FDA Expands Indication of Illuccix for PSMA-Directed Radioligand Therapy

The FDA has approved a supplementary new drug application (sNDA) for Illuccix, after radiolabeling with gallium (Ga)-68 gozetotide injection, for use in select patients with metastatic prostate cancer who are candidates for lutetium Lu ¹⁷⁷ vipivotide tetraxetan (Pluvicto)-prostate-specific membrane antigen (PSMA)-directed therapy.¹

Data from the phase 3 VISION study (NCT03511664), which helped doctors detect prostate cancer and identify the appropriate patients for PSMA-based radioligand therapy, support this sNDA.

As the only diagnostic agent for suspected metastatic and recurrent prostate cancer that combines the accuracy of gallium imaging with the reliability and flexibility of Telix's distribution network, the expanded indication for Illuccix has the potential to improve access to imaging for patients who are candidates for radioligand therapy.

"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. 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," said “Oliver Sartor, MD, medical director at Tulane Cancer Center, in the press release.

This label expansion for Illuccix, after radiolabeling with Ga-68, is indicated for positron emission tomography (PET) of PSMA positive lesions in men with prostate cancer. These patients include those with suspected metastasis and who are candidates for initial definitive therapy, patients with suspected recurrence based on elevated serum PSA level, and for patients with metastatic prostate cancer, for whom lutetium Lu ¹⁷⁷ vipivotide tetraxetan PSMA-directed therapy is indicated.

The safety of gallium Ga 68 gozetotide was first assessed in the PSMA-PreRP and PSMA-BCR studies. These trials included 960 patients who received 1 dose of Ga-68 gozetotide. Findings showed that the average injected activity was 188.7 ± 40.7 MBq (5.1 ± 1.1 mCi), and the most common adverse events included nausea, diarrhea, and dizziness, occurring at a rate of <1%.

Then, in the phase 3 VISION study, 831 patients were enrolled to assess the primary end points of radiographic progression-free survival (rPFS) and overall survival (OS) in patients with progressive PSMA-positive metastatic castration-resistant prostate cancer (mCRPC) who received lutetium Lu ¹⁷⁷ vipivotide tetraxetan in addition to best standard of care (SOC) vs patients treated with the best SOC alone.²

At a median follow-up of 20.9 months, the median OS observed for patients treated with Lu ¹⁷⁷ vipivotide tetraxetan plus SOC was 15.3 months vs 11.3 months with SOC alone (HR, 0.61; 95% CI, 0.52-0.74; P <.0001). The median observed rPFS with Lu ¹⁷⁷ vipivotide tetraxetan plus SOC was 8.7 months compared with 3.4 months with SOC alone (HR, 0.40; 99.2% CI, 0.29-0.57; P <.001).³

Looking at safety, patients were exposed to Lu ¹⁷⁷ vipivotide tetraxetan for a median of 6.9 months (range, 0.3-10.2) and any-grade AEs were observed in 98.1% of patients who were given the combination vs 82.9% in the SOC arm. The most frequent AEs in the experimental arm were fatigue (43.1%), dry mouth (38.8%), and nausea (35.3%). Fatigue and nausea were also common in the SOC arm at 22.9% and 16.6%, respectively.

"We welcome the FDA's decision to expand the label indication for Illuccix. 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,” said Kevin Richardson, chief executive officer for Telix Americas, the press release.

REFERENCES:

1. FDA approves expanded indication for Telix's Illuccix® to include patient selection for PSMA-Directed radioligand therapy. News release. Telix Pharmaceuticals Limited. March 16, 2023. Accessed March 16, 2023. https://prn.to/3mW1VtA

2. Study of 177Lu-PSMA-617 in metastatic castrate-resistant prostate cancer (VISION). ClinicalTrials.gov. Updated August 11, 2022. Accessed March 16, 2023. https://clinicaltrials.gov/ct2/show/NCT03511664

3. Sartor O, de Bono J, Chi Km, et al. Lutetium-177–PSMA-617 for metastatic castration-resistant prostate cancer. N Engl J Med. 2021; 385(12):1091-1103. doi: 10.1056/NEJMoa2107322