Assessment of Acute Toxicity of the 99mTc(CO)3-(HE)3-DARPinG3 in Breast Cancer Patients

Purpose: Study the acute toxicity of the radiopharmaceutical [99mTc]Tc-(HE)3-G3 in breast cancer patients. Material and Methods: The study included 10 breast cancer patients (T1-4N0-2M0) with different HER2/neu expression before systemic/surgical treatment, who were injected with 1000 μg of DARPinG3 protein labeled with technetium-99m ([99mTc]Tc-(HE)3-G3). Throughout the study (48 hours), patients were monitored by medical personnel, during which complaints were assessed, heart rate, blood pressure and body temperature were measured before injection of the radiopharmaceutical, as well as 2, 4, 6, 24 and 48 hours after injection. Additionally, laboratory tests such as general and biochemical blood tests and general urine analysis were performed before injection, 48 hours and 7 days later. Results: The presence of complaints, as well as the detection of adverse reactions in breast cancer patients included in the study at the time of injection of the radiopharmaceutical [99mTc]Tc-(HE)3-G3, as well as 2, 4, 6, 24, 48 hours and 7 days after injection were not detected. The measurement of heart rate, body temperature, and blood pressure also showed no pathological abnormalities. According to general and biochemical blood analysis, general urine analysis and ECG results, no abnormalities were found 2, 4, 6, 24 and 48 hours, as well as 7 days after of the radiopharmaceutical [99mTc]Tc-(HE)3-G3. Conclusion: The performed studies fully demonstrate the safety of the clinical use of the radiopharmaceutical [99mTc]Tc-(HE)3-G3 for radionuclide diagnosis of breast cancer patients. The data obtained were confirmed both by the subjective sensations of the patients directly included in the analysis, and by the data of clinical quantitative parameters before the start, as well as 2, 4, 6, 24 and 48 hours after injection of the radiopharmaceutical [99mTc]Tc-(HE)3-G3.