Breast cancer is the most common cancer among women globally. Every 15 seconds, one woman is diagnosed with breast cancer somewhere in the world.
It is the most common form of malignancy affecting women. In Malaysia, breast cancer affects 32.1% of all female cancer patients.
The over-expression of the Human Epidermal Growth Factor Receptor 2 (HER2) in this cancer is associated with poor prognosis, i.e. shorter time to relapse after treatment and shorter overall survival in patients.
Studies show that 23%-28% of patients diagnosed with breast cancer are HER2-positive in Malaysia.
“HER2-positive early breast cancer is an aggressive disease, and additional risk factors, such as lymph node involvement, will lead certain patients to experience disease recurrence even earlier.
“Despite adjuvant treatment with trastuzumab, approximately one in four HER2-positive early breast cancer patients experience a relapse of their disease in the long-term,” said consultant clinical oncologist Dr Matin Mellor.
Consultant breast and breast reconstructive surgeon Dr Ng Char Hong added: “The only setting where HER2-positive breast cancer can potentially be cured is at the early stage.
“There is no cure for breast cancer that recurs and reaches an advanced stage where treatment is solely aimed at prolonging life for as long as possible.
“Thus, it is clinically meaningful to effectively treat breast cancer patients at the earliest stage.”
Both doctors were speaking at the launch of Perjeta® (pertuzumab), which has been approved for use in combination with Herceptin® (trastuzumab) and chemotherapy, for the adjuvant treatment (post-surgery) of patients with HER2-positive early breast cancer at high risk of recurrence.
Previously, this combination was approved for the treatment of metastatic HER2-positive breast cancer (without surgery), where it was shown to significantly extend survival compared to Herceptin and chemotherapy alone.
Now, with the adjuvant approval, it means that eligible patients with HER2-positive early breast cancer in Malaysia can be treated with the Perjeta/Herceptin combination for a period of one year after they have had surgery to remove their breast cancer.
Perjeta targets the HER2 receptor, a protein found on the surface of many normal cells and in high quantities on the surface of cancer cells in HER2-positive cancers.
It is designed specifically to prevent the HER2 receptor from pairing (or dimerising) with other HER receptors (EGFR/HER1, HER3 and HER4) on the surface of cells.
The mechanisms of action of Perjeta and Herceptin are believed to complement each other. Both bind to the HER2 receptor, but at different places.
The combination is thought to provide a more comprehensive, dual blockade of HER signalling pathways, thus preventing tumour cell growth and survival.
A phase 3 clinical trial called Aphinity, involving over 4,800 people with HER2-positive early breast cancer was conducted, comparing the use of Perjeta, Herceptin and chemotherapy after breast cancer surgery, with the use of Herceptin and chemotherapy alone.
The results showed that the triple combination reduced the risk of invasive breast cancer recurrence or death, compared to the dual combination in the overall study population.
The greatest benefit was observed in patients with lymph node-positive or hormone receptor-negative breast cancer, with the risk of recurrence or death decreased by 23%.
Among patients with hormone receptor-negative disease, the triple combination reduced the risk of recurrence or death by 24%.
In terms of safety, the triple combination is as safe to use after surgery as without surgery, with a low incidence of primary cardiac events (<1%) and no new safety issued noted.
Managing director of Roche (Malaysia) Sdn Bhd, which produces both Perjeta and Herceptin, Lance Duan said: “Roche’s treatment goal for early breast cancer is to cure the disease.
“While treatment outcomes have improved over the years, unfortunately, some patients still have recurrence of breast cancer.
“As such, today’s launch of the Perjeta/Herceptin combination as an adjuvant treatment is highly significant.
“There is another option that can make an even greater contribution to the advancement of breast cancer treatments.”
This combination treatment is included in Roche’s Patient Assistance Programme, which helps eligible patients access the Roche medicines they are prescribed by providing subsidies to reduce their overall treatment cost.
It is also approved in over 70 countries as adjuvant therapy for HER2-positive early breast cancer, including in the United States, Europe, Japan, Canada, Singapore, Thailand and the Philippines.