Sourcing Monoclonal Antibodies: Where to Buy Genuine Trastuzumab and Rituximab

Rituximab and trastuzumab are two important oncology medicines. Rituximab is used to treat B-cell neoplasms like chronic lymphocytic leukaemia and autoimmune disorders such as rheumatoid arthritis. Trastuzumab is used to target HER2-positive breast and gastric cancers. Their success in improving survival rates has made them popular in cancer treatment protocols worldwide, including in India.

Prof. Dr. Suresh H. Advani, Padma Bhushan awardee, former Chief of Medical Oncology at Tata Memorial Hospital for nearly three decades, and a pioneer of biological therapeutics in India who now works specifically with targeted biological agents including monoclonal antibodies, represents the clinical standard that sourcing these drugs must meet: only through fully verified, licensed channels with complete documentation, administered under specialist oncology supervision. 

This blog explains who manufactures real trastuzumab and rituximab, how much they cost, how to spot fraudulent medicine, and where to buy them safely in India.

Key Takeaways

What Are Trastuzumab and Rituximab Used For?

They are both monoclonal antibodies, laboratory-produced proteins that mimic the immune system's ability to target specific molecular markers on diseased cells. But they target completely different markers and treat completely different conditions.

Trastuzumab

Trastuzumab targets the HER2 receptor, a protein that, when overexpressed on cancer cells, drives aggressive tumour growth. HER2-positive breast cancer accounts for approximately 20 to 25 per cent of all breast cancers globally. Without HER2-targeted therapy, it carries a significantly worse prognosis than HER2-negative disease. Trastuzumab has transformed outcomes.

Trastuzumab uses include:

• Early-stage HER2-positive breast cancer (adjuvant, after surgery)

• Metastatic HER2-positive breast cancer (first and second line)

• HER2-positive gastric or gastro-oesophageal junction cancer

Rituximab

Rituximab targets CD20, a surface antigen expressed on most B cells, including malignant B cells in lymphoma and leukaemia. By binding to CD20, rituximab triggers the immune system to destroy the marked cells.

Rituximab uses include:

• Non-Hodgkin's lymphoma (diffuse large B-cell, follicular)

• Chronic lymphocytic leukaemia

• Rheumatoid arthritis (in combination with methotrexate)

• Granulomatosis with polyangiitis (Wegener's) and related vasculitides

• Pemphigus vulgaris

What Is the Difference Between Trastuzumab and Rituximab?

What is the difference between trastuzumab and rituximab? They work through the same class of mechanism-targeted monoclonal antibody binding, but their targets, indications, and patient populations are entirely distinct:

What Are the Four Main Types of Monoclonal Antibodies?

The classification is based on their origin and degree of humanisation:

Rituximab (a chimeric antibody) and trastuzumab (a humanised antibody) both sit in the middle of the immunogenicity spectrum. They are well-tolerated in clinical use but can rarely trigger immune reactions, which is why infusion protocols and premedication are standard.

How Much Does a Monoclonal Antibody Cost?

The answer differs considerably between branded originators, approved biosimilars, and Indian biosimilars:

Trastuzumab Price in India

Rituximab Price in India

The price difference between the originator and the Indian biosimilar rituximab is particularly striking: about 80 per cent lower. This price gap makes these medicines both more accessible to Indian patients and more attractive to counterfeiters, who can sell a fake product at a price that appears competitive with biosimilars but costs almost nothing to produce.

The Counterfeiting Risk: Why These Drugs Are Targeted

Monoclonal antibodies occupy the most dangerous intersection in pharmaceutical crime: they are expensive, they treat fatal conditions, and they are biologically complex enough that visual inspection cannot determine whether a vial contains the genuine drug or a substitute.

A vial of saline labelled as trastuzumab looks identical to a vial of genuine trastuzumab to the naked eye, to the patient, and in most cases to the healthcare worker preparing the infusion. The only way the patient learns they received a fake is when their cancer progresses weeks or months later, after the treatment window may have partly closed.

The WHO has issued a series of medical product alerts about falsified monoclonal antibodies. Its May 2025 alert regarding falsified Imfinzi (durvalumab), a monoclonal antibody used for non-small cell lung cancer, detected falsified batches in Iran and Turkey, with packaging discrepancies including text placement errors and a missing product price that only trained eyes would notice. This is not an isolated case. Previous alerts have covered falsified rituximab, bevacizumab, and trastuzumab at various points.

In India, the August 2026 Delhi Crime Branch operation that seized anti-cancer medicines worth ₹9 crore included vials labeled with multiple branded monoclonal antibodies, including immunotherapy agents in the same drug category as rituximab and trastuzumab.

Genuine Trastuzumab: Verified Manufacturers and How to Check

Verifying genuine trastuzumab starts with knowing the approved manufacturers.

Verified Trastuzumab Manufacturers Approved in India

• Roche/Genentech: Herceptin (originator); the reference product against which all biosimilars are compared

• Biocon: Canmab (trastuzumab biosimilar); DCGI-approved; widely used in Indian oncology centres

• Samsung Bioepis / MSD: Ontruzant; EU and India approved

• Pfizer: Zercepac; approved

• Mylan/Viatris: Ogivri; approved

Treat any vial of trastuzumab that does not carry one of these manufacturers' names, or any generic label that does not match a DCGI-approved biosimilar application, as unverified.

Genuine Trastuzumab Physical Verification Checklist

Genuine Rituximab: Verified Manufacturers and How to Check

Verifying genuine rituximab follows the same principles, but with a different list of approved manufacturers.

Verified Rituximab Manufacturers Approved in India

• Roche/Biogen: MabThera (originator); the reference product

• Dr Reddy's Laboratories: Reditux; first DCGI-approved rituximab biosimilar in India

• Intas Pharmaceuticals: Maball; DCGI-approved

• Hetero/Cipla: Mabtas; DCGI-approved

• Biocon: Kymriah (not rituximab); check specific rituximab biosimilar status separately

How to Source Monoclonal Antibodies: The Rituximab Supply Chain Check

How to source monoclonal antibodies safely requires understanding the Indian oncology medicine supply chain:

1. Procurement from hospital pharmacy: For hospitalised patients receiving rituximab as a chemotherapy infusion, the hospital pharmacy procures from authorised distributors tied to specific approved manufacturers. This is the most reliably controlled channel.

2. Outpatient sourcing with prescription: For patients sourcing for outpatient or home infusion (rare, and should involve a clinical team), a licensed pharmacy with full DCGI documentation and cold chain compliance is essential.

3. Documented distributor trail: A genuine rituximab vial should be traceable through a chain: manufacturer → DCGI-approved distributor → licensed pharmacy → patient. Each link in this chain should provide documentation.

Where to Source Trastuzumab and Rituximab in India

Where to source trastuzumab and rituximab safely in India:

Hospital oncology pharmacies: Major cancer centres Tata Memorial (Mumbai), Apollo Cancer Centres, HCG, Fortis, Manipal, AIIMS procure through manufacturer-authorised distributors under institutional purchase agreements. This is the most reliably authenticated supply chain available to patients.

Government schemes: The PM Jan Aushadhi scheme stocks selected biosimilar monoclonal antibodies including rituximab biosimilars at significantly reduced prices. Ayushman Bharat covers the cost of specified cancer medicines at empanelled hospitals; enquire with your treating oncologist about coverage before purchasing independently.

Licensed online pharmacies: Platforms such as MrMed that require a valid oncologist's prescription, provide a full GST invoice with batch documentation, source from licensed distributors with verified manufacturer relationships, and offer cold chain delivery for temperature-sensitive biologicals.

What to always require when purchasing:

• Valid prescription from a registered oncologist ✅

• Printed GST invoice with batch number, expiry, manufacturer name, and licensed distributor details ✅

• Confirmation that manufacturer matches the approved list above ✅

• Cold chain documentation: temperature log or validated cold delivery ✅

• Batch number checked against CDSCO drug alerts portal (cdsco.gov.in) ✅

Trastuzumab vs Rituximab: The Key Clinical Distinction

Trastuzumab vs rituximab: These are never interchangeable. Administering the wrong monoclonal antibody is not merely ineffective. It is potentially harmful, and it means the patient's actual cancer is going untreated during every cycle of the wrong drug.

Trastuzumab is for HER2-positive cancer only. Before prescribing, pathology testing must confirm HER2 overexpression or HER2 gene amplification (via IHC 3+ or FISH). A patient with HER2-negative breast cancer receives no benefit from trastuzumab and is exposed to its side effects, cardiac toxicity in particular, for nothing.

Rituximab is for CD20-positive B-cell malignancies or specific autoimmune conditions. It has no role in solid tumour oncology outside these specific indications.

The prescription, test results, and specific oncological indication should all be present before sourcing or administering either medicine.

FAQs

Q1. What are trastuzumab and rituximab used for?
Trastuzumab targets HER2 in breast and gastric cancer. Rituximab targets CD20 in B-cell lymphomas, leukaemia, and certain autoimmune conditions including rheumatoid arthritis. They are not interchangeable.

Q2. How do you verify genuine monoclonal antibodies?
Check the manufacturer against the DCGI-approved list, verify the batch number against CDSCO alerts, inspect the solution for clarity, confirm cold chain compliance, and buy only from a licensed pharmacy with a full GST invoice and batch documentation.

Q3. How much does a monoclonal antibody cost?
Originator trastuzumab (Herceptin) costs ₹75,000 to ₹1,00,000 per 440mg vial. Indian biosimilar trastuzumab costs ₹55,000 to ₹75,000. Rituximab biosimilars (Reditux, Maball) cost ₹8,000 to ₹15,000 per 500mg vial versus ₹50,000 to ₹70,000 for originator MabThera.

Q4. What are the four main types of monoclonal antibodies?
Murine (-omab), chimeric (-ximab), humanised (-zumab), and fully human (-umab) classified by how much of the antibody structure is derived from human versus animal sources.

Q5. Where to buy genuine trastuzumab and rituximab in India?
Licensed hospital oncology pharmacies, government health scheme dispensaries, or licensed online pharmacies such as MrMed with prescription verification, cold chain delivery, and full batch documentation.

Final Thoughts

Genuine trastuzumab and genuine rituximab are not simply expensive medicines. They are precision biological agents that work through molecular specificity, and a counterfeit that replaces them with saline not only fails to treat but actively deceives the oncologist into thinking treatment is proceeding.

The sourcing standard for monoclonal antibodies must be higher than for any other category of medicine. Manufacturer verification, cold chain documentation, CDSCO batch verification, and licensed pharmacy purchase are not optional precautions. They are clinical requirements that determine whether the patient receives treatment or a simulation.

MrMed provides licensed, prescription-required, cold chain-compliant access to approved trastuzumab and rituximab biosimilars in India with full batch traceability and a GST invoice for every order. The standard of care in cancer medicine sourcing should be no less rigorous than the treatment itself.

Read Also

1. How To Spot Fake Medicines: A Consumer's Guide

References

1. WHO [Internet]. Geneva: WHO; 2025 May 14 [cited 2026 Sep 01]. Medical product alert No. 3/2025: falsified IMFINZI (durvalumab) injection 500mg/10ml. Available from: https://www.who.int/news/item/14-05-2025-medical-product-alert-n-3-2025--falsified-imfinzi-(durvalumab)-injection-500mg-10ml

2. Eli Lilly Canada [Internet]. Toronto: Eli Lilly; [cited 2026 Sep 01]. Understanding monoclonal antibodies. Available from: https://www.lilly.com/en-CA/resources/faq/mounjaro-vial/real-fake-mounjaro

3. ANI News [Internet]. New Delhi: ANI; 2026 Aug 20 [cited 2026 Sep 01]. Delhi Crime Branch busts interstate anti-cancer drug racket, 17 arrested; medicines worth Rs 9 crore seized. Available from: https://aninews.in/news/national/general-news/delhi-crime-branch-busts-interstate-anti-cancer-drug-racket-17-arrested-medicines-worth-rs-9-crore-seized20260820145541/

Disclaimer: This article is for general informational and awareness purposes only. Trastuzumab and rituximab are prescription biological medicines. A qualified oncologist must prescribe them, a licensed pharmacy must supply them, and clinical supervision must oversee administration. Never source, store, or administer these medicines without appropriate medical and pharmaceutical oversight.