Health Canada Expands Indication for Illuccix Diagnostic Kit for PSMA-Targeted Radioligand Therapy in mCRPC

Health Canada has approved a label expansion for Illuccix (TLX591-CDx), a kit for the preparation of Gallium-68 gozetotide prostate-specific membrane antigen (PSMA-11)–PET injection, to select patients with metastatic castration-resistant prostate cancer (mCRPC) who are eligible for treatment with lutetium Lu 177 vipivotide tetraxetan (Pluvicto; formerly 177Lu-PSMA-617).¹

Imaging with an approved gallium-based PSMA-PET agent is required for patients to qualify for radioligand therapy.

This regulatory decision expands on the imaging agent’s prior indications for staging and re-staging intermediate and high-risk prostate cancers, as well as localizing tumor tissue in recurrent prostate cancer. The imaging product has been approved in Canada since October 2022.

“We welcome Health Canada’s decision to expand the label for Illuccix. This will further improve access to advanced prostate cancer imaging and provide doctors with critical information to help make treatment decisions with confidence,” Kevin Richardson, chief executive officer of Telix Precision Medicine, stated in a news release. “This reflects Telix’s ongoing commitment to supporting patients with cancer and empowering the doctors who care for them across more stages of the patient journey.”

Illuccix was approved by the FDA in December 2021 as a radioactive diagnostic agent for PET of PSMA-positive lesions in patients with prostate cancer with suspected metastasis who are candidates for initial definitive therapy, and in those with suspected recurrence based on elevated serum prostate-specific antigen level.² In March 2023, the indication was expandedto include the selection of patients with mCRPC for whom lutetium Lu 177 vipivotide tetraxetan is indicated.³

The agent is also approved for use by the Australian Therapeutic Goods Administration.¹

Two prospective, open-label trials, PSMA-PreRP (NCT02919111) and PSMA-BCR (NCT02918357), supported the approval of this imaging product and demonstrated its efficacy as a detection method in prostate cancer.⁴

Notably, Illuccix was used to detect prostate cancer and identify eligible patients for PSMA-based radioligand therapy in the phase 3 VISION trial (NCT03511664). Findings from the study supported the FDA approval of lutetium Lu 177 vipivotide tetraxetan in March 2022 for the treatment of adult patients with PSMA-positive mCRPC with prior exposure to anticancer therapies.⁵

“As targeted radionuclide therapy for prostate cancer becomes more prevalent in Canada, it is critical for doctors to understand who may or may not respond to those treatments,” Dr Francois Lamoureux, president of the Canadian Association of Nuclear Medicine, added in the news release.¹ “In the VISION trial, 68Ga-PSMA-11 PET/CT7 was shown to be a powerful and highly accurate tool for detecting prostate cancer and informing patient management.”

VISION was a randomized, multicenter, open-label trial that evaluated patients with PSMA-positive mCRPC who had progressed on at least 1 androgen receptor pathway inhibitor and 1 or 2 prior taxane regimens. All patients had received a GnRH analog or undergone prior bilateral orchiectomy. Upon enrollment, patients were randomly assigned 2:1 to receive 7.4 GBq of the radioligand every 6 weeks plus best supportive care (BSC; n = 551) vs BSC alone (n = 280) for 6 doses.⁵

The trial met its coprimary end points of improved overall survival (OS) and radiographic progression-free survival (rPFS) with lutetium Lu 177 vipivotide tetraxetan. The median OS for those treated with the radioligand was 15.3 months (95% CI, 14.2-16.9) vs 11.3 months (95% CI, 9.8-13.5) with BSC alone (HR, 0.62; 95% CI, 0.52-0.74; P < .001). Interpretation of the magnitude of the rPFS effect was limited by a high degree of censoring from early drop out in the control arm.

“PSMA-targeted theranostics are widely considered to be the future of prostate cancer treatment. It is therefore tremendous that we can now offer Illuccix in this additional setting, for patients who are candidates for PSMA-targeted therapy, through our national network,” André Gagnon, president of Isologic, concluded.¹

References

1. Health Canada approves label expansion for Telix’s Illuccix to include patient selection for PSMA-targeted therapy.News release. Telix Pharmaceuticals. October 4, 2024. Accessed October 7, 2024. https://telixpharma.com/news-views/health-canada-approves-label-expansion-for-telixs-illuccix-to-include-patient-selection-for-psma-targeted-therapy/
2. FDA Approves Telix’s prostate cancer imaging product, Illuccix. News release. Telix Pharmaceuticals. December 20, 2021. Accessed October 7, 2024. https://telixpharma.com/news-views/fda-approves-telixs-prostate-cancer-imaging-product-illuccix/
3. FDA approves expanded indication for Telix’s Illuccix to include patient selection for PSMA-directed radioligand therapy. News release. Telix Pharmaceuticals. March 16, 2023. Accessed October 7, 2024. https://telixpharma.com/news-views/fda-approves-expanded-indication-for-telixs-illuccix-to-include-patient-selection-for-psma-directed-radioligand-therapy/
4. TLX591-CDx (Illuccix). Prescribing information. Telix. 2023. Accessed October 7, 2024. https://illuccixhcp.com/wp-content/uploads/illuccix-prescribing-information.pdf
5. FDA approves Pluvicto for metastatic castration-resistant prostate cancer. FDA; March 23, 2022. Accessed October 7, 2024. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pluvicto-metastatic-castration-resistant-prostate-cancer#:~:text=On%20March%2023%2C%202022%2C%20the,metastatic%20castration%2Dresistant%20prostate%20cancer%20(