Johnson & Johnson Acquires Ambrx Biopharma for US$2 billion to Develop ADC Drugs

On January 9, Johnson & Johnson announced that it had reached a final agreement to acquire Ambrx Biopharma. Ambrx Biopharma is a clinical-stage biopharmaceutical company developing its proprietary synthetic biology technology platform for the design and development of next-generation antibody drug conjugates (ADCs). The total equity value of the all-cash merger transaction is approximately $2 billion, net of $1.9 billion after deducting expected acquisition cash. The transaction is expected to be completed in the first half of 2024.

Ambrx was spun off from Scripps Research in 2003. The company has pioneered a platform to expand the genetic code technology, using industry-standard cell lines to add synthetic amino acids (SAA) to proteins at any site of choice. Through SAA, uniform and stable conjugation can be performed at specific sites, overcoming the limitations of traditional conjugation technology and achieving engineered precision biological preparations.

At this stage, Ambrx is advancing a series of focused clinical and preclinical programs aimed at optimizing the efficacy and safety of its candidate therapies in multiple cancer indications, including ARX517, a proprietary ADC targeting prostate-specific membrane antigen (PSMA), for the treatment of metastatic castration-resistant prostate cancer (mCRPC); and ARX788, a proprietary ADC targeting the human epidermal growth factor receptor (HER2), for the treatment of metastatic HER2+ breast cancer; Also included is ARX305, a proprietary ADC targeting type II transmembrane protein (CD-70) for the treatment of renal cell carcinoma.

Dr. Yusri Elsayed, Global Therapeutic Area Head, Oncology, Johnson & Johnson, noted: "Ambrx’s ADC technology is uniquely positioned to stabilize antibody and cytotoxic linkage payloads, resulting in engineered ADCs that effectively kill cancer cells and limit toxicity. ARX517 has shown promising results to date in the treatment of metastatic castration-resistant prostate cancer (mCRPC) and represents a potential first-in-class targeted therapy for the treatment of this aggressive disease. In addition, Ambrx's pipeline and ADC platform provide us with substantial opportunities as we hope to transform cancer treatment and improve patients' lives by delivering enhanced precision biologics. "

The planned acquisition provides Johnson & Johnson with the opportunity to design, develop and commercialize targeted oncology therapies. Ambrx's proprietary ADC technology combines the advantages of a highly specific targeting monoclonal antibody securely coupled with a potent chemotherapy payload to deliver targeted and efficient destruction of cancer cells without the side effects typically associated with chemotherapy. Building on its tradition of innovation in oncology and prostate cancer, Johnson & Johnson scientists intend to collaborate with Ambrx researchers to accelerate the Phase 1/2 APEX-01 study of ARX517 in advanced prostate cancer while advancing the development of novel ADC product candidates.

Margaret Yu, MD, Ph.D., disease area leader for prostate cancer at Johnson & Johnson Innovative Medicines, said: "There are still significant unmet needs in the treatment of mCRPC. We see a unique opportunity to leverage the potential of Ambrx's innovative ADC platform, and with our deep understanding of prostate cancer, we will deliver a PSMA-targeted therapy to meet the growing needs of the more than 185,000 patients with metastatic castration-resistant prostate cancer today. "