Bristol Myers Ends the Cellares Deal After a Scale Test

Bristol Myers Squibb has ended its $380 million manufacturing pact with Cellares after finding the Cell Shuttle could not make Breyanzi at commercial scale. A company spokesperson told Reuters on Tuesday the automated platform missed the requirements for that blood-cancer CAR-T, which posted $1.36 billion in 2025 sales.

Cellares will cut 100 jobs by Oct. 20. The customer that had reserved machines in the United States, Europe and Japan is gone, and the commercial-scale test that deal was built to run has come back as a no.

Bristol Myers Walks After a Commercial-Scale Test

Endpoints News first reported the split on Tuesday, writing that Bristol Myers pulled out after a “comprehensive evaluation.” Reuters then named the product. The spokesperson said Cellares’s Cell Shuttle could not meet the requirements to make Breyanzi, the company’s CD19 CAR-T for lymphoma and other blood cancers, at commercial scale. Reuters also reported that the decision applies only to Breyanzi and its approved manufacturing process.

Cellares did not immediately comment to Reuters. Two days earlier, co-founder and chief executive Fabian Gerlinghaus had already told staff and the industry, without naming the buyer, that a large pharmaceutical customer had ended its partnership and that the loss required the company to “resize.”

WHAT WE KNOW

• The product: Bristol Myers tied the exit to commercial-scale manufacture of Breyanzi, not to a pause in the drug itself.
• The jobs: A California WARN filing lists 100 Cellares Corporation roles in San Mateo County, with a last day of Oct. 20, 2026, and 60 days’ notice dated Aug. 21.
• The remaining book: A Cellares spokesperson told BioPharma Dive the firm has more than doubled the number of customers it serves since the start of the year, and Gerlinghaus said those customers have restated their work with the company.

WHAT IS UNCONFIRMED

• Cash already paid: Neither company has said how much of the 2024 package of upfront and milestone money actually changed hands.
• Other BMS programs: The 2024 text covered “select” CAR-T assets; Reuters limited Tuesday’s decision to Breyanzi’s approved process, and other pipeline transfers have not been publicly closed or confirmed.
• Headcount math: Cellares has not published a total workforce figure, so the 100 cuts have no official share of staff attached.

Breyanzi has been on the U.S. market since 2021. Taking a product with that much commercial history and moving it onto a new automated line is a different job from starting a trial on that line. That is the test Bristol Myers paid Cellares to run.

A $380 Million Reservation Across Three Continents

On April 22, 2024, the companies announced a worldwide capacity reservation and supply agreement valued at up to $380 million in milestone payments and upfront cash. Cellares would optimize, automate, and tech-transfer select Bristol Myers CAR-T therapies onto Cell Shuttle, then dedicate multiple Shuttle units and Cell Q quality-control systems for Bristol Myers’s exclusive use in automated plants in the United States, the EU, and Japan.

Lynelle B. Hoch, then president of Bristol Myers’s Cell Therapy Organization, said the collaboration strengthened the company’s existing internal manufacturing for CAR-T by adding “the first end-to-end fully automated cell therapy manufacturing platform.” Gerlinghaus said the same week that the pact fit Cellares’s plan to put high-throughput automated factories in the markets where the therapies would be used. Cellares pitched the Shuttle as a way to make far more batches with the same floor space and headcount as a conventional contract shop, and it had claimed 90% less labor and a 50% lower batch price than those shops.

The 2024 paper did not appear from nowhere. It sat on two earlier Bristol Myers moves in August 2023: a seat in Cellares’s $255 million Series C, which was meant to finish the first commercial-scale plant in Bridgewater, New Jersey, and a slot in the Technology Adoption Partnership program to run proof-of-concept manufacturing. In October 2023 the companies added a second CAR-T to that evaluation track. By the time the capacity reservation was signed, Bristol Myers had already spent a year looking at the machine.

THE BMS-CELLARES CLOCK

1. August 2023: Bristol Myers joins Cellares’s TAP program and participates in the $255 million Series C.
2. October 2023: The TAP work expands to a second Bristol Myers CAR-T.
3. April 22, 2024: The companies sign the worldwide capacity reservation, valued at up to $380 million.
4. April 1, 2025: The FDA’s CBER arm grants Cell Shuttle an Advanced Manufacturing Technology designation.
5. June 15, 2026: Cellares grows its Series D to $327 million and still lists Bristol Myers among Cell Shuttle sponsors.
6. August 21, 2026: Gerlinghaus posts that a large customer has left and that Cellares must resize; the California WARN notice is dated the same day.
7. August 25, 2026: Bristol Myers confirms the break and ties it to Breyanzi at commercial scale.

From Series C to the reservation, the public story was that a major CAR-T seller was putting real volume, and real money, on the automated line. Tuesday’s comment is the first time that seller has said the line could not carry the commercial product.

Why Moving Breyanzi Onto New Machines Is Hard

Autologous CAR-T starts with a patient’s own T cells, which are genetically reprogrammed in a plant and infused back. Every change in equipment, software, or handling can shift yield, impurities, or timing, and an approved commercial process has to show the new line matches the old one. That comparability bar is higher than the bar for a trial product that has lived on the new line from the start.

Cellares’s pitch was that Cell Shuttle would take that entire chain (enrichment, selection, gene transfer, activation, expansion, formulation) and run it without a room full of manual steps. In April 2025 the company said Cell Shuttle was the first cell therapy manufacturing platform to receive an Advanced Manufacturing Technology designation from CBER, a tag under the FDA’s Advanced Manufacturing Technologies designation program that Cellares said would give clients using the Shuttle faster review on INDs and BLAs. In June 2026 Cellares said it had also been accepted into the FDA’s first Manufacturing PreCheck cohort, the only cell therapy platform among seven companies in that group.

Those regulatory badges did not substitute for Bristol Myers’s own commercial-scale check on Breyanzi. The 2024 reservation asked Cellares to take a living, high-volume brand and put it on new hardware across three regions. Two years later the buyer says the hardware did not meet the requirements of that brand’s approved process. That finding can sit next to Cellares’s own claim, in its Series D materials, of a 100% automation success rate across more than a dozen automated processes, because a trial run that meets release specs is not the same file as a licensed commercial comparability package.

The industry reading that followed the Reuters note treated the miss as a scale problem, not a press-release feud. One reply in that discussion argued the LinkedIn note was ordinary layoff context and that Bristol Myers was not picking a fight. The substance still sits in the spokesperson’s sentence: the Shuttle, as tested, could not make Breyanzi the way Bristol Myers needs it made.

Cabaletta Keeps a 10-Year Slot on the Same Line

The customer that left was the one whose cash and volume had been used, in Cellares’s own fundraising copy, to “de-risk” a global factory build. The customers that remain are mostly writing a different kind of contract. They are putting new or clinical programs onto the Shuttle instead of moving a billion-dollar approved brand onto it.

Cabaletta Bio is the clearest case. On April 28, 2026, Cellares and Cabaletta announced a 10-year commercial supply deal for rese-cel (resecabtagene autoleucel), an investigational CAR-T for autoimmune disease. The companies said patients had already been dosed with an autologous CAR-T made on the automated platform, and that the Shuttle and Cell Q systems could support thousands of batches a year if the drug is approved. Cabaletta’s commercial supply agreement with Cellares, described in its SEC filings, sits on top of a January 2026 clinical supply pact and an IND amendment that cleared Shuttle-made product for the RESET program. Cabaletta has also kept other plants in the mix. In its Aug. 13 earnings update it said ElevateBio would join Lonza as a CDMO for rese-cel’s closed, partly automated process, a dual-source plan that does not depend on a single automated vendor.

Cellares’s June Series D release also named TScan Therapeutics and ProTgen as Cell Shuttle sponsors, and its newsroom later posted automation pacts with Sonoma Biotherapeutics (an engineered Treg program) and Papillon Therapeutics. Gerlinghaus wrote after the Bristol Myers loss that he had spoken with customers over two weeks and that several were discussing extra programs, faster work, and a path toward commercial manufacturing. That is a real book of clinical and mid-stage work. It is not a replacement, in volume or in cash timing, for exclusive commercial capacity on a $1.36 billion lymphoma product.

One Hundred Jobs End by Oct. 20

The human cost showed up in a California filing before Bristol Myers confirmed its name. Cellares Corporation told the state’s Employment Development Department it would cut 100 jobs in San Mateo County, home of its South San Francisco headquarters, with employment ending by Oct. 20. BioPharma Dive reported that the roles are primarily software engineers, quality-control and design staff, and manufacturing specialists. Cellares’s main commercial-scale plant is in Bridgewater, New Jersey, with more factories planned in Leiden in the Netherlands and in Japan, so the California notice is a headquarters and engineering cut as much as a shop-floor one.

A large pharmaceutical customer recently made the decision to end its partnership with Cellares. This was a decision specific to that customer. The loss of this partnership requires us to resize the company.

Fabian Gerlinghaus, CEO and co-founder of Cellares, LinkedIn, Aug. 21, 2026

He asked people seeking a resume book to write hr@cellares.com and said the company would support those leaving. He also drew a line under the technology, writing in the same post (as Fierce Pharma later quoted) that he wanted to be clear the technology is proven in the clinic. That clinic proof is the Cabaletta dosing and the IND amendment. It is not the Breyanzi commercial file.

WHO IS ON THE NOTICE

• Software engineers: The control stack that runs walk-away automation is in the first row of roles being cut.
• Quality-control staff: Cell Q was sold as the high-throughput QC pair to Cell Shuttle; QC jobs are on the same WARN list.
• Design staff: Platform and factory design work is being reduced as exclusive BMS capacity comes off the plan.
• Manufacturing specialists: Hands-on Shuttle and plant roles are included, even with Bridgewater still listed as the commercial-scale site.

The timing sits next to a still-open checkbook. On June 15 Cellares said Prime Radiant Partners had put in $50 million and taken the Series D to $327 million, after a $257 million first close in January led by BlackRock and Eclipse. The June release said that money would finance the company through the start of commercial-scale operations and an IPO in 2027, and would fund the Leiden plant, which it said would be GMP-ready in 2027. ARK Invest, T. Rowe Price Investment Management, Duquesne Family Office, Baillie Gifford, and Gates Frontier were among the names on the cap table. That round still listed the $380 million Bristol Myers manufacturing agreement as an anchor of the pipeline. Ten weeks later the anchor customer is gone and 100 people are on a 60-day clock.

In Devens, Summit and Bothell, the Line Already Runs

Bristol Myers did not need Cellares in order to keep selling Breyanzi. Hoch’s 2024 quote framed the Shuttle as an add-on to plants the company already ran. A Bristol Myers cell-therapy operations sheet lists four clinical and commercial sites and one more facility underway, with about 5,000 people in the cell-therapy organization and more than 15,000 patients treated in trials and commercial use. The named U.S. map is Bothell, Washington; Warren and Summit, New Jersey; and Devens, Massachusetts, plus Leiden in the Netherlands and external partners in Europe and Japan.

Devens is the newest of those commercial rooms. The FDA cleared commercial cell-therapy production there in 2023 in a 244,000-square-foot cell-therapy block on a larger biologics campus. Bothell has supported Breyanzi and investigational work. Summit has handled commercial ide-cel (Abecma). When a contract manufacturer misses a comparability or throughput bar, that network is what a company of this size falls back on. Bristol Myers has also been rearranging pieces of it; in 2025 it told Fierce Pharma it would stop viral-vector work at a former Novartis plant in Libertyville, Illinois, and shift that work to Devens.

Cellares still has a clinical story, a June round, a Leiden shell dated 2027, and a 10-year paper with Cabaletta. It no longer has the exclusive commercial reservation that was supposed to fill Shuttle bays in three regions for a product that already sells more than a billion dollars a year. The 100 California jobs end on Oct. 20. Breyanzi stays on Bristol Myers’s own line.