Johnson & Johnson successfully completed its acquisition of Halda Therapeutics, a clinical-stage biotechnology firm, for $3.05bn in the final quarter of 2025. The deal integrates Halda’s sought after proprietary Regulated Induced Proximity Targeting Chimera platform (RIPTAC) into J&J’s oncology portfolio, strengthening its R&D position.
Clinical status and outlook
The acquisition includes lead candidate HLD-0915, an oral therapy currently in phase 1/2 trials for metastatic castration-resistant prostate cancer (mCRPC). The FDA has granted HLD-0915 fast track designation, reflecting its potential for patients with disease progression despite standard hormonal therapies. Before the acquisition, Halda released promising “first-in-human” results at the AACR-NCI-EORTC conference in October 2025.
Beyond prostate cancer, the RIPTAC platform is being leveraged to develop candidates for breast and lung cancers. Jennifer Taubert, Executive Vice President, Innovative Medicine, J&J, explains: “This strategic milestone underscores our commitment to redefining cancer treatment with breakthrough science and transformative medicines. We are excited to formally welcome the talented Halda team to Johnson & Johnson and look forward to working together to achieve our shared goal of eliminating cancer.”
The mechanism: a novel “hold and kill” approach
For the pharmaceutical industry and healthcare providers, cancer cell resistance remains a formidable barrier, as tumours frequently evade traditional precision therapies by evolving complex bypass mechanisms. The RIPTAC platform offers a potential advantage by bypassing these common failure points; its ‘hold and kill’ mechanism does not require the target protein to be oncogenic or even functionally active to trigger cell death.
On top of this, RIPTACs act as a molecular bridge, creating a stable complex between a targeting tumour cell protein and a protein involved in effector cell survival. This leads to selective cell death in tumour cells, offering a potential route around standard resistance pathways.
As Prof John Reed, Executive Vice President, Innovative Medicine, R&D, J&J, says: “Halda’s innovative technology is designed to work even when cancers no longer respond to standard treatments using a novel mechanism that enables the selective killing of cancer cells.”
