Johnson & Johnson is paying $3.05 billion to acquire Halda Therapeutics, obtaining a novel cell death platform while strengthening its prostate cancer franchise built on Erleada.
At the center of the acquisition is Halda’s regulated induced proximity targeting chimera (RIPTAC) platform, which gives rise to bifunctional small molecules that simultaneously bind a tumor-specific protein and a protein with essential function to cell survival in efforts to induce cancer cell death.
This novel “hold and kill” mechanism could address cancer’s ability to develop resistance by evolving bypass mechanisms, according to Halda.
Monday’s announcement comes shortly after Halda reported early phase 1 data for the platform’s lead candidate, HLD-0915, the crown jewel of J&J’s proposed $3.05 billion cash deal.
HLD-0915 targets androgen receptor and bromodomain 4 (BRD4). In an ongoing phase 1/2 trial, Halda enrolled 31 patients with metastatic castration-resistant prostate cancer (mCRPC) who had progressed on prior therapies, including at least one androgen receptor pathway inhibitor such as J&J’s Erleada. The patients may have received up to two prior taxane chemotherapies and may have also had prior exposure to radioligand therapy such as Novartis’ Pluvicto.
Among 22 patients who completed at least two cycles of the once-daily oral drug at various doses, 59% achieved a greater than 50% reduction in the prostate-specific antigen, and 32% of patients demonstrated a higher than 90% reduction, according to results presented at the AACR-NCI-EORTC triple meeting last month.
Halda described treatment-related adverse events (TRAEs) as “infrequent and generally low grade.” One patient who received the drug at the highest, 100-mg dose experienced dose-limiting toxicity of liver enzyme and bilirubin elevations. All grade 3 or above TRAEs across doses were reversible, and no treatment-related deaths were reported, according to the Boston biotech.
Based on the results, Halda has selected the two middle doses tested—25 mg and 50 mg—for dose expansion testing to determine the dose for registrational studies.
J&J’s R&D head of innovative medicine, John Reed, M.D., Ph.D., said in a Nov. 17 press release that HLD-0915 demonstrated “impressive preliminary efficacy and a strong early safety profile” from the phase 1/2 results. The company plans to accelerate the ongoing study, he said.
“Given the existing unmet need, this once-daily therapy has the potential to transform patient outcomes with its novel precision cancer cell-killing approach that can overcome mechanisms of resistance to treatment,” J&J said in the release.
The proposed acquisition will further beef up J&J’s pipeline in prostate cancer, on which the pharma company has placed many bets beyond the FDA-approved Erleada and Akeega.
J&J recently advanced pasritamig, a T-cell engager targeting kallikrein 2 (KLK2), into phase 3 testing as a monotherapy in late-line mCRPC. Another phase 3 is being planned that will pair the bispecific with docetaxel. Previously, the company’s anti-KLK2 radioligand therapy candidate, JNJ-6420, was linked to four deaths in an early-stage trial.
In a phase 1 trial conducted in pretreated mCRPC patients, pasritamig at the recommended phase 2 dose achieved a 42.4% PSMA50 response rate.
As part of its $2 billion acquisition of Ambrx Biopharma last year, J&J also obtained an antibody-drug conjugate targeting PSMA, the same target as Pluvicto.
In addition to HLD-0915, Halda’s RIPTAC-based pipeline also includes several earlier-stage candidates for breast, lung and other tumor types. The platform may also help create targeted therapies beyond oncology, J&J noted.
“This acquisition further strengthens our deep oncology pipeline with an exciting lead asset in prostate cancer and a platform capable of treating multiple cancers and diseases beyond oncology, providing a potential mid- and long-term catalyst for growth,” Jennifer Taubert, J&J’s chair of innovative medicines, said in a Nov. 17 statement. “We look forward to combining Halda’s pipeline, platform and people with our world class R&D, commercial and manufacturing capabilities and advancing our goal of bringing these therapies to patients around the world.”
In a separate release, Halda said the transaction is expected to close “within the next few months.”
Full-on acquisitions—versus licensing—appear to be on the rise among Big Pharma lately. Pfizer just beat out Novo Nordisk to acquire obesity biotech Metsera for up to $10 billion, with a once-monthly injectable GLP-1 candidate as the deal’s centerpiece. Merck & Co. is shelling out $9.2 billion to take over Cidara Therapeutics, along with a non-vaccine influenza prevention med that was ditched by J&J.