First Patient Dosed in Phase II Study of TLX250-CDx in Triple-Negative Breast Cancer

Potential Indication Expansion for Telix’s Core Kidney Cancer Theranostic Program

MELBOURNE, Australia and LIÈGE, Belgium, Oct. 05, 2021 (GLOBE NEWSWIRE) -- Telix Pharmaceuticals Limited (ASX: TLX, ‘Telix’, the ‘Company’) today announces that a first patient has been dosed in a Phase II study of TLX250-CDx (⁸⁹Zr-DFO-girentuximab) in patients with triple-negative breast cancer (TNBC) at the Institut de Cancérologie de l’Ouest (ICO) in St Herblain, France.

‘OPALESCENCE’, an investigator-led study being undertaken by Dr. Caroline Rousseau at ICO, aims to evaluate how carbonic anhydrase IX (CA9) imaging with positron emission tomography (PET) can be utilised for diagnosis and staging of TNBC and to develop a deeper understanding of CA9 as a potential therapeutic target in this patient population.¹ The study will enrol 12 patients. TNBC has a poorer prognosis than other breast cancer subtypes and is characterised by its aggressive behaviour and distinct patterns of metastasis. There is a major unmet need due to the lack of targeted therapies for TNBC.

CA9 is a transmembrane protein that is highly over-expressed in clear cell renal cancer (ccRCC) as well as a number of other different cancer types, making it an attractive potential target for both new imaging and therapeutic modalities. Telix’s core CA9 program is focused on ccRCC, the most common form of kidney cancer, and is the subject of the ZIRCON Phase III (imaging) and STARLITE Phase II (therapy) studies. OPALESCENCE is the second in a comprehensive series of studies that will evaluate CA9 expression in cancers other than ccRCC, supporting Telix’s goal to rapidly expand the CA9 program into other indications. A study targeting CA9 in urothelial carcinoma or bladder cancer is underway,² with other collaborations being developed for ovarian, colorectal, head and neck, lung, and pancreatic cancers.

Telix Chief Medical Officer, Dr. Colin Hayward stated, "Telix is very pleased to see a first patient dosed in this important study of TLX250-CDx in TNBC, an aggressive breast cancer subtype that is poorly served by current tracers. Should the targeting properties of this PET/CT imaging tracer be established in TNBC, our intention is to broaden future applications for Telix’s lutetium-177 and actinium-225 based CA9 therapies. We would like to express our gratitude to Dr. Caroline Rousseau and her clinical team at ICO, as well as the patients that will contribute to this ground-breaking study.”

Principal Investigator for the OPALESCENCE study, Dr. Caroline Rousseau stated, "Theranostic approaches to diagnosis and treatment are transforming prostate cancer. Triple negative breast cancer has a poor prognosis, so the potential to identify new targets with potential theranostic approaches for these patients is very exciting.”

About Triple-Negative Breast Cancer

Breast Cancer is the most commonly occurring cancer in women and the second most common cancer overall.³ In 2020, over 2.2 million women were diagnosed with breast cancer and 685,000 died from their disease.⁴ Triple-negative breast cancer accounts for about 10-15% of all breast cancers with the term triple-negative referring to the fact that the cancer cells do not have any of the three markers commonly found on breast cancer cells – the oestrogen and progesterone receptors, and HER2 protein. TNBCs differ from other types of invasive breast cancer in that they grow and spread faster, have limited treatment options, and a poorer prognosis.⁵

About TLX250-CDx

TLX250-CDx (⁸⁹Zr-girentuximab) is being developed by Telix for the purpose of determining whether "indeterminate renal masses”, typically identified based on CT or MRI imaging, are either clear cell renal cell cancer (ccRCC) or non-ccRCC, using Positron Emission Tomography (PET) imaging. Girentuximab is a monoclonal antibody that targets CA9, a cell surface target that is highly expressed in several human cancers including renal, lung and oesophageal cancers. In June 2020, the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy (BT) designation⁶ for TLX250-CDx, reflecting the significant unmet clinical need to improve the diagnosis and staging of ccRCC, the most common and aggressive form of kidney cancer.

About Telix Pharmaceuticals Limited

Telix is a biopharmaceutical company focused on the development of diagnostic and therapeutic products using Molecularly Targeted Radiation (MTR). Telix is headquartered in Melbourne, Australia with international operations in Belgium, Japan, and the United States. Telix is developing a portfolio of clinical-stage products that address significant unmet medical need in oncology and rare diseases. Telix is listed on the Australian Securities Exchange (ASX: TLX). For more information visit www.telixpharma.com and follow Telix on Twitter (@TelixPharma) and LinkedIn.

Telix’s lead investigational product, Illuccix^® (TLX591-CDx) for prostate cancer imaging, has been accepted for filing by the U.S. FDA,⁷ and is under priority evaluation by the Australian Therapeutic Goods Administration (TGA).⁸ Telix is also progressing marketing authorisation applications for Illuccix^® in the European Union⁹ and Canada.¹⁰ None of Telix’s products have received a marketing authorisation in any jurisdiction.

Telix Media Contact

Dr. Stewart Holmstrom
Telix Pharmaceuticals Limited
Director Corporate Communications
Email: stewart.holmstrom@telixpharma.com

¹ ClinicalTrials.Gov Identifier: NCT04758780.
² ASX disclosure 23/06/21.
³ World Cancer Research Fund (WCRF).
⁴ GLOBOCAN.
⁵ American Cancer Society.
⁶ ASX disclosure 1/07/20.
⁷ ASX disclosure 24/11/20.
⁸ ASX disclosure 14/04/21.
⁹ ASX disclosure 1/05/20.
¹⁰ ASX disclosure 16/12/20.