Johnson & Johnson to Acquire Preclinical DAC Pioneer Firefly Bio for $1 Billion

Jun 09, 2026 12:25 CST Updated 12:25

Johnson & Johnson

Medical Device R&D and Manufacturer

Firefly Bio

Cancer Treatment Platform Developer

Johnson & Johnson Announces Final Agreement to Acquire Preclinical Biotech Company for $1 Billion in CashFirefly Bio, StrongVenturing into the Field of Degradant-Antibody Conjugates (DACs).

Under the sustained attention of Merck, Roche, BMS, and Pfizer, DACs have emerged as a new frontier in antibody-drug conjugate (ADC) development. With Johnson & Johnson’s entry into the field through its acquisition of the first DAC company, the rise and advancement of DAC technology are likely to accelerate.

Johnson & Johnson's Acquired DAC Platform

Firefly Bio is a startup biotechnology company that emerged from stealth mode in February 2024 with a $94 million Series A financing round. Notably, Eli Lilly participated in the company’s Series A financing, making itShareholders of Firefly Bio, Inc.

Firefly focuses on the development of degrader antibody conjugates (DACs), with proprietaryFirelink™ DAC Platform, viaFirelink conjugation technology links antibodies andConjugation with protein degraders to develop next-generation antibody-drug conjugates (ADCs), aiming to overcome existing ADC resistance andConquering “Undruggable” Targets to Further Unlock the Potential of Antibody-Drug Conjugates

Firefly'sDACPlatform UsagePotent catalytic protein degraders as payloads, and through proprietaryFirelink Linkage Technology reduces the leakage of free payload in the bloodstream, minimizing damage to healthy cells. It also lowers the required therapeutic dose, thereby enhancing safety and reducing costs.

According toAs disclosed by Firefly Bio, Inc.,In preclinical studies of solid tumors and hematologic malignancies, Firefly’s DACA single dose significantly reduced tumor volume at an extremely low dose.。

Johnson & Johnson, upon completion of theFollowing the acquisition of Firefly Bio, Inc., it will obtainFirefly’s DAC platform, as well as multiple preclinical solid tumor projects. According to the disclosure,Johnson & Johnson plans to leverage Firefly’s DAC platform,DevelopmentKRAS-TargetedDAC, for the treatment ofKRAS Gene Mutationdriven tumors,KRAS is widely considered “undruggable.”

The transaction is expected to be completed later this year, subject to obtaining the relevantRegulatory approval and satisfaction of other customary closing conditions.

The Rise of DAC

DAC is a novel therapeutic strategy derived from antibody-conjugation technology, distinct from traditional ADC drugs.(Traditional ADC drugs link antibodies toCytotoxic Small Molecule Drug Conjugates），The payload of DACs is protein degraders.，Its cytotoxicity is not dependent onhigh-concentration toxin molecules, but ratherViaProtein Degraders forUbiquitination and degradation of the target protein, andCan dissociate from the complex and continue to participate in the nextSecondary degradation cycle. Thissuggesting that high efficacy and durable therapeutic effects can be achieved with low doses, potentially overcoming existing resistance to antibody-drug conjugates (ADCs). Furthermore, the most promising prospect of DAC lies in itsCapableTargeting Pathogenic Proteins Previously Considered "Undruggable"。

Pharmaceutical giants have long been closely monitoring the potential demonstrated by DACs.

September 2023,Seagen (now part of Pfizer) paid Nurix Therapeutics $60 million to collaborate on the development of DACs. The partnership remains in place following Pfizer’s acquisition of Seagen.Nurix's R&D pipeline lists the collaboration as an exploratory-stage project.

In November 2023, BMSSecured a total of $180 million (with an upfront payment of $100 million)Orum Therapeutics' DAC Drug ORM-6151（BMS-986497），This drug employs an anti-CD33 antibody to deliver a GSPT1 degrader and has entered Phase I clinical trials for acute myeloid leukemia and myelodysplastic syndromes.

In December 2023, Merck & Co. andC4 Therapeutics has reachedA collaboration agreement totaling $610 million, including a $10 million upfront payment and $600 million in milestone payments, was established to jointly develop DAC drugs. However, the agreement was terminated by Merck & Co. in November 2025.

July 2024,Vertex andOrum Therapeutics Enters into Collaboration Agreement to Develop Up to Three DAC Drugs, with Total Deal Value Reaching $945 Million

April 2026, RocheandC4 TherapeuticsStrategic Partnership for Joint DevelopmentDAC drugs. The total value of this collaboration could exceed $1 billion.

In June 2026, Johnson & Johnson announced a $1 billion acquisitionFirefly Bio, the first DAC company acquired by an MNC.

With increasing attention from major pharmaceutical companies and capital injection, DAC is poised for accelerated development.

References:

1.https://www.investor.jnj.com/investor-news/news-details/2026/Johnson--Johnson-to-Acquire-Firefly-Bio-Inc--to-Expand-Oncology-Pipeline-with-Novel-Degrader-Antibody-Conjugate-Platform/default.aspx

2.https://www.fiercebiotech.com/biotech/jj-makes-1b-upfront-bet-emerging-dac-space-netting-firefly-bio

3.https://fireflybiologics.com/press-release-firefly-bio-debuts-with-94-million-series-a-financing/