Heidelberg Pharma to Present New Clinical Data on Its ATAC Candidates at the ASH Annual Meeting 2026

LADENBURG, GERMANY - November 4, 2026 (NEWMEDIAWIRE) - Heidelberg Pharma AG (FSE: HPHA), a clinical stage company developing innovative Antibody Drug Conjugates (ADCs), will present new data from its Phase I/IIa clinical study with its lead Amanitin-based ADC candidate, pamlectabart tismanitin (HDP-101), in an oral presentation, as well as data from its second clinical candidate, HDP-102, during the poster abstract session of the 68th Annual Meeting of the American Society of Hematology (ASH), being held in New Orleans, USA, from 12 to 15 December 2026.

Details of the oral presentation (HDP-101):

Presentation title: First-in-human phase 1/2a study of pamlectabart tismanitin (HDP-101), an amanitin-based BCMA-targeting antibody-drug conjugate (ADC): Recommended phase 2 dose (RP2D) selection and preliminary antitumor activity in relapsed/refractory multiple myeloma (RRMM)

Pamlectabart tismanitin is an anti-BCMA antibody-Amanitin drug conjugate for the treatment of relapsed or refractory multiple myeloma (RRMM), a bone marrow cancer with a high unmet medical need. Phase I of the trial was a dose-escalation study to determine a dose level of the candidate for the Phase IIa expansion part of the study.

The Phase I part of the study included ten patient cohorts and was completed in April 2026, and the recommended dose for the Phase IIa expansion part (Recommended Phase 2 Dose; RP2D) was determined. The Phase IIa is progressing as planned.

Pamlectabart tismanitin demonstrated consistent clinical activity with a favorable safety profile in heavily pretreated RRMM patients supporting the potential of the candidate as a novel payload BCMA-targeted ADC therapy.

Details of the poster presentation (HDP-102):

Presentation title: HDP-102, a first-in-class CD37-targeted amanitin-based antibody-drug conjugate, demonstrates translational activity, favorable early safety and efficacy in relapsed/refractory (R/R) B-cell malignancies

HDP-102 is an ADC targeting CD37, which is overexpressed on B-cell lymphoma cells. Preclinical studies have shown excellent anti-tumor efficacy in in vivo studies as well as good tolerability. HDP-102 is intended to be developed for specific indications of non-Hodgkin lymphoma.

In 2025, Heidelberg Pharma announced the dosing of the first patient with HDP-102. Three patients were treated with 40 µg/kg in the first cohort. The treatment was well tolerated, and initial signs of biological activity have been observed already at the very low dose. Two patients showed stabilization of the disease with regression and reduction of lymph nodes. The safety committee recommended increasing the dose of HDP-102 to 65 µg/kg in cohort 2.

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.

About Heidelberg Pharma

Heidelberg Pharma is the first company to develop cancer therapies using Amanitin, a compound derived from the green death cap mushroom. The biological mechanism of action of the toxin represents a new therapeutic modality and is used as a compound in the Amanitin-based ADC technology, the so-called ATAC technology.

Lead candidate HDP-101 (INN: pamlectabart tismanitin) is a BCMA ATAC in clinical development for multiple myeloma. The candidate has been granted Orphan Drug Designation and Fast Track Designation from the FDA. A second ATAC candidate, HDP-102 is in clinical development stage in Non-Hodgkin Lymphoma. HDP-103 against metastatic castration-resistant prostate cancer and HDP-104 targeting gastrointestinal tumors such as colorectal cancer have completed preclinical development. These programs are available for partnering.

The company is based in Ladenburg, Germany, and is listed on the Frankfurt Stock Exchange: ISIN DE000A11QVV0 / WKN A11QVV / Symbol HPHA. More information is available at http://www.heidelberg-pharma.com/.

ATAC® is a registered trademark of Heidelberg Pharma Research GmbH.

Contact
Heidelberg Pharma AG
Sylvia Wimmer
Senior Director Corporate Communications
Tel.: +49 6203 1009 1004
E-mail: [email protected]
Wallstadter StraBe 59, 68526 Ladenburg

IR/PR-Support
MC Services AG
Katja Arnold (CIRO)
Managing Director & Partner
Tel.: +49 89 210 228-40
E-mail: [email protected]

This communication contains certain forward-looking statements relating to the Company's business, which can be identified by the use of forward-looking terminology such as "estimates", "believes", "expects", "may", "will" "should" "future", "potential" or similar expressions or by a general discussion of the Company's strategy, plans or intentions. Such forward-looking statements involve known and unknown risks, uncertainties and other factors, which may cause our actual results of operations, financial condition, performance, or achievements, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Given these uncertainties, prospective investors and partners are cautioned not to place undue reliance on such forward-looking statements. We disclaim any obligation to update any such forward-looking statements to reflect future events or developments.

View the original release on www.newmediawire.com

This contant was orignally distributed by NewMediaWire. Blockchain Registration, Verification & Enhancement provided by NewsRamp™. The source URL for this press release is Heidelberg Pharma to Present New Clinical Data on Its ATAC Candidates at the ASH Annual Meeting 2026.