Role of Piflufolastat F 18 Reinforced in Prostate Cancer With Low PSA Levels
The secondary analysis of the phase 3 CONDOR study showed that given prior positron emission tomography, piflufolastat F 18 demonstrated changes in intended management, reinforcing the agent's clinical utility.
Piflufolastat F 18 (Pylarify) given before positron emission tomography (PET) scanning demonstrated changes in intended management in 39.1% of patients with a prostate-specific antigen (PSA) level below 0.5 ng/mL, according to findings from the secondary analysis of the phase 3 CONDOR trial (NCT03739684).1
Data from the study were presented at 2023 American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU) in San Francisco. In the analysis, 74.1% (20/27) of patients had a change in management which led to an escalation of treatment from local salvage therapy to systemic therapy, or a shift from observation to initiating treatment. In 18 of the 20 patients who had an intensification of treatment, piflufolastat F 18 identified lesions.
The clinical utility of piflufolastat F18 PET/CT is supported by this analysis in men with low PSA levels that range from 0.2ng/mL-0.5 ng/mL.
“[Piflufolastat F 18] has the potential to contribute meaningful and actionable information that can be used to personalize treatment plans in men with low PSA levels,” said Frederic Pouliot, MD, Hospitalier Universitaire de Québec-Université Laval, in a presentation of these data. “The data we presented at ASCO GU emphasize the clinical utility of piflufolastat F 18 to assess the relevance and applicability of intended treatment management plans.”
Piflufolastat F 18 is a a prostate-specific membrane antigen (PSMA)-targeted radiopharmaceutical and is approved in the United States for imaging patients with prostate cancer at the time of initial staging and at disease recurrence.
Investigators reviewed data from a subset of 69 patients from the CONDOR trial who had a PSA level below 0.5 ng/mL.1 In the study, patients received a single dose injection of piflufolastat F 18 prior to PET imaging and completed pre- and post-imaging questionnaires about the intended management of their prostate cancer.
The goal of the study was to evaluate the clinical utility of piflufolastat F 18 scanning in men with very low/low PSA levels (< 0.5 ng/mL). Researchers assessed the primary end point of correct localization rate and the secondary end points of percentage of participants with a change in intended prostate cancer treatment plans due to piflufolastat F 18 imaging results, the change from pre- to post- piflufolastat F 18 dosing in blood pressure and heart rate, collection of concomitant medications, and collection of medical procedures.
Male patients 18 years of age and older were enrolled in the trial if they had histopathologically confirmed prostate adenocarcinoma with suspected recurrence of prostate cancer based on rising PSA after definitive therapy, negative or equivocal findings for prostate cancer on conventional imaging performed as part of standard of care workup within 60 days prior to the start of the study, and a life expectancy of 6 months or more.
In the trial, 208 men with a median baseline PSA of 0.8 ng/mL (range, 0.2-98.4 ng/mL) were enrolled and given piflufolastat F 18. Findings revealed that the correct localization rate was 84.8%-87.0% (lower bound of 95% CI, 77.8-80.4), and the disease detection rate was 59%-66%.2
The trial achieved its primary end point of demonstrating disease localization in the setting of negative standard imaging. Additionally, piflufolastat F 18 led to clinically meaningful and actionable information, supporting the utility of piflufolastat F 18 to localize disease in male patients with recurrent prostate cancer.
“We had observed in the CONDOR phase 3 study of men with biochemically recurrent prostate cancer, that nearly two-thirds of patients had their treatment plan altered, attributed to learnings from the scan itself,” stated Jean-Claude Provost, MD, chief medical officer of Lantheus, in a press release. “These data in the subset of men with low PSA levels reinforces the impact and potential role of piflufolastat F 18 in informing patient management decisions in real-world scenarios.”
