FDA Approves Copper Cu 64 Dotatate Injection for Somatostatin Receptor–Positive NETs

The FDA has approved copper Cu 64 dotatate injection (Detectnet) for the localization of somatostatin receptor–positive neuroendocrine tumors (NETs), according to an announcement from RadioMedix Inc. and Curium Pharma.¹

The positron emission tomography (PET) diagnostic agent is anticipated to launch immediately, according to Curium. Doses will be accessible through several nuclear pharmacies or through the nuclear medicine company.

“Detectnet brings an exciting advancement in the diagnosis of NETs for healthcare providers, patients, and their caregivers,” Ebrahim Delpassand MD, CEO of RadioMedix, stated in a press release. “The phase 3 results demonstrate the clinical sensitivity and specificity of Detectnet which will provide a great aid to clinicians in developing an accurate treatment approach for their [patients with] NETs.”

Copper Cu 64 dotatate adheres to somatostatin receptors with highest affinity for subtype 2 receptors (SSTR2). Specifically, the agent binds to somatostatin receptor–expressing cells, including malignant neuroendocrine cells; these cells overexpress SSTR2. The agent is a positron-producing radionuclide that possesses an emission yield that permits PET imaging.

“Perhaps most exciting is that the 12.7-hour half-life allows Detectnet to be produced centrally and shipped to sites throughout the United States,” added Delpassand. “This will help alleviate shortages or delays that have been experienced with other somatostatin analogue PET agents.”

Two single-center, open-label studies confirmed the efficacy of the diagnostic agent, according to Curium.² In Study 1, investigators conducted a prospective analysis of 63 patients, which included 42 patients with known or suspected NETs according to histology, conventional imaging, or clinical evaluations, and 21 healthy volunteers. The majority of the participants, or 88% (n = 37) had a history of NETs at the time that they underwent imaging. Just under half of patients (44%; n = 28) were men and the majority were white (86%). Moreover, patients had a mean age of 54 years.

Images produced by the PET agent were interpreted to be either positive or negative for NET via 3 independent readers who had been blinded to the clinical data and other imaging information. Moreover, the results from the diagnostic agent were compared with a composite reference standard that was comprised of 1 oncologist’s blinded evaluation of patient diagnosis based on available histopathology results, reports of conventional imaging that had been done within 8 weeks before the PET imaging, as well as clinical and laboratory findings, which involved chromogranin A and serotonin levels.

Additionally, the percentage of patients who tested positive for disease via composite reference as well as through PET imaging was used to quantify positive percent agreement. Conversely, the percentage of participants who did not have disease per composite reference and who were determined to be negative for disease per PET imaging was used to quantify negative percent agreement.

Results showed that the percent reader agreement for positive detection in 62 scans was 91% (95% CI, 75-98) and negative detection was 97% (95% CI, 80-99). For reader 2, these percentages were 91% (95% CI, 75-98) and 80% (95% CI, 61-92), respectively, for 63 scans. Lastly, the percent reader agreement for reader 3 in 63 scans was 91% (95% CI, 75-98) positive and 90% (95% CI, 72-97) negative.

Study 2 was a retrospective analysis in which investigators examined published findings collected from 112 patients; 63 patients were male, while 43 were female. The mean age of patients included in the analysis was 62 years. All patients had a known history of NETs. Results demonstrated similar performance with the PET imaging agent.

In both safety and efficacy trials, a total of 71 patients were given a single dose of the diagnostic agent; the majority of these patients had known or suspected NETs and 21 were healthy volunteers. Adverse reactions such as nausea, vomiting, and flushing were reported at a rate of less than 2%. In all clinical experience that has been published, a total of 126 patients with a known history of NETs were given a single dose of the PET diagnostic agent. A total of 4 patients experienced nausea immediately after administration.

“Curium is excited to bring the first commercially available Cu 64 diagnostic agent to the US market,” Dan Brague, CEO of Curium, North America, added in the release. “Our unique production capabilities and distribution network allow us to deliver to any nuclear pharmacy, hospital, or imaging center its full dosing requirements first thing in the morning, to provide scheduling flexibility to the institution and its patients. We look forward to joining with healthcare providers and our nuclear pharmacy partners to bring this highly efficacious agent to the market.”

References

1. RadioMedix and Curium announce FDA approval of Detectnet (copper Cu 64 dotatate injection) in the US. News release. RadioMedix Inc and Curium. September 8, 2020. Accessed September 9, 2020. https://bit.ly/3m6iC0q.
2. Detectnet. Prescribing information. Curium Pharma; 2020. Accessed September 9, 2020. https://bit.ly/32eZxS3.