TLX Telix Pharmaceuticals Ltd

First Patient Dosed in Study of Targeted Alpha Therapy Candidate for Bladder Cancer
Telix Pharmaceuticals Limited (ASX: TLX, Telix, the Company) and Nantes-based ATONCO S.A.S. (‘ATONCO’) today announce that a first patient has been dosed in a Phase I study of TLX250-CDx in patients with non-muscle-invasive bladder cancer (NMIBC) at the Institut de Cancérologie de l’Ouest (ICO) in St Herblain, France.

The objective of ‘PERTINENCE1’ an investigator-led, open-label, proof of concept study, is to evaluate safety, biodistribution and dosing properties of TLX250-CDx (89Zr-DFO-girentuximab) in patients with NMIBC. The PERTINENCE study builds on the Telix and ATONCO licence and development agreement announced in December 2019,2 and will be led by Dr. Caroline Rousseau at ICO. It will recruit 6 patients over 12 months, with a successful outcome leading to therapeutic studies with astatine-211 (211At) for targeted alpha therapy (TAT). TLX250-CDx (girentuximab) targets carbonic anhydrase IX (CA9), a receptor that is overexpressed in many solid tumours, including urologic malignancies.

The study is aligned with Telix’s focus on the development of alpha therapy in future pipeline expansion and its strategy to pursue additional indications for the CA9 target, a core pipeline asset, which is currently being evaluated in clear cell renal cell carcinoma (ccRCC) in the Company’s Phase III imaging study (ZIRCON) and Phase II therapeutic studies (STARLITE 1 and 2).

PERTINENCE is the third in a comprehensive series of studies investigating CA9 as a target for molecularly targeted radiation (MTR) in other tumour types as well as providing a pathway to evaluate TLX250 with an alpha emitting isotope for the first time in humans.

Alpha emitters have the potential to deliver very high amounts of energy to cancer tissue whilst the short path length can decrease the risk of damage to surrounding healthy cells, increasing the selectivity and potency of the radiation treatment. Alpha emitters have the potential to be complementary to beta-emitters in different stages of disease.

The two other studies evaluating CA9 (ZiP-UP3 and OPALESCENCE4) have been initiated for urothelial carcinoma or bladder cancer, and triple negative breast cancer, respectively, with other collaborative studies in development for ovarian, colorectal, head and neck, lung, and pancreatic cancers.

Principal Investigator for the PERTINENCE study, sponsored by ICO, Dr. Caroline Rousseau said, “CA9 is a very interesting target that is highly expressed in many hypoxic solid tumors. This study builds on the clinical work we are already doing with CA9 in the OPALESCENCE study and will help us generate a better understanding of the imaging properties of TLX250-CDx in NMIBC as a precursor to studying the role of girentuximab as a therapy with an alpha emitting radioisotope.”

ATONCO CEO, Sylvain Fanier continued, “We are excited to extend our partnership with Telix, one of the most respected companies in nuclear medicine, and to develop an innovative MTR solution with our local academic and industry partners in Nantes, to improve therapeutic options for patients suffering from NMIBC.”

Telix Chief Medical Officer, Dr Colin Hayward added, “We are pleased to further our collaboration with ATONCO to explore girentuximab as a base for therapy with the alpha-emitting radioisotope astatine-211 (211At) as well as extending and accelerating development options to numerous cancer types where there is unmet medical need. 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.”

_______________1 Clinicaltrials.gov identifier: NCT048977632 ASX disclosure 16/12/19.3 ASX disclosure 23/06/21.4 Media release 05/10/21.

About Bladder Cancer

Bladder cancer is the sixth most commonly occurring cancer in men, and the tenth most common cancer overall worldwide.5 In 2020, 573,278 people worldwide were diagnosed with bladder cancer and 212,536 people died from their disease.6 Non-muscle-invasive bladder cancer (NMIBC) is found in the tissue that lines the inner surface of the bladder and is responsible for approximately 75–85% of newly diagnosed bladder cancers.7

About ATONCO

ATONCO is a clinical-stage radiopharmaceutical company developing innovative radiopharmaceuticals using astatine-211 (211At), an alpha-emitting radionuclide for the treatment of cancer. ATONCO, founded in 2019, built with an experienced and passionate team, holds an exclusive worldwide licence to use Telix’s girentuximab (TLX250) for radiolabelling with 211At for treatment of NMIBC. ATONCO, based on disruptive and innovative alpha-immunotherapy, meets two goals: clinical indications with real unmet need and rapidly accessible tumor targets, suited to the short half-life of astatine-211 (7.2h) and with a small size suited to the very short path length of emitted alpha particles. ATONCO is a private company registered in Nantes-Saint Herblain, France. For more information contact: info@atonco-pharma.com

About TLX250-CDx

TLX250-CDx (89Zr-DFO-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 carbonic anhydrase IX (CA9), a cell surface target that is highly expressed in several human cancers including renal, lung and oesophageal cancers. In July 2020, the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy (BT) designation8 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, Switzerland 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.

_______________5 World Cancer Research Fund (WCRF).6 Globocan 2021.7 Somuncu et al. Nature. 2020.8 ASX disclosure 01/07/20.

Telix Media Contact

Dr. Stewart HolmstromTelix Pharmaceuticals LimitedDirector Corporate CommunicationsEmail: stewart.holmstrom@telixpharma.com

Important Information

This announcement does not constitute an offer to sell, or a solicitation of an offer to buy, securities in the United States, or in any other jurisdiction in which such an offer would be illegal. The securities referred to herein have not been and will not be registered under the United States Securities Act of 1933 (the “U.S. Securities Act”), or under the securities laws of any state or other jurisdiction of the United States and may not be offered or sold within the United States, unless the securities have been registered under the U.S. Securities Act or an exemption from the registration requirements of the U.S. Securities Act is available. None of the technologies or products described in this document have received a marketing authorisation in any jurisdiction. This announcement has been authorised for release by Dr. Christian Behrenbruch, Managing Director and Chief Executive Officer. The Telix Pharmaceuticals name and logo are trademarks of Telix Pharmaceuticals Limited and its affiliates (all rights reserved)