Halda’s HLD-0915 Shows Promising First-in-Human Results as a Safer RIPTAC Cancer Therapeutic
Halda Therapeutics presented first-in-human results for HLD-0915, an oral RIPTAC therapeutic, at the 2025 AACR-NCI-EORTC International Conference, showing promising signs of safety and anti-tumor activity in heavily pretreated metastatic castration-resistant prostate cancer (mCRPC) patients153.
Among patients completing at least two cycles, 59% achieved a PSA50 response (≥50% reduction in prostate-specific antigen) and 32% achieved a PSA90 response; all five patients with measurable disease achieved partial responses by RECIST criteria at first assessment153.
The drug was well-tolerated, with a favorable safety profile and low rates of treatment-related adverse events observed across all dose cohorts153.
RIPTACs (Regulated Induced Proximity Targeting Chimeras) represent a novel ‘hold-and-kill’ mechanism that leverages the overexpression of cancer-specific proteins (such as the androgen receptor) to selectively kill tumor cells while sparing healthy tissue263.
HLD-0915’s activity was observed even in patients with adverse molecular profiles and resistance to prior therapies, suggesting potential to overcome drug resistance mechanisms in advanced prostate cancer153.
Sources:
1. https://www.globenewswire.com/news-release/2025/10/24/3172912/0/en/Halda-Therapeutics-Announces-First-in-Human-Results-for-HLD-0915-an-Oral-RIPTAC-Therapeutic-Demonstrating-Encouraging-Safety-and-Anti-Tumor-Activity-in-Metastatic-Castration-Resist.html
2. https://www.fiercebiotech.com/biotech/vantai-plays-matchmaker-haldas-hold-and-kill-drugs-1b-deal
3. https://trial.medpath.com/news/dc48fb567d66adcd/halda-therapeutics-hld-0915-shows-promising-first-in-human-results-in-advanced-prostate-cancer
5. https://haldatx.com/halda-therapeutics-announces-first-in-human-results-for-hld-0915-an-oral-riptac-therapeutic-demonstrating-encouraging-safety-and-anti-tumor-activity-in-metastatic-castration-resistance-prost/