PROSTASCINT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PROSTASCINT (PROSTASCINT).
PROSTASCINT is a murine monoclonal antibody fragment (capromab pendetide) conjugated to the chelating agent glycyl-tyrosyl-lysyl-diethylenetriaminepentaacetic acid (GYK-DTPA) and labeled with indium-111. It binds to the intracellular epitope of prostate-specific membrane antigen (PSMA) expressed on prostate epithelial cells and is used for imaging prostate cancer.
| Metabolism | Capromab pendetide is a monoclonal antibody fragment; metabolism is via catabolism to amino acids and small peptides. The indium-111 label is not metabolized and decays physically. |
| Excretion | Renal: ~90% (predominantly as intact tracer), Fecal: <5% |
| Half-life | Terminal elimination half-life: 2.6 ± 0.7 days (requires 2 weeks for complete clearance; used for radioimmunodetection within 5–7 days post-injection) |
| Protein binding | ~90% (binding to plasma proteins, likely immunoglobulins and albumin) |
| Volume of Distribution | 5.5 L (not weight-adjusted; approximates intravascular space with slow distribution to extravascular tumor sites) |
| Bioavailability | IV: 100% (not administered via other routes) |
| Onset of Action | IV: Localization in tumor sites detectable by gamma camera within 24–48 hours (maximal target-to-background ratios at 5–7 days) |
| Duration of Action | IV: Tracer remains detectable in tumor tissue up to 14 days; optimal imaging window 5–7 days post-administration |
5 mCi (185 MBq) intravenously over 5 minutes, single dose.
| Dosage form | VIAL |
| Renal impairment | No specific dose adjustment recommended; caution in severe renal impairment (GFR <30 mL/min) due to potential radiation clearance delay. |
| Liver impairment | No specific adjustment for Child-Pugh class; caution in severe hepatic impairment due to altered clearance. |
| Pediatric use | Safety and efficacy not established; not recommended for pediatric patients. |
| Geriatric use | No specific dose adjustment; follow standard adult dosing with consideration of renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PROSTASCINT (PROSTASCINT).
| Breastfeeding | Indium-111 is a radioactive isotope with a physical half-life of 2.8 days. Radioactive iodine may concentrate in breast milk. It is recommended to discontinue breastfeeding after administration. No M/P ratio available. To reduce radiation exposure to the infant, breastfeeding should be interrupted for a period based on the decay of indium-111 (typically at least 10 half-lives, i.e., 28 days). Pump and discard milk during this time. |
| Teratogenic Risk | PROSTASCINT (indium-111 capromab pendetide) is a murine monoclonal antibody labeled with indium-111 used for imaging. No adequate human data on fetal risk. Animal studies are not available. The radiopharmaceutical component emits radiation; fetal radiation exposure may increase the risk of congenital anomalies and childhood malignancies. Use in pregnant women is contraindicated unless potential benefit outweighs risks. First trimester exposure poses highest risk of teratogenesis; second and third trimester exposure may increase risk of childhood cancer. |
■ FDA Black Box Warning
Not applicable.
| Serious Effects |
["Hypersensitivity to capromab pendetide, indium-111, or any component of the formulation","Pregnancy: potential fetal harm from radiation"]
| Precautions | ["Risk of hypersensitivity reactions, including anaphylaxis","Use of murine antibodies may cause human anti-mouse antibody (HAMA) response, potentially affecting subsequent murine antibody-based diagnostics or therapeutics","Radiation exposure from indium-111; risk of secondary malignancies","Limited data in patients with renal impairment"] |
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| Fetal Monitoring | Maternal: Monitor for allergic or hypersensitivity reactions (e.g., rash, urticaria, anaphylaxis) during and after infusion. Fetal: If inadvertently administered during pregnancy, assess fetal radiation dose estimate and consult radiation safety officer. Fetal monitoring for growth and development if exposure occurred. |
| Fertility Effects | Indium-111 capromab pendetide is a radiopharmaceutical. Animal reproductive studies have not been conducted. Radiation exposure can damage gonadal tissues, potentially impairing fertility in both males and females. The effect is dose-dependent; diagnostic doses are low but may carry a small risk of transient or permanent infertility. No specific human data on fertility effects. |