Heidelberg Pharma AG will present new clinical data from its ongoing Phase I/IIa study of HDP-101 at the 16th Annual World ADC Congress in San Diego, California, from November 3-6, 2025. The data demonstrate objective responses and promising anti-tumor activity observed in several patients across multiple cohorts in the clinical trial for relapsed or refractory multiple myeloma.
The findings reinforce the therapeutic potential and safety profile of HDP-101, an anti-BCMA antibody-drug conjugate being investigated for the treatment of multiple myeloma, a bone marrow cancer with high unmet medical need. Professor Andreas Pahl, Chief Executive Officer of Heidelberg Pharma, will present an update from patient cohort 8 including efficacy data of the open-label, multicenter study during a presentation titled "From Bench to Breakthrough: The Evolution of Amanitin ADCs - Insights from HDP-101 Phase I/II & the Future of Payload Differentiation" on Wednesday, November 5, 2025, at 5:00 pm PST.
Following the World ADC Congress, Heidelberg Pharma will host an R&D webinar on November 11, 2025, at 05:00 pm CET for investors, analysts, and media. The webinar will feature presentations by the Heidelberg Pharma management team alongside Key Opinion Leader Professor Marc-Steffen Raab, Head of the Myeloma Center at the University Hospital Heidelberg and clinical investigator of the study. Participants can register for the webinar at https://us06web.zoom.us/webinar/register/WN_AG_mESPaT-aSsm8_O2Dll.
HDP-101 represents a significant advancement in cancer treatment as Heidelberg Pharma is the first company to use the compound Amanitin from the green death cap mushroom in cancer therapy. The biological mechanism of action of the toxin represents a new therapeutic modality used in the company's ATAC technology platform. This innovative approach combines the specificity of antibodies with the efficacy of toxins to fight cancer, with selected antibodies loaded with cytotoxic compounds that are transported into diseased cells where they unleash their effect.
The clinical importance of these findings lies in addressing the substantial unmet medical need in multiple myeloma patients who have relapsed or become refractory to existing treatments. Multiple myeloma remains a challenging cancer to treat, and new therapeutic approaches are critically needed to improve patient outcomes. The Phase I portion of the ongoing study is a dose-escalation trial designed to determine the optimal and safe dose level of HDP-101 in preparation for subsequent Phase II clinical evaluation.
For the oncology field, the success of HDP-101 could validate the use of Amanitin-based ADC technology as a new platform for cancer treatment development. The company has additional ATAC candidates in development, including HDP-102 for Non-Hodgkin Lymphoma, HDP-103 for metastatic castration-resistant prostate cancer, and HDP-104 targeting gastrointestinal tumors. A recording of the R&D webinar will be accessible via the press and investor section of the company website at www.heidelberg-pharma.com after the event.
