Positive Topline Results from Phase II OPALESCENCE Study of TLX250-CDx in Triple Negative Breast Cancer Presented at SABCS

MELBOURNE, Australia, Dec. 7, 2023 /PRNewswire/ -- Telix Pharmaceuticals Limited (ASX: TLX, Telix, the Company) announces positive topline results from the Phase II OPALESCENCE investigator-initiated trial (IIT) of its carbonic anhydrase IX (CAIX)-targeting positron emission tomography (PET) imaging candidate, TLX250-CDx (⁸⁹Zr-DFO-girentuximab), in patients with triple negative breast cancer (TNBC). Results will be presented today at the 2023 San Antonio Breast Cancer Symposium^® (SABCS).

The pilot prospective study of twelve (12) metastatic patients demonstrated the expression of CAIX in TNBC and effective targeting with radiolabelled girentuximab:

• Expression and targeting of CAIX in lesions in the breast, skin, adrenal gland and brain was 100%
• Expression in nodes and bone was 88.0% and 91.9%, respectively
• TLX250-CDx was found to be safe and well tolerated by patients.

The OPALESCENCE study (ClinicalTrials.gov ID NCT04758780) was undertaken by Dr. Caroline Rousseau at the Institut de Cancérologie de l'Ouest (ICO) in St Herblain (France). The primary objective was to evaluate how CAIX-targeted imaging with PET can be utilised for the diagnosis and staging of TNBC and to develop a deeper understanding of CAIX as a potential therapeutic target in this patient population where there is significant unmet medical need. 

Results demonstrate the ability of TLX250-CDx to detect lesions that may resist chemotherapy and have a more aggressive profile resulting from hypoxia. The theranostic potential for girentuximab in this poor prognosis disease supports Telix's goal to expand its CAIX program into other indications beyond renal (kidney) cancer, including future applications for lutetium-177 (¹⁷⁷Lu) and actinium-225 (²²⁵Ac) based therapies. 

Principal Investigator for the OPALESCENCE study, Dr. Caroline Rousseau stated, "We are pleased to present encouraging topline results from this study of Telix's investigational CAIX targeting imaging agent in TNBC at SABCS, the largest and most prestigious scientific gathering on breast cancer research worldwide. Telix's imaging agent TLX250-CDx, which has shown high sensitivity and specificity in clinical trials for the detection of clear cell renal cell carcinoma,^[1] has now also exhibited potential utility in this most aggressive form of breast cancer, which is often metastatic and drug-resistant, with limited therapeutic options."

Dr. Christian Behrenbruch, Managing Director and Group CEO added, "Identifying new targets and treatment strategies for TNBC is a severe unmet need where only 20 percent of diagnosed patients are currently eligible for PD-L1-targeted therapies,^[2] the standard of care, with the remainder reliant on toxic chemotherapeutic regimens. This topline imaging data may demonstrate proof of concept for future therapeutic applications of radiolabelled girentuximab based on a "theranostic" approach. Telix looks forward to continuing to support the development of its CAIX-targeting antibody-based program for patients with TNBC and other solid tumours, with the ultimate aim to establish CAIX as pan-cancer therapeutic target."

About Triple Negative Breast Cancer 

Breast cancer is the most common 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 (TNBC) 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 the Institut de Cancérologie de l'Ouest (ICO)

ICO is a 1,400 professional strong not-for-profit center fighting against cancer. It welcomes close to 48,000 patients per year, and conducts the mission and service of a public hospital. Strengthened by its 4 missions – Prevention, Care, Research and Teaching – ICO offers broad, state-of-the-art expertise that is exclusively dedicated to cancerology. Advanced medicine at the service of patients: specialising in oncology, the ICO's provides patients with personalised, innovative and multidisciplinary care at every stage of treatment. From rapid diagnosis to surgery, chemotherapy and radiotherapy, care also extends to supportive care, which is highly developed at ICO.

The integration of care, research and innovation is integral to ICO. Research activities, which are a specific mission at ICO, are undertaken from concept all the way through to clinical trials. Research is conducted in all disciplines of cancerology: medical oncology, radiotherapy, surgery, anaesthesia, nuclear medicine, medical imagery, support care, and human sciences. Patients who are cared for at ICO receive privileged access to cutting edge clinical trials in cancerology. The mission of the Innovation Unit is to support innovation in oncology by assisting both internal and external project leaders from the initial idea to the operational implementation of the innovation.

Through its teaching mission and academic expertise, ICO contributes to the training of tomorrow's cancer professionals. For more information contact: promotionrc@ico.unicancer.fr 

About Telix Pharmaceuticals Limited

Telix is a biopharmaceutical company focused on the development and commercialisation of diagnostic and therapeutic radiopharmaceuticals and associated medical devices. Telix is headquartered in Melbourne, Australia with international operations in the United States, Europe (Belgium and Switzerland), and Japan. Telix is developing a portfolio of clinical-stage products that aims to address significant unmet medical needs in oncology and rare diseases. Telix is listed on the Australian Securities Exchange (ASX: TLX).

Visit www.telixpharma.com for further information about Telix, including details of the latest share price, announcements made to the ASX, investor and analyst presentations, news releases, event details and other publications that may be of interest. You can also follow Telix on LinkedIn.

TLX250-CDx has not received a marketing authorisation in any jurisdiction. Telix's lead imaging product, gallium-68 (⁶⁸Ga) gozetotide injection (also known as ⁶⁸Ga PSMA-11 and marketed under the brand name Illuccix^®), has been approved by the U.S. Food and Drug Administration (FDA),^[6] by the Australian Therapeutic Goods Administration (TGA),^[7] and by Health Canada.^[8]

Telix's SENSEI^® ultra-miniaturised robotic gamma probe is registered as a Class 1 device with the FDA, and has attained a Conformité Européenne (CE) Mark for use in the European Economic Area for intra-operative detection of sentinel lymph nodes.^[9]

Telix Investor Relations

Ms. Kyahn WilliamsonTelix Pharmaceuticals LimitedSVP Investor Relations and Corporate CommunicationsEmail: kyahn.williamson@telixpharma.com

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Except as required by applicable laws or regulations, Telix does not undertake to publicly update or review any forward-looking statements. Past performance cannot be relied on as a guide to future performance. Readers should read this announcement together with our material risks, as disclosed in our most recently filed reports with the ASX and on our website.

©2023 Telix Pharmaceuticals Limited. The Telix Pharmaceuticals and Illuccix name and logo are trademarks of Telix Pharmaceuticals Limited and its affiliates (all rights reserved).

[1] Telix ASX disclosure 7 November 2022.[2] Therapies targeting programmed death-ligand 1, a trans-membrane protein that plays a vital role in inhibiting immune response.[3] World Cancer Research Fund (WCRF): https://www.wcrf.org/dietandcancer/breast-cancer-statistics.[4] Globocan 2020.[5] American Cancer Society: https://www.cancer.org/cancer/types/breast-cancer/about/types-of-breast-cancer/triple-negative.html[6] Telix ASX disclosure 20 December 2021.[7] Telix ASX disclosure 2 November 2021.[8] Telix ASX disclosure 14 October 2022.[9] Lightpoint Medical media release 20 January 2021.