Heidelberg Pharma’s Lead ADC Candidate HDP-101 Granted Fast Track Designation by US FDA for the Treatment of Multiple Myeloma

EQS-News: Heidelberg Pharma AG / Key word(s): Miscellaneous Heidelberg Pharma’s Lead ADC Candidate HDP-101 Granted Fast Track Designation by US FDA for the Treatment of Multiple Myeloma 23.10.2025 / 07:57 CET/CEST The issuer is solely responsible for the content of this announcement. PRESS RELEASE

Heidelberg Pharma’s Lead ADC Candidate HDP-101 Granted Fast Track Designation by US FDA for the Treatment of Multiple Myeloma

• Recognizes the potential of HDP-101 to address a serious or life-threatening condition with high unmet medical needs
• Enables more frequent engagement with FDA and eligibility for rolling review to support expedited development and review

Ladenburg, Germany, 23 October 2025 – Heidelberg Pharma AG (FSE: HPHA), a clinical-stage biotech company developing innovative Antibody Drug Conjugates (ADCs), today announced that HDP-101 (INN: pamlectabart tismanitin), the Company’s lead Amanitin-based ADC candidate, has been granted Fast Track Designation by the US Food and Drug Administration (FDA).

This designation was supported by nonclinical data as well as clinical data from the ongoing Phase I/IIa study with HDP-101 (INN: pamlectabart tismanitin), evaluating the safety and antitumor activity of the candidate in patients with relapsed or refractory multiple myeloma.

Professor Andreas Pahl, Chief Executive Officer of Heidelberg Pharma, commented: “The FDA’s granting of Fast Track Designation is fantastic news for Heidelberg Pharma and underscores the potential of HDP-101 for the treatment of severely ill and heavily pretreated patients. This designation will support our efforts to advance our lead ADC candidate efficiently toward patients with multiple myeloma who continue to face significant unmet medical needs.”

Fast Track Designation is intended to accelerate the development and review of therapies that address serious or life-threatening conditions with unmet medical needs. This status enables more frequent engagement with the FDA, allows Rolling Review of the Biologics License Application (BLA), and may provide eligibility for Priority Review or Accelerated Approval.