What is HER2-positive breast cancer, for which Goa is offering free treatment worth ₹4.2 lakh per patient?

Alarming statistics from the World Health Organisation (WHO) reveal that 98,337 women succumbed to breast cancer in India, with 1,92,020 reported cases.

However, the survival of these women hinges on exorbitantly priced drugs prevalent in the Indian market.

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What is HER2?

HER2-positive breast cancer denotes a subtype characterised by the overexpression or amplification of a protein known as HER2 (human epidermal growth factor receptor 2). HER2, a receptor influencing cell growth and division, becomes problematic when overexpressed or amplified in cancer cells, leading to uncontrolled and aggressive growth.

Let’s envision our bodies as sprawling cities with numerous buildings representing cells. Each cell follows a set of instructions (genes) dictating its behaviour, growth, and cessation. However, glitches, like broken instructions causing accelerated and unchecked growth, can occur.

HER2-positive breast cancer mirrors such an anomaly in the buildings (cells) of the breast. Here, a specific instruction named HER2 propels excessive cell growth akin to a surge of construction workers causing buildings to sprout rapidly.

Doctors use special tests to find out if someone’s breast cells have too much HER2. If they do, it’s called HER2-positive breast cancer. But the good news is that scientists have found a way to stop those extra instructions from causing trouble.

Here’s where medical superheroes, Trastuzumab and Pertuzumab, come into play. These agents adeptly halt HER2’s extra instructions, preventing cells from growing uncontrollably. They collaborate with doctors and other medications to rectify the issue, ensuring the buildings (cells) don’t spiral out of control.

Speaking to South First, Dr Nitin Yashas, Consultant-Medical Oncologist and Hemato-Oncologist at Manipal Hospital in Bengaluru, said, “HER2 is a protein expressed by the cancer cells which makes it aggressive. It can be found in 20-30 percent of breast cancer patients. Trastuzumab is a medicine that blocks this pathway and has now been in use for many years and is the standard of care for treatment of HER2-positive breast cancer, along with chemotherapy. With the availability of bioequivalent generics, the accessibility to this standard has increased over the years.”

Adding to this, Dr L Rohit Reddy, Consultant Medical Oncologist & Hemato-Oncologist, Yashoda Hospitals in Hyderabad, said, “The presence of HER2 overexpression is identified through specific tests, such as immunohistochemistry (IHC) or fluorescence in situ hybridisation (FISH), which are performed on a biopsy sample of the breast tumour.”

He added that HER2-positive breast cancer tends to be more aggressive than HER2-negative breast cancer, and it may have a higher likelihood of spreading (metastasising) to other parts of the body. However, the good news is that targeted therapies, such as the monoclonal antibodies Trastuzumab (brand name: Herceptin) and Pertuzumab (brand name: Perjeta), have been developed to specifically target HER2-positive breast cancer.

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Inflated cost of Pertuzumab-Trastuzumab

The steep cost of medications like Pertuzumab and Trastuzumab can be attributed to extensive research and development (R&D) expenses. Pharmaceutical companies invest significantly in discovering, testing, and bringing innovative treatments to market.

Clinical trials, an indispensable part of the drug approval process, contribute to the high costs. Before a drug is approved for use, it must undergo extensive clinical trials to ensure its safety and effectiveness. Conducting these trials is an expensive and time-consuming process.

Biologic drugs, such as monoclonal antibodies like Pertuzumab and Trastuzumab, are more complex to manufacture than traditional chemical-based drugs, adding to production expenses.

Limited market size is a significant factor; drugs targeting specific conditions may have a smaller patient population, leading to higher individual costs. Moreover, pharmaceutical companies often enjoy exclusive patent protection for new drugs, allowing them to set higher prices initially.

Despite the hefty price tag, Pertuzumab-Trastuzumab proves to be an effective treatment for HER2-positive breast cancer.

Dr Yashas highlighted, “By the addition of Pertuzumab, we are able to achieve a dual HER2 blockade leading to better response, better shrinkage of tumour, and better survival. When we give this combination along with chemotherapy for typically six cycles before surgery and then operate, there is excellent reduction of the tumour. In 60-70 percent of the cases, the final pathology reports show no evidence of cancer cells. We now have the Trastuzumab-Pertuzumab combination available as a single injection which can be given into the skin over 10 minutes at three-weekly intervals. This combination is also used in stage 4 HER2 positive breast cancer patients.”

“It is heartening to see the Goa government make it available free of cost, which is no doubt going to help numerous breast cancer patients. Hopefully, other states will follow through,” added Dr Yashas.

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Landscape of essential cancer medicines

Several essential drugs for breast cancer, costing approximately ₹6-12 lakh annually, extend life by 12 months. Abemaciclib, used for treating certain cancers, including advanced breast cancer, is priced at around ₹20,000 per box.

The cost of Palbociclib, a CDK4/6 inhibitor, has significantly decreased in India due to generic versions entering the market. Previously priced at ₹95,000 per month, it’s now available at a fraction of the cost, making treatment more affordable.

Ribociclib, available as Kryxana in India, costs approximately ₹58,140 per month, with the 200 mg tablets priced at around ₹20,081 per box.