Before BMS, the idea that a patient’s own immune system could be weaponized against a tumour was considered fringe science. Opdivo and Yervoy changed that. Then a $74 billion acquisition of Celgene changed Bristol Myers Squibb itself,from a $15.9 billion company into a $48.3 billion one, with a pipeline stretching from checkpoint inhibitors to CAR-T cell therapy.
For most of the twentieth century, oncology had three tools: surgery, radiation, and chemotherapy. Each attacked the tumour directly. The immune system,the body’s own surveillance network,was considered irrelevant to cancer treatment, a bystander that tumours had learned to evade. The researchers who argued otherwise spent decades in the scientific wilderness. James Allison studied CTLA-4, a protein that acts as a brake on T cells, at a time when most oncologists dismissed immunotherapy as wishful thinking. Tasuku Honjo, working independently in Japan, identified PD-1, another immune checkpoint receptor. Both would eventually share the 2018 Nobel Prize in Physiology or Medicine. But before Stockholm, there was Bristol Myers Squibb.
BMS did what the scientific establishment would not: it bet real capital on checkpoint inhibition. Yervoy (ipilimumab), the first anti-CTLA-4 antibody, received FDA approval in 2011 for metastatic melanoma. It was the first drug ever shown to extend overall survival in advanced melanoma in a randomised trial. Patients who had been told they had months to live were, in some cases, still alive years later. The survival curves did something oncologists had almost never seen,they flattened into a plateau, suggesting durable responses rather than temporary remissions.
Then came Opdivo (nivolumab), a PD-1 inhibitor. Where Yervoy released one brake on the immune system, Opdivo released another. The two drugs could be combined. The logic was simple in principle and extraordinarily complex in execution: block both CTLA-4 and PD-1, and you remove two separate mechanisms tumours use to hide from immune cells. The Opdivo-plus-Yervoy combination became a backbone regimen across multiple tumour types,melanoma, renal cell carcinoma, non-small cell lung cancer, hepatocellular carcinoma. BMS had not merely developed a drug. It had validated an entire therapeutic paradigm.
On 3 January 2019, Bristol Myers Squibb announced it would acquire Celgene Corporation for approximately $74 billion. The deal closed in November of that year. It was the largest pharmaceutical acquisition in history at the time, and the market was sceptical. BMS’s share price dropped on the announcement. Analysts questioned whether the company was overpaying. Celgene’s flagship drug, Revlimid (lenalidomide), faced looming generic competition. The bull case depended on Celgene’s pipeline delivering. The bear case said BMS was buying a company whose best years were behind it.
The bull case proved correct. Revlimid, a treatment for multiple myeloma and other haematological malignancies, continued generating substantial revenue through its patent protection period, providing the cash flow BMS needed to fund pipeline development. But the real prize was what came with it. Breyanzi (lisocabtagene maraleucel), a CAR-T cell therapy for large B-cell lymphoma, gave BMS a foothold in cell therapy,a manufacturing paradigm where the drug is the patient’s own re-engineered immune cells. Abecma (idecabtagene vicleucel), another CAR-T product, extended that position into multiple myeloma. Reblozyl (luspatercept) addressed anaemia in myelodysplastic syndromes. The Celgene acquisition did not just add revenue. It gave BMS capabilities in cell therapy manufacturing that would have taken a decade to build internally.
The arithmetic tells the story. In 2014, before the Celgene acquisition was even contemplated, BMS reported revenue of $15,900 million. By 2024, the combined entity posted $48,300 million,7 per cent growth that year, with the Growth Portfolio contributing $11.2 billion, up 19 per cent. The company had also delivered $1.5 billion in cost savings from the integration. A $74 billion bet had, by the numbers, paid off.
India presents a particular problem for immuno-oncology companies. The country has 1.4 billion people, a growing cancer burden, and a patent regime that is, by design, sceptical of pharmaceutical monopolies. Section 3(d) of the Indian Patents Act sets a higher bar for patentability than most jurisdictions, requiring applicants to demonstrate enhanced therapeutic efficacy rather than mere novelty. Evergreening,the practice of extending patent life through minor modifications,is explicitly targeted. For a company whose value rests on biologic innovation, India is both a massive potential market and a jurisdiction that forces you to prove your science is genuinely new.
BMS has filed 883 patent applications in India, of which 57 have been granted. That grant rate,roughly 6.5 per cent,reflects the stringency of Indian patent examination, not a failure of the applications themselves. The filing pattern spans from 1998 to 2026, tracking BMS’s evolution from a mid-size pharmaceutical company to an immuno-oncology powerhouse. The early filings covered cardiovascular and metabolic compounds. The later filings reflect the checkpoint inhibitor portfolio, the Celgene pipeline, and the cell therapy platform. Each filing is a legal claim on the Indian market for a specific molecule, formulation, or process,and each must survive examination under rules designed to ensure that patents serve the public interest.
The 57 granted patents represent the molecules and processes that cleared that bar. They are the intellectual property that gives BMS the legal basis to market its innovations in a country where generic competition is both fierce and socially valued. For a company that invested $11.1 billion in R&D in 2025 alone, the Indian patent portfolio is not peripheral. It is the mechanism through which BMS’s science reaches a fifth of the world’s population.
Revenue trajectories in pharmaceuticals are rarely smooth. Patents expire. Blockbusters face generic competition. Pipelines fail. The standard narrative for a major pharma company is a cycle of growth followed by a patent cliff, followed by a desperate scramble to fill the gap. BMS has lived through this cycle more than once. What makes the company’s growth from $15,900 million in 2014 to $48,300 million in 2024 unusual is not the magnitude,it is the mechanism.
Most pharmaceutical companies that triple in size do so through a series of incremental acquisitions, each adding a few billion in revenue. BMS did it with one defining transaction and a decade of pipeline execution. The Celgene acquisition provided the step change. But the 2025 numbers show what happened next: the Growth Portfolio,which includes Opdualag (a next-generation checkpoint combination), Camzyos (mavacamten, for obstructive hypertrophic cardiomyopathy), Reblozyl, and Breyanzi,reached $26.4 billion, up 17 per cent year over year. The company has committed to delivering 10 or more new medicines and 30 or more new indications by 2030.
That target is not aspirational language. It is a manufacturing and clinical-trial commitment that requires the company to advance dozens of programmes simultaneously across oncology, haematology, immunology, and cardiovascular disease. The $11.1 billion R&D investment in 2025 is the cost of running that many programmes at scale. BMS is not coasting on Celgene’s legacy. It is executing a pipeline strategy that depends on the infrastructure Celgene gave it,particularly in cell therapy, where manufacturing complexity dwarfs anything in traditional biologics.
Sources: BMS Annual Reports 2014–2025. Indian Patent Office (patent filing data). OPPI member directory.