FDA Expands Indication of Illuccix Companion Diagnostic for PSMA-Directed Radioligand Therapy in Metastatic Prostate Cancer

The FDA has approved a supplementary new drug application for Illuccix (TLX591-CDx), a kit for the preparation of Gallium-68 gozetotide (prostate-specific membrane antigen [PSMA]–11) injection, for use in the selection of patients with metastatic prostate cancer for whom lutetium Lu 177 vipivotide tetraxetan (Pluvicto; formerly ¹⁷⁷Lu-PSMA-617) is indicated.¹

To qualify for radioligand therapy, patients must be imaged with an approved gallium-based PSMA-PET agent.

Illuccix was utilized in the phase 3 VISION trial (NCT03511664) to detect prostate cancer and identify appropriate patients for PSMA-based radioligand therapy. Data from VISION supported the March 2022 FDA approval of lutetium Lu 177 vipivotide tetraxetan for the treatment of adult patients with PSMA-positive metastatic castration-resistant prostate cancer (mCRPC) who have previously received other anticancer therapies, such as androgen receptor (AR) pathway inhibition and taxane-based chemotherapy.²

“As radioligand therapy for prostate cancer becomes more prevalent, it is critical for doctors to understand who may or may not respond to those treatments,” Oliver Sartor, MD, medical director of the Tulane Cancer Center, stated in a news release.¹ “There’s no doubt that appropriate selection of patients for PSMA targeted radioligand therapy is dependent on appropriate imaging. Ga-68 PSMA-11 PET was used in the VISION trial and, when used in combination with contrast-enhanced CT, represents a powerful tool for detecting prostate cancer and helping guide patient management.”

In December 2021, the FDA approved Illuccix 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 (PSA) level.³

VISION enrolled patients with mCRPC who had at least 1 metastatic lesion at baseline imaging. Patients were required to have progressed on prior treatment with 1 or more approve AR pathway inhibitor and 1 or 2 taxane regimens. At least 1 PSMA-positive metastatic lesion was also required.²

Patients were randomly assigned to lutetium Lu 177 vipivotide tetraxetan at 7.4 GBq (200 mCI) every 6 weeks plus best supportive care (N = 551) or best supportive care alone (n = 280) for a total of 6 doses.

Findings showed that the trial met its co-primary end points, demonstrating a statistically significant improvement in overall survival (OS) and radiographic progression-free survival (rPFS). The median OS was 15.3 months (95% CI, 14.2-16.9) for those treated with lutetium Lu 177 vipivotide tetraxetan compared with 11.3 months (95% CI, 9.8-13.5) for best supportive care alone (HR, 0.62; 95% CI, 0.52-0.74; P < .001). Notably, the magnitude of the rPFS effect was limited due to a high degree of censoring from early drop out in the control arm.

“We welcome the FDA’s decision to expand the label indication for Illuccix,” Kevin Richardson, chief executive officer for Telix Americas, stated in a news release.¹ “This additional indication further demonstrates our continued commitment to support patients fighting prostate cancer and to empower the doctors who treat them. Clinicians now have the ability to use Illuccix in more stages of the patient journey, to confidently and accurately detect and help manage this disease.”

The FDA previously approved Locametz, a radioactive diagnostic agent for PET of PSMA-positive lesions, including selection of patients with metastatic disease for whom lutetium Lu 177 vipivotide tetraxetan is indicated.⁴

References

1. 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 March 16, 2023. https://telixpharma.com/news-views/
2. FDA approves Pluvicto for metastatic castration-resistant prostate cancer. News release. FDA; March 23, 2022. Accessed March 16, 2023. https://www.fda.gov/drugs/resources-information-approved-drugs/
3. FDA Approves Telix’s Prostate Cancer Imaging Product, Illuccix. News release. Telix Pharmaceuticals. December 20, 2021. Accessed March 16, 2023. https://telixpharma.com/news-views/
4. Novartis Pluvicto approved by FDA as first targeted radioligand therapy for treatment of progressive, PSMA positive metastatic castration-resistant prostate cancer. News release. Novartis Pharma AG; March 23, 2022. Accessed March 16, 2023. https://www.globenewswire.com/news-release/2022/