Early data suggest 18F-DCFPyL PET/CT scans can change patient management

A media release issued yesterday by Progenics Pharmaceuticals states that the investigational imaging agent 18F-DCFPyL changed physician behavior in the management of biochemically recurrent prostate cancer in > 65 percent of patients. However, we note that this behavior change (to date) has only been documented in the first 55 of a projected 200 patients (see below).

18F-DCFPyL (also referred to more simply as “PyL”) is an investigational, radioactive, fluorinated, PSMA-targeted imaging agent that is being studied for use in conjugation with PET scanning to identify potential bone and soft tissue metastases in men with progressive forms of prostate cancer.

The media release issued yesterday by Progenics is based on early data from an ongoing clinical trial of 18F-DCFPyL (the so-called CONDOR trial). The early data from this trial were reported by Rousseau et al. in the Journal of Nuclear Medicine.

The following core data are reported by Rousseau et al.:

  • The trial had enrolled 130 patients who met specific criteria indicative of biochemical recurrence after first-line treatment by radical prostatectomy or radiotherapy with curative intent and who were given a PET/CT scan with 18F-DCFPyL as the imaging agent.
  • 84.6 percent of patients had positive results on this scan, with varying levels of confidence:
    • 81.5 percent of positive scans were of high confidence
    • 13.1 percent of positive scans were of moderate confidence
    • 5.4 percent of positive scans were of low confidence
  • 18F-DCFPyL PET/CT scans were able to identify the location of recurrent prostate cancer in
    • 60 percent of men with a PSA level of 0.4 to < 0.5 ng/ml
    • 78 percent of men with a PSA level of 0.5 to < 1.0 ng/ml
    • 72 percent of men with a PSA level of 1.0 to < 2.0 ng/ml
    • 92 percent of men with a PSA level of ≥ 2.0 ng/ml
  • Most patients had less than four identifiable lesions:
    • One lesion in 40.8 percent of subjects
    • Two lesions in 8.5 percent of subjects
    • Three lesions in 4.6 percent of subjects
  • Active disease was most often identified in
    • Regional lymph nodes (43.9 percent)
    • The prostate bed and/or seminal vesicles (26.9 percent)
    • Distant lymph nodes (24.6 percent)
    • Bone (20.0 percent)
    • Lung (2.3 percent)
    • Other sites, not including the liver (0.8 percent)
  • Post-scan changes in management were evaluable in 55 of the 130 patients
    • Changes in treatment intent were documented in 36/55 subjects (65.5 percent).
    • Disease stage also changed in 18/55 subjects (65.5 percent).
    • Management plans were changed in 48/55 subjects (87.3 percent).
  • Mild adverse events after the scan were documented in 22/130 subjects (16.9 percent); all such AEs resolved completely.

Rousseau et al. conclude that

18F-DCFPyL PET/CT is safe and sensitive for the localization of biochemical recurrence of prostate cancer. This test improved decision making for referring oncologists and changed management for the majority of subjects.

The Phase III CONDOR trial is expected to enroll a total of 200 patients by some time later this year, and full results of the trial are projected to be available early in 2020.

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