emphasized that the PBS expansion aligns with the scheme's core mission of providing "access to the best available treatment at affordable PBS prices." Kirsten Pilatti, CEO of Breast Cancer Network Australia, which accepts no funding from pharmaceutical companies, supported the PBS listing, highlighting its importance for reducing recurrence risk in early-stage patients.
Clinical Perspective on Treatment Options
Dr. Yeo noted that the PBS listing would broaden treatment options for patients intended to be cured, describing the challenge of early breast cancer treatment as determining "when and to whom" cancer would return. She emphasized that "in the Goldilocks zone of trying to get the right treatment for the right patients, the more options the better."
The expansion addresses a critical gap in treatment access, as patients with non-metastatic breast cancer previously could not access ribociclib without significant out-of-pocket expenses. This development is particularly significant given that recurrence risk in early-stage breast cancer "is not necessarily different from year two or three to year five or six," according to Dr. Yeo, highlighting the long-term nature of recurrence risk in this patient population.
