Data from Diagnostic Performance of <sup>18</sup>F-DCFPyL-PET/CT in Men with Biochemically Recurrent Prostate Cancer: Results from the CONDOR Phase III, Multicenter Study

Abstract

<div>AbstractPurpose:<p>Current FDA-approved imaging modalities are inadequate for localizing prostate cancer biochemical recurrence (BCR). <sup>18</sup>F-DCFPyL is a highly selective, small-molecule prostate-specific membrane antigen–targeted PET radiotracer. CONDOR was a prospective study designed to determine the performance of <sup>18</sup>F-DCFPyL-PET/CT in patients with BCR and uninformative standard imaging.</p>Experimental Design:<p>Men with rising PSA ≥0.2 ng/mL after prostatectomy or ≥2 ng/mL above nadir after radiotherapy were eligible. The primary endpoint was correct localization rate (CLR), defined as positive predictive value with an additional requirement of anatomic lesion colocalization between <sup>18</sup>F-DCFPyL-PET/CT and a composite standard of truth (SOT). The SOT consisted of, in descending priority (i) histopathology, (ii) subsequent correlative imaging findings, or (iii) post-radiation PSA response. The trial was considered a success if the lower bound of the 95% confidence interval (CI) for CLR exceeded 20% for two of three <sup>18</sup>F-DCFPyL-PET/CT readers. Secondary endpoints included change in intended management and safety.</p>Results:<p>A total of 208 men with a median baseline PSA of 0.8 ng/mL (range: 0.2–98.4 ng/mL) underwent <sup>18</sup>F-DCFPyL-PET/CT. The CLR was 84.8%–87.0% (lower bound of 95% CI: 77.8–80.4). A total of 63.9% of evaluable patients had a change in intended management after <sup>18</sup>F-DCFPyL-PET/CT. The disease detection rate was 59% to 66% (at least one lesion detected per patient by <sup>18</sup>F-DCFPyL-PET/CT by central readers).</p>Conclusions:<p>Performance of <sup>18</sup>F-DCFPyL-PET/CT achieved the study’s primary endpoint, demonstrating disease localization in the setting of negative standard imaging and providing clinically meaningful and actionable information. These data further support the utility of <sup>18</sup>F-DCFPyL-PET/CT to localize disease in men with recurrent prostate cancer.</p><p><i>See related commentary by True and Chen, p. 3512</i></p></div>