Heidelberg Pharma AG (FSE: HPHA) will present new clinical data from its Phase I/IIa study of lead candidate pamlectabart tismanitin (HDP-101) in an oral session and from its second candidate HDP-102 in a poster session at the 68th Annual Meeting of the American Society of Hematology (ASH), taking place in New Orleans from 12 to 15 December 2026. The disclosures are significant because they provide the first clinical validation of the company’s Amanitin-based ATAC technology in two distinct blood cancers and clarify the path forward for its lead program.
For HDP-101, an anti-BCMA antibody-drug conjugate for relapsed or refractory multiple myeloma (RRMM), the oral presentation will detail the selection of the recommended Phase 2 dose (RP2D) and preliminary antitumor activity. The Phase I dose-escalation portion, which included ten patient cohorts, was completed in April 2026, and the RP2D was determined. The Phase IIa expansion is progressing as planned. According to the company, pamlectabart tismanitin demonstrated consistent clinical activity with a favorable safety profile in heavily pretreated RRMM patients, supporting its potential as a novel payload BCMA-targeted ADC therapy. The oral presentation (publication number 270) will be given by Professor Marc-Steffen Raab, MD, on Saturday, 12 December 2026, from 03:15 to 03:30 pm CDT in Room La Nouvelle A-B at the Ernest N. Morial Convention Center. The abstract is available in the ASH® ANNUAL PROGRAM.
For HDP-102, a first-in-class CD37-targeted Amanitin-based ADC, the poster presentation will report translational activity and early safety and efficacy in relapsed or refractory B-cell malignancies. In the first cohort, three patients were treated with 40 µg/kg; the treatment was well tolerated, and initial signs of biological activity were observed at the very low dose. Two patients showed stabilization of disease with regression and reduction of lymph nodes. The safety committee recommended increasing the dose to 65 µg/kg for the second cohort. However, in line with Heidelberg Pharma’s strategic decision from September 2025 to discontinue the study, the company is exploring partnership opportunities to support the continuation of the program. The poster (publication number 3717) will be presented by Dr. Irina Mocanu, MD, on Sunday, 13 December 2026, from 06:00 to 08:00 pm CDT in Hall F, and the abstract is accessible via the ASH® ANNUAL PROGRAM.
The news matters because it offers the most mature clinical evidence to date for the company’s ATAC platform, which uses a toxin derived from the green death cap mushroom. HDP-101 has received Orphan Drug Designation and Fast Track Designation from the FDA, and the RP2D selection marks a critical step toward later-stage trials in multiple myeloma, a disease with high unmet need. Meanwhile, the HDP-102 data, though early, show biological activity at a very low dose, suggesting the CD37-targeted approach may warrant further development through a partner. The company’s pipeline also includes HDP-103 for metastatic castration-resistant prostate cancer and HDP-104 for gastrointestinal tumors, both of which have completed preclinical development and are available for partnering. More information is available at http://www.heidelberg-pharma.com/.
