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AstraZeneca Pharma India Ltd has received approval from India's drug regulator to import, market, and distribute its targeted cancer therapy Enhertu for an additional indication, marking a significant development in the treatment of advanced HER2-positive breast cancer in the country.
The approval was granted by the Central Drugs Standard Control Organisation (CDSCO) on June 10. With this clearance, Enhertu (trastuzumab deruxtecan 100 mg/5 mL), in combination with pertuzumab, can now be used as a first-line treatment for adult patients with unresectable or metastatic HER2-positive breast cancer.
The decision expands treatment options for a group of breast cancer patients who often require highly targeted therapies to improve outcomes and control disease progression.
Understanding HER2-positive breast cancer
Breast cancer is not a single disease but consists of several subtypes. One of these is HER2-positive breast cancer, where cancer cells produce excessive amounts of the HER2 protein, causing tumours to grow and spread more aggressively.
Dr Jay Anam, Breast Cancer Surgeon and Oncoplasty Specialist, explained that around 15-20 per cent of breast cancer patients are diagnosed with HER2-positive disease.
"Traditional chemotherapy can be compared to a machine gun because it attacks both cancerous and healthy cells, leading to side effects. HER2-targeted therapies work more like a sniper, identifying and attacking only those cancer cells that carry the HER2 receptor," told The Free Press Journal.
According to him, targeted therapies have become an essential component of treatment for eligible patients because they significantly reduce the chances of cancer returning and help control metastatic disease more effectively.
Not a new drug
Doctors point out that while the recent CDSCO approval is for a new indication, trastuzumab-based HER2-targeted therapies have been part of breast cancer treatment for many years.
"This is not a new concept in cancer treatment. HER2-targeted therapy is now a time-tested and proven approach that has been used for well over a decade. We know from long-term evidence that when these drugs are incorporated into treatment, the chances of cancer returning are significantly lower," Dr Anam said.
He added that the drugs are equally important for patients whose cancer has spread beyond the breast, as they help control metastatic disease and improve outcomes.
However, he stressed that the therapy is not meant for all breast cancer patients.
"We only recommend it when biopsy results confirm HER2 positivity. If the tumour does not show HER2 positivity, this treatment will not provide benefit," he said.
What makes ENHERTU different?
Enhertu belongs to a newer class of medicines known as antibody-drug conjugates (ADCs), often referred to as "smart chemotherapy".
Dr Adwaita Gore, Senior Medical Oncologist at SL Raheja Hospital, Mumbai, said the drug combines the precision of targeted therapy with the cancer-killing power of chemotherapy.
"It is engineered to deliver chemotherapy directly into HER2-positive cancer cells. In simple terms, it uses the HER2 marker as an address label to carry the treatment exactly where it is needed," he explained.
Unlike older HER2-targeted therapies that mainly benefited patients with very high HER2 expression, Enhertu has shown effectiveness across a broader spectrum of patients, including some with lower HER2 expression levels.
"It is not just helping patients with HER2 3+ disease. Clinical data have shown responses even in HER2-low categories, which has expanded treatment possibilities," Dr Gore noted.
Benefits extend beyond traditional HER2 patients
One of the most significant advantages of Enhertu, according to oncologists, is its ability to help a broader group of patients.
Historically, anti-HER2 therapies were mainly reserved for patients with strong HER2 expression, typically classified as HER2 3+, or those testing positive through FISH analysis.
However, Dr Gore noted that clinical studies have shown responses even in patients with lower HER2 expression.
"HER2 expression is generally classified as 0, 1+, 2+, and 3+. Earlier anti-HER2 therapies were largely useful for HER2 3+ patients. Enhertu has demonstrated benefits not only in 3+ patients but also in HER2-low categories such as 1+ and 2+. That expands the spectrum of patients who may potentially benefit from targeted treatment," he said.
A proven therapy with growing clinical use
While the recent approval relates to a new indication, HER2-targeted treatment itself is not new.
Dr Anam pointed out that trastuzumab-based therapies have been used globally for many years and have transformed outcomes for HER2-positive breast cancer patients.
"This is a time-tested treatment approach. We know from long-term evidence that when these therapies are used appropriately, recurrence rates are lower and disease control is better," he said.
The therapy is recommended only for patients whose biopsy reports confirm HER2 positivity and is not suitable for all breast cancer cases.
Improved outcomes, but cost remains a challenge
Doctors agree that Enhertu has delivered impressive clinical results compared to previous treatment options.
Dr Gore said studies have demonstrated an additional 30-35 per cent benefit over earlier standard therapies used for HER2-positive breast cancer.
"It improves survival and disease control compared with previously available treatments," he said.
However, he cautioned that patients receiving Enhertu require close monitoring because the drug can sometimes cause interstitial lung disease, a serious lung-related side effect.
The biggest hurdle, according to oncologists, remains affordability.
Dr Gore estimated that a single treatment cycle can cost around Rs 3.5 lakh, depending on a patient's body weight, as dosing is calculated per kilogram.
"Even if I prescribe this medicine to 100 patients, fewer than 10 per cent are ultimately able to take it because of the cost," he said.
Dr Anam noted that HER2-targeted therapies were once even more expensive.
"When trastuzumab-based treatment was first introduced, costs were around Rs 2 lakh per dose. Over time, after patent expiry and the introduction of generic alternatives, treatment costs reduced significantly. Some patients can now access certain HER2-targeted therapies at much lower rates depending on the brand and support programmes available," she said.
He added that cost remains an important consideration because HER2-targeted treatment often continues for a year or longer.
"Once treatment starts, many patients need to continue it for about a year. That's why affordability becomes a very important factor in treatment planning," Dr Anam said.
Insurance and access remain key concerns
Despite the drug's clinical success, doctors say only a small percentage of eligible patients are currently able to access it.
Dr Anam noted that the cost of HER2-targeted therapies has reduced over the years as generic alternatives entered the market, making treatment more accessible for some patients. However, affordability continues to be a major factor because treatment often extends for a year or longer.
Dr Gore echoed similar concerns, saying that while the approval will benefit patients clinically, access remains limited for many families.
"Even when I prescribe the drug to 100 patients, fewer than 10 per cent ultimately proceed with treatment because of the financial burden," Dr Gore said.
He also raised concerns about insurance reimbursement.
"Many insurance companies still refuse coverage for newer therapies by categorising them as modern medicines," he said.
He further added, "Only patients with strong insurance coverage or the ability to pay out of pocket are currently able to access these newer therapies. Wider patient-support programmes and better reimbursement mechanisms will be critical if more patients are to benefit from these advances".
According to Dr Gore, while AstraZeneca has introduced patient-support programmes aimed at reducing overall treatment costs, wider access will require stronger support from insurers and healthcare systems.
With breast cancer remaining one of the most common cancers among women, oncologists say the approval of Enhertu for first-line treatment adds another important weapon to the fight against HER2-positive disease, offering new hope for patients facing advanced stages of the illness.
