Heidelberg Pharma : Half-year financial report 2024

• First preliminary efficacy data from the clinical trial with HDP-101 in multiple myeloma published
• Presentation of preclinical and clinical data of the proprietary ADC technology platforms at the AACR meeting 2024
• Orphan drug designation for HDP-101 granted by the FDA
• Sale of a portion of future royalties for TLX250-CDx to HealthCare Royalty
• Professor Andreas Pahl takes over as Chief Executive Officer

HALF-YEAR FINANCIAL REPORT 2024

2 HEIDELBERG PHARMA | HALF-YEAR FINANCIAL REPORT 2024

KEY FIGURES

	H1 2024 1	H1 2023 1
	€ '000	€ '000
Earnings
Sales revenue	4,055	4,391
Other income	2,227	277
Operating expenses	(15,551)	(20,704)
of which research and development costs	(10,583)	(14,772)
Operating result	(9,269)	(16,036)
Earnings before tax	(8,665)	(15,774)
Comprehensive income	(8,665)	(15,951)
Net loss for the period	(8,665)	(15,951)
Earnings per share in €	(0.19)	(0.34)
Balance sheet at end of period
Total assets	71,974	77,965
Cash	42,619	57,379
Equity	41,163	50,891
Equity ratio2 in %	57.2	65.3
Cash flow statement
Cash flow from operating activities	(16,924)	(18,153)
Cash flow from investing activities	(84)	(788)
Cash flow from financing activities	16,144	(5,008)
Employees (number)
Employees as of the end of the period (headcount) 3	110	113
Employees as of the end of the period (full-time equivalents) 3	97	103

1The reporting period begins on 1 December and ends on 31 May.

2Equity/total assets

3Including members of the Executive Management Board

Rounding of exact figures may result in differences in all tables of this report.

LETTER TO THE SHAREHOLDERS

Dear Ladies and Gentlemen, Dear Shareholders,

The last few months have been quite eventful. In March of this year, we signed a forward-looking agreement with HealthCare Royalty to sell part of the royalties from the portfolio candidate TLX250-CDx, which we developed up to the first Phase III clinical trial and out-licensed to our Australian partner Telix in 2017.

Telix conducted a second Phase III trial, which generated positive results. Based on these, Telix started a rolling Biologics License Application (BLA) submission to the US Food and Drug Administration (FDA) for the candidate TLX250-CDx in December 2023 for detection of clear cell renal cell carcinoma. Our partner announced in early June that it had completed the BLA submission. Telix hopes to achieve regulatory approval on the US market by the end of the year.

This agreement makes Heidelberg Pharma eligible for both milestone payments and royalties. We have now sold part of these future royalties to HealthCare Royalty. The agreed upfront payment of USD 25 million has already been collected. We expect to receive a further USD 75 million upon FDA approval of TLX250-CDx. A priority for us was to agree on a maximum cumulative repayable amount with HealthCare Royalty. As soon as this threshold has been reached, royalty payments will revert to Heidelberg Pharma. This means that we are already benefiting from the candidate's success and will continue to do so in the future.

On the scientific side, we were delighted to be able to release initial safety and preliminary efficacy data from the Phase I clinical trial with our ATAC development candidate HDP-101 back in December. Three patients from Cohort 5 were observed to be in partial remission. During treatment in Cohort 5, a temporary drop in thrombocyte count occurred, although this normalized within a few days. As a result, we will optimize the dosing regimen for Cohort 6.

We received some good news in March. The FDA has granted Orphan Drug Designation for the treatment of multiple myeloma to HDP-101. This provides further validation of the potential benefit of our Amanitin-based ADC candidate in this indication.

In the second half of the year, we will focus on recruiting patients for the clinical trial with HDP-101 and on submitting the trial application for the ATAC successor candidate HDP-102.

Based on current financial planning, the Company's financing is secured until mid-2025. Taking into account a further expected payment of USD 75.0 million from HealthCare Royalty upon the approval of TLX250-CDx, we assume based on the current medium-term planning that funding will be available until the end of 2026.

We are very optimistic that we will see further positive development of our clinical trial and that study participants will benefit from the therapy. Encouraging data, a dynamically developing pipeline and the achievement of some expected milestones should all have a positive impact on our valuation. We thank you for your trust and support.

Ladenburg, 11 July 2024

Yours sincerely,

Professor Andreas Pahl

Chief Executive Officer

2 HEIDELBERG PHARMA | HALF-YEAR FINANCIAL REPORT 2024

INTERIM MANAGEMENT REPORT

Reporting period from 1 December 2023 to 31 May 2024

Introduction

Heidelberg Pharma is active in biopharmaceutical drug development, specializing in oncology. The company researches, develops and produces Antibody Drug Conjugates (ADCs), which combine the high affinity and specificity of antibodies with the efficacy of toxins. The focus of activities is on the patented and proprietary­ ATAC technology, which is based on the fungal toxin Amanitin and utilizes the biological mechanism of action of this toxin as a new therapeutic principle in cancer medicine. To Heidelberg Pharma's knowledge, it is the first company to develop the active ingredient Amanitin for cancer therapies. The ATAC technology platform is used for the development of proprietary therapeutic antibody-Amanitin conjugates as well as in collaborations with external partners.

In addition to the toxin Amanitin, which is known from the death cap mushroom, the company has been using other active substances such as the topoisomerase I inhibitor Exatecan or immunostimulatory active substances such as the toll-like receptor TLR7 since financial year 2023, thus supplementing the proprietary ATAC technology with additional ADC technologies ("toolbox") in order to develop the best possible ADCs for other target antigens and areas of application.

The most advanced development candidate HDP-101 is an Amanitin-based ADC and uses an antibody targeting the molecule BCMA on myeloma cells. HDP-101 is in Phase I clinical development for the treatment of patients with multiple myeloma (MM). Further ATAC candidates are being developed against various target molecules such as CD37, PSMA or GCC in the indications of non-Hodgkin's lymphoma, metastatic castration -resistant prostate cancer or gastrointestinal tumors such as colorectal cancer.

Key events in the first six months

HDP-101(BCMA-ATAC) development program

The ATAC candidate HDP-101 is currently in a Phase I/IIa clinical trial for the treatment of relapsed or refractory multiple myeloma.

The first five patient cohorts and dose levels have been completed. The first four patient cohorts proved to be safe and well tolerated. Since September 2023, patients in the 5th cohort have been treated with a dose of 100 µg/kg HDP-101. After the first administration of HDP-101, all patients experienced a short-term reduction in platelet count, which completely normalized after a few days and was clinically inconspicuous.

To mitigate this transient effect, the clinical team has adjusted and optimized the medication regimen. Cohort 6 will consist of three arms, with at least three patients enrolled in each arm. In consultation with the clinical investigators, the dose will be 90 µg/kg in order to test these three arms with as little risk to the patients as possible.

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Patients in Arm A will be treated with a single dose of HDP-101 on day 1 of each 21-day cycle following pre-medication. Arm B will receive a weekly dose of HDP-101, which means that the dose will be split and patients will be treated proportionally on days 1, 8 and 15 of each cycle. Arm C receives a partial dose of HDP­ -101 on days 1 and 8 of the first cycle and then a single dose on day 1 of each of the following 21-day cycles.

It is planned to continue further cohorts with the most promising dosage forms from cohort 6 and an increase in the dose.

The relevant authorities approved the listed protocol adjustments and the recruitment of the 6th cohort was prepared. First patients are currently being screened.

Fortunately, in cohort 5, three of the five patients treated with 100 µg/kg showed biological efficacy and an objective improvement in disease was detectable ("partial remission"). One of these patients is currently showing a further improvement in the course of the disease ("very good partial response"; VGPR).

One study participant from the third cohort received a total of 18 doses of HDP-101 without long-term side effects and showed stable disease progression over 15 months. A few weeks ago, progression of the disease was detected in this patient and treatment had to be discontinued.

New preclinical data of the ATAC technology platform presented at the AACR 2024 Annual Meeting

Heidelberg Pharma presented clinical and preclinical results of its ADC technologies at the American Association for Cancer Research (AACR) 2024 Annual Meeting in April. Initial safety and preliminary efficacy data from the Phase I clinical trial with the ATAC candidate HDP-101 were shown as well as preclinical data on the ATAC candidate HDP-102, an Amanitin-based ADC directed against the target molecule CD37. HDP-102 has shown excellent anti-tumor efficacy in in vivo studies after single administration. Initial preclinical studies show good tolerability, suggesting that HDP-102 represents a potential new treatment option for patients with non-Hodgkin's lymphoma (NHL).

Another poster showed that ADC binding independent of the target antigen (off-target tox mechanisms) is responsible, for example, for the premature release of the transported cytotoxins and can thus cause side effects.

In the presented study, the off-target toxic mechanisms of Amanitin-based ADCs (ATACs) were deciphered. The data show that liver toxicity is caused by non-specific uptake of the ATACs into liver cells. By substituting two amino acids in the antibody (LALA mutation), which are responsible for the non-specific binding of ATACs, the off-target toxicity could be reduced. This significantly increases the tolerability of ATACs, while the antitumor efficacy is not affected, resulting in an improved therapeutic window of ATACs.

4 HEIDELBERG PHARMA | HALF-YEAR FINANCIAL REPORT 2024

In addition, scientists from Heidelberg Pharma presented the first preclinical data from the new HDP-201 project, an exatecan-based ADC.

The posters are available on the company's website.1

In April, Heidelberg Pharma hosted its first R&D webinar with key opinion leaders (KOLs) in the ADC field. In addition to presentations on the technology platform by the management team, preclinical data were presented and interpreted by Rakesh Dixit, CEO of Bionavigen, Gaithersburg, USA, and clinical data from the study with HDP-101 by Jonathan Kaufman, MD, Associate Professor of Hematology & Medical Oncology, Emory University School of Medicine, Atlanta, USA.

The event provided furthermore information on the other ADC platform technologies and the therapeutic product pipeline.

HDP-101 receives orphan drug designation from the FDA

At the end of March, Heidelberg Pharma announced that the US Food and Drug Administration (FDA) had granted orphan drug designation (ODD) to the ATAC candidate HDP-101. Orphan drug designation is granted to a drug or biological product intended for the prevention, diagnosis or treatment of rare diseases affecting fewer than 200,000 people in the United States. The status provides significant incentives to encourage development of the drug, including tax credits for qualified clinical trials, prescription drug fee waivers, and a potential seven years of market exclusivity after FDA approval.

Agreement concluded on the partial sale of license fees to HealthCare Royalty

In early March 2024, Heidelberg Pharma signed an agreement with HealthCare Royalty, Delaware, USA, (HCRx) for the sale of a portion of future royalties from global sales of TLX250-CDx. Heidelberg Pharma received a non-refundable upfront payment of USD 25 million and is also entitled to receive up to an additional USD 90 million from the sale of royalties if defined milestones are reached. Of this amount, USD 75 million will be due upon approval of TLX250-CDx by the FDA. After HCRx has received a maximum cumulative amount, the royalties revert to Heidelberg Pharma, and HCRx receives a low single-digit percentage of Heidelberg­ Pharma's royalties.

TLX250-CDx is a radiolabeled form of the antibody girentuximab, which binds to the tumor-specific antigen CAIX on clear cell renal cell carcinoma. Heidelberg Pharma developed the antibody up to a first completed Phase III clinical trial before out-licensing it to Telix Pharmaceuticals Limited, a company based in Mel- bourne, Australia, (Telix) in 2017. Telix completed the submission of the marketing authorization application to the FDA in early June 2024 and expects to obtain marketing authorization for the product by the end of 2024. An accelerated review ("priority review") was also applied for in parallel.

1 https://heidelberg-pharma.com/de/forschung-entwicklung/wissenschaftliche-poster

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Professor Andreas Pahl becomes Chief Executive Officer

The Supervisory Board appointed Professor Andreas Pahl as the new Chief Executive Officer effective 1 Feb- ruary 2024 after Dr. Jan Schmidt-Brand,long-standing Chief Executive Officer of Heidelberg Pharma AG and Managing Director of the subsidiary Heidelberg Pharma Research GmbH, stepped down on 31 January 2024 upon reaching retirement age. Professor Pahl has simultaneously assumed the role of Managing Director of the subsidiary. Professor Pahl has been Head of Research & Development at Heidelberg Pharma since 2012 and has been a member of the Executive Management Board since 2016. He holds a doctorate in chemistry and has more than 25 years of experience in the pharmaceutical industry as well as in research and teaching.

Research and development activities

ADC technology (antibody drug conjugates)

Heidelberg Pharma is developing technology platforms for antibody drug conjugates (ADCs). ADCs that combine the specificity of antibodies with the efficacy of toxins to fight cancer. The core of this technology is to offer new approaches to antitumor therapy by exploiting a previously unused biological mode of action for cancer treatment.

Heidelberg Pharma is the first company to use the fungal toxin Amanitin for cancer therapy. The company uses the toxin's biological mechanism of action with its innovative ATAC technology as a new therapeutic principle. The toxin is a member of the amatoxin group of natural poisons, which occur in the death cap mushroom (Amanita phalloides), among others. By inhibiting RNA polymerase II, Amanitin triggers natural cell death (apoptosis). This novel principle in cancer therapy offers the possibility of breaking through drug resistance and destroying dormant tumor cells, which could produce major clinical advances.

Amanitin's mode of action also has the potential to be particularly effective against tumors that have changed due to so-called 17p deletion to bypass a special mechanism of cell protection. This change is found in most cancers, and especially in very aggressive forms. Tumors with 17p deletion could be a particularly effective target for the treatment with ATACs.

The most advanced product candidate HDP-101 is a BCMA-ATAC for the indication multiple myeloma, which is currently in clinical development.

In addition to Amanitin, the company has been using other active substances such as the topoisomerase I inhibitor Exatecan or immunostimulatory active substances such as the Toll-like receptor TLR7 since financial year 2023, thereby supplementing the proprietary ATAC technology with additional ADC technologies ("toolbox") in order to develop the best possible ADCs for other target antigens and areas of application.

On the one hand, the business model focuses on building up the company's own product pipeline. In this pillar, proprietary ADC molecules based on licensed or self-generated antibodies are produced, tested as R&D candidates and further developed in-house.

6 HEIDELBERG PHARMA | HALF-YEAR FINANCIAL REPORT 2024

On the other hand, the hybrid business model includes a business-to-business activity in which the drug- linker technologies developed by Heidelberg Pharma are to be licensed by pharmaceutical and biotech companies in order to make their antibodies more therapeutically effective against tumor diseases. Within this framework and integrated into license agreements, Heidelberg Pharma offers the cooperation partners not only licensing rights but also technological support in the production and purification of the conjugates, in the production and supply of the active ingredient and in selected preclinical studies. These ADC col­ laborations are intended to generate continuous sales and license payments.

The in-house developments and the intended out-licensing are each carried out exclusively for a specific antigen (biological target protein). As there are a large number of tumor-specific antigens, it is possible to develop our own product candidates and cooperate in parallel with various pharmaceutical and biotech- nology companies. The resulting development candidates can be developed into different products for different indications.

Proprietary ATAC pipeline

Project HDP-101(BCMA-ATAC)

HDP-101 is a BCMA-ATAC that will be tested in the indication multiple myeloma. BCMA (B-cell maturation antigen) is a surface protein that is highly expressed in multiple myeloma cells, to which BCMA antibodies specifically bind, bringing the Amanitin to the cancer cell.

In preclinical models, HDP-101 showed excellent anti-tumor activity including complete tumor remission, and very good tolerability in relation to the effective doses. Finally, the efficacy of HDP-101 was demonstrated for the first time ex vivo on human multiple myeloma tumor cells from patients.

Multiple myeloma is a cancer affecting bone marrow and the second most common hematologic cancer;­ it represents a major unmet medical need where new, more effective therapies are urgently required. HDP­ -101 also has potential in further hematologic indications.

The candidate is being evaluated since February 2022 in a Phase I/IIa clinical trial for treatment of relapsed or refractory multiple myeloma. The first part of this trial is a Phase I dose escalation study to determine a safe and optimal dosage of HDP-101 for the Phase IIa part of the study.

Project HDP-102(CD37-ATAC)

HDP-102 is an ATAC targeting CD37 that is overexpressed on B-cell lymphoma cells. HDP-102 will be developed for specific indications of non-Hodgkin lymphoma (NHL). Preclinical studies have shown that this development candidate has a very large therapeutic window. This means that the distance between its therapeutic dose and a dose that leads to an unacceptable toxic effect is as large as possible. At the AACR Annual Meeting in April 2024, several Heidelberg Pharma scientists presented data showing excellent anti-tumor efficacy after a single dose in in vivo studies as well as good tolerability of HDP-102.

The production of the clinical investigational medicinal products in accordance with GMP (Good Manufacturing Practice) standards is proceeding according to plan and has largely been completed. In addition, further preclinical and toxicological studies have been completed and the data package required to initiate the first clinical trial on humans is expected to be completed in the fourth quarter of this year and submitted to the regulatory authority in a European country as a first step.

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Project HDP-103(PSMA-ATAC)

HDP-103 will be developed for the treatment of metastatic castration-resistant prostate cancer (mCRPC). The antibody used binds to PSMA, a surface antigen that is overexpressed on prostate cancer cells. This is a promising target for the ATAC technology because PSMA shows only very limited expression in normal tis- sue. Preclinical studies on in vitro and in vivo efficacy, tolerability and pharmacokinetics have shown that HDP-103 has a promising therapeutic window. This is confirmed by the fact that at 60% there is a very high prevalence of a 17p deletion in mCRPC. The increased sensitivity of prostate cancer cells with a 17p deletion has already been preclinically validated.2 Since tumor cells with a 17p deletion are particularly sensitive to Amanitin, PSMA-ATACs might be particularly suitable for treating mCRPC.

In recent months, production of HDP-103 under GMP conditions was completed as planned. The preclinical and toxicology studies with HDP-103 have now been largely completed. A clinical study to investigate tolerability and efficacy is currently being planned and the clinical team is preparing the study protocol in the coming months.

Heidelberg Pharma plans to submit a trial application for HDP-103 to the regulatory authorities in 2025.

Project HDP-104(GCC-ATAC)

The ATAC candidate HDP-104 targets guanylyl cyclase C or GCC, a receptor that is expressed on the surface of intestinal cells and cancer cells in various gastrointestinal tumors. The candidate is currently not being further developed at Heidelberg Pharma. The focus is on the HDP­-201 ­project instead, which is being worked on in the same indication and with the same antibody but a different payload.

Project HDP-201

Since fall 2023, the company has been developing further ADC projects with other loading agents. The first candidate with a toxin other than Amanitin is HDP-201, an exatecan-based ADC. Exatecan is a topoisomer- ase I inhibitor that has proven itself in cancer therapy and is used in two already approved ADCs. It differs in its mode of action from that of Amanitin and thus expands the company's range of active ingredients.

HDP-201, targets guanylyl cyclase-C (GCC), a receptor that is expressed on the surface of intestinal cells and cancer cells in various gastrointestinal tumors. The company presented preclinical results to date at AACR 2024, where they met with a very large and very positive response. The results show that the tolerability and efficacy of HDP-201 is at least comparable to already approved exatecan ADCs.

The target protein to which the antibody used binds is overexpressed in over 95% of colorectal cancers and around 65% of esophageal and gastric tumors as well as pancreatic tumors. Since the GCC antibody has already been produced for the HDP-104 program, sufficient quantities of the antibody are available to supply two ADC projects. The short-term availability of the antibody shortened the research time and allowed Heidelberg Pharma to quickly start the development process of HDP-201.In vitro/in vivo tests and initial preclinical trials have now been completed.

2 https://www.nature.com/articles/s41467-018-06811-z

8 HEIDELBERG PHARMA | HALF-YEAR FINANCIAL REPORT 2024

ATAC collaborations

Collaboration with Takeda

Back in June 2017, Heidelberg Pharma signed an exclusive research agreement with Takeda Oncology, Cam- bridge, MA, USA, (Takeda), the subject of which is several targets for joint development of ADCs using the compound Amanitin. Under the terms of the exclusive research agreement, Heidelberg Pharma produced several ATACs using antibodies from Takeda's proprietary portfolio. As a result of this work, Takeda acquired an exclusive license in September 2022 to commercially develop an ATAC with a selected target. Takeda is responsible for further preclinical and clinical development, as well as potential commercialization, of the licensed product candidate. In August 2023, the Company's partner Takeda reached a development milestone by starting a GLP (Good Laboratory Practice) toxicology study.

Clinical portfolio

TLX250-CDx - diagnostic antibody

TLX250-CDx is a radiolabeled form of the antibody girentuximab, which binds to the tumor-specific antigen CAIX on clear cell renal cell carcinoma (ccRCC) and possibly other tumor types. Accumulation of this antibody in tumor tissue can be visualized by positron emission tomography (PET) scans. This could fundamentally change therapy planning for renal cancer patients and avoid potentially unnecessary surgery. The diagnostic agent may also prove suitable for monitoring response to treatment, detecting metastases and for diagnosing other kinds of tumors.

The antibody was developed at Heidelberg Pharma AG up to a first Phase III trial and outlicensed to the Aus- tralian company Telix in 2017.

Telix had conducted a second Phase III trial and, based on these positive Phase III results, began filing a rolling submission in the USA in December 2023 for the candidate TLX250-CDx for the identification of clear cell renal cell carcinoma. The partner announced at the beginning of June that the submission of the documents to the FDA had been completed.

As a Breakthrough Therapy Designation product candidate, TLX250-CDx has been granted a rolling review process that allows for phased submission and review of required modules on a pre-agreed schedule with the FDA. Telix has also applied for priority review. Telix plans a potential marketing authorization in the US by the end of this year.

Parallel to the preparations for market approval, Telix has introduced an "expanded access program" in the USA and a "named patient program" in Europe to give patients access to TLX250-CDx even before approval. Patients have already been accepted into this program in some European countries and in the USA.

Telix is conducting further clinical trials to potentially expand the indication of TLX250-CDx beyond kidney cancer, including triple-negative metastatic breast cancer (TNBC) and bladder cancer.

Heidelberg Pharma is entitled to milestone payments and royalties in the double-digit percentage range if the product receives marketing authorization. In March 2024, a portion of the future royalties from global sales of TLX250-CDx was sold to HealthCare Royalty.