Blue Earth Diagnostics’ Axumin, a radioactive diagnostic agent for injection, was approved May 27 the U.S. Food and Drug Administration (U.S. FDA) for positron emission tomography (PET) imaging in men with suspected prostate cancer (PC) recurrence grounded on elevated prostate specific antigen (PSA) levels after previous treatments.

“Imaging tests are not able to determine the location of the recurrent prostate cancer when the PSA is at very low levels,” said Dr. Libero Marzella, director of the Division of Medical Imaging Products in the U.S. FDA’s Center of Drug Evaluation and Research, in a press release. “Axumin is shown to provide another accurate imaging approach for these patients.”

Axumin’s safety and efficacy for imaging recurrent PC patients were evaluated in two studies:

• First, a comparison of 105 Axumin scans in male subjects with suspected recurrence of prostate cancer to the histopathology obtained by prostate biopsy and by biopsies of suspicious-looking imaged lesions. Radiologists read the scans on site and afterwards three independent radiologists read the same scans, in a blinded study.
• Second, an evaluation of how much 96 Axumin and C11 choline (a prior U.S. FDA-approved PET scan imaging test) scans – in patients with median PSA values of 1,44 ng/mL were in agreement with each other. Radiologists first read the scans on site and then the same three independent radiologists.

Results showed that the independent scan readings were consistant with the onsite scan readings.  The two studies were good cause for the U.S. FDA’s decision to approve Axumin for imaging prostate cancer in men with elevated PSA levels after previous treatments.

Axumin is a radioactive drug, which means it must be handled with appropriate safety measures to minimize radiation exposure to patients and healthcare providers during administration. Axumin PET imaging is susceptible to image interpretation errors and so negative image does not mean recurrent PC isn’t present. Similarly, a positive image should not be considered a confirmation of the presence of recurrent PC. Clinical correlation, potentially including histopathological (the study of tissue changes caused by disease) evaluation of the suspected recurrence site, is therefore recommended.

Patients reportedly experienced adverse reactions such as injection site pain, redness, and a metallic taste in their mouths.

PC is the second leading cause of death from cancer for men in the United States. In patients with suspected cancer recurrence after the first treatment, accurate staging is critical to improve management and outcomes.