Bristol-Myers Squibb Company (NYSE:BMY) has ended its partnership with cell-therapy manufacturer Cellares after determining that Cellares’ Cell Shuttle platform could not meet the requirements needed to manufacture Breyanzi at commercial scale. The partnership, announced in 2024, was valued at up to $380 million and was intended to expand Breyanzi manufacturing capacity across the U.S., Europe, and Japan.
Breyanzi remains an important product for BMY, generating $1.36 billion in sales in 2025. The termination raises questions about BMY’s ability to scale production of its growing CAR-T franchise efficiently, even though the company said the decision is specific to Cellares’ platform and Breyanzi’s established manufacturing process.

Bull Case
The biggest positive for Bristol-Myers Squibb Company (NYSE:BMY) is that the company appears to be protecting product quality and commercial reliability rather than continuing with a manufacturing partnership that did not meet its requirements. BMY determined that Cellares’ system was not suitable for commercial-scale Breyanzi production. Walking away from the agreement could help prevent manufacturing issues from affecting supply or product consistency as demand grows.
The termination also does not mean BMY is abandoning Breyanzi or CAR-T therapy. Reuters reported that the decision applies to Cellares and its manufacturing platform, rather than Breyanzi itself. With Breyanzi already generating substantial revenue, BMY still has an opportunity to expand the drug through its existing manufacturing network and other capacity investments.
BMY also has broader growth drivers beyond Breyanzi. The company recently received FDA accelerated approval for ZENBEXUS (iberdomide) in combination therapy for certain multiple myeloma patients, supporting its efforts to build its newer growth portfolio.
From an investor perspective, the decision could be viewed as disciplined capital allocation. Instead of continuing to spend on a platform that failed to meet commercial requirements, BMY can redirect resources toward manufacturing capabilities and medicines with stronger execution potential.
Bear Case
The biggest concern is that the Cellares termination highlights how difficult and expensive it can be to scale CAR-T manufacturing. CAR-T therapies require highly individualized manufacturing processes, making them more complex than conventional drugs. Reuters noted that the development highlights broader manufacturing challenges facing the CAR-T industry.
That matters because Breyanzi is becoming an increasingly important contributor to Bristol-Myers Squibb Company (NYSE:BMY)’s growth. If the company cannot expand manufacturing capacity efficiently, production constraints could limit the drug’s ability to meet additional demand.
There is also an opportunity-cost issue. The original Cellares agreement was designed to provide manufacturing capacity across several major markets. Ending the partnership means BMY will need to rely on alternative manufacturing arrangements or develop additional internal capacity. That could require more time and capital as the company expands its cell-therapy business.
The development also raises a broader question about BMY’s execution in cell therapy. The company acquired Celgene partly to strengthen its position in oncology and cell therapies, and Breyanzi is one of the products tied to that strategy. If BMY cannot scale its manufacturing infrastructure smoothly, the growth trajectory could be less efficient than investors had expected.
Conclusion
The Cellares termination looks more like a manageable setback than a fundamental problem for Bristol-Myers Squibb Company (NYSE:BMY) based on the information currently available. Breyanzi remains commercially important, and BMY’s decision to end the agreement suggests management is unwilling to compromise on manufacturing standards simply to add capacity.
The main risk is that finding replacement capacity could take longer or cost more than expected, limiting Breyanzi’s growth. Still, because the issue is specific to Cellares’ manufacturing platform rather than the drug itself, the bull case remains intact as long as BMY can expand Breyanzi production through alternative channels.
Overall, the news is moderately negative for near-term execution but not enough by itself to undermine the broader BMY investment story. The key factor for investors will be whether BMY can demonstrate that it has enough manufacturing capacity to support continued Breyanzi growth.
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Disclosure: None. This article is originally published at Insider Monkey.






