Trastuzumab Biosimilars — Canmab, Hertraz and Herceptin in India

CDSCO biosimilar approval requires the manufacturer to show the product is highly similar to the reference medicine — the same HER2 target, the same mechanism, and no clinically meaningful difference in how it works. Neither biosimilar is permitted to claim superiority, and the regulator does not approve one that falls short of the reference standard. Oncologists and hospitals treat CDSCO-approved biosimilars as therapeutically equivalent to the originator for the approved indications. The specific product used in your treatment is chosen by your oncologist and treating centre based on availability, institutional formulary and your health cover — not on a judgement that one product works better than another.

The originator company spent many years and very large resources developing, proving and obtaining approval for trastuzumab. Those costs are reflected in the originator's price. A biosimilar manufacturer demonstrates similarity to the already-proven reference product and is not required to repeat the original clinical trials from scratch. That abbreviates the development cost significantly, and the savings pass through to price. In India, Canmab and Hertraz were manufactured locally, which reduced production costs further. The difference in price does not reflect a difference in quality or in how the medicine works.

Switching between CDSCO-approved biosimilars and the originator during a course of treatment is not prohibited by Indian guidance, and it is accepted practice in several other regulatory systems. However, switching is a clinical decision — it should happen with your oncologist's knowledge and agreement, not on your own initiative because of a cost pressure or an availability change. If cost is a concern, tell your oncologist directly. There may be a formulary substitution, a scheme listing, or an institutional supply arrangement that addresses it without requiring an unplanned switch mid-course.

Coverage depends on the specific scheme. Government programmes such as PM-JAY and some state health schemes list trastuzumab as part of approved cancer protocols and may specify the biosimilar formulation. Private insurance policies vary; some have sub-limits on biological medicines or on cancer treatment overall, and employer group schemes also differ. The hospital billing team at your treating centre is usually the fastest way to find out which version of trastuzumab is covered under your specific policy, and what prior authorisation may be required before the first cycle.

The most important effect to monitor is cardiac. Trastuzumab can reduce the left ventricular ejection fraction — a measure of how well the heart pumps — and this is tracked with periodic echocardiograms during treatment. Tell your team promptly about breathlessness, new swelling in the legs, or a rapid or irregular heartbeat, because these may indicate a cardiac change that needs assessment. Infusion reactions including fever, chills and breathlessness can occur during the first infusion and are managed at the time. Most people tolerate subsequent cycles without significant infusion reactions once the first one is completed.

In early HER2-positive breast cancer, ASCO and NCCN guidance recommends approximately twelve months of adjuvant trastuzumab following surgery and chemotherapy. In the neoadjuvant setting — given before surgery — the duration is part of the broader treatment plan. In metastatic disease, treatment continues for as long as it is working and tolerated, and is reviewed regularly with your oncologist. The planned duration is the same whether you receive the originator or a biosimilar. Your oncologist will explain the length based on your specific stage and whether the aim is adjuvant, neoadjuvant, or metastatic treatment.