PSMA therapy is a targeted approach for certain cancers, particularly prostate cancer. It delivers therapeutic agents precisely to cancer cells, minimizing impact on healthy tissues. This offers new possibilities for patients whose disease has progressed despite other treatments. PSMA therapy targets and eliminates cancer cells.
Understanding Prostate-Specific Membrane Antigen (PSMA)
Prostate-Specific Membrane Antigen, or PSMA, is a protein found on the surface of cells. It is particularly abundant on prostate cancer cells, including those that have spread to other parts of the body, distinguishing them from most healthy cells where PSMA expression is low. This high expression makes PSMA an attractive target for both diagnostic imaging and therapeutic interventions.
The presence of PSMA on prostate cancer cells allows it to function as a biomarker. This means it can be used to identify prostate cancer cells throughout the body through specialized imaging techniques, such as PSMA PET scans. The ability to visualize these cells helps in accurately staging the disease and determining if a patient is suitable for PSMA-targeted therapies.
Mechanism of PSMA-Targeted Radioligand Therapy
PSMA-targeted radioligand therapy uses a radioligand with two components: a chemical part that binds to PSMA on cancer cells, and a radioactive isotope like Lutetium-177 (Lu-177). When administered, this radioligand travels through the bloodstream and attaches to PSMA-expressing prostate cancer cells. Upon binding, the isotope delivers localized radiation directly to the cancer cells, damaging their DNA and leading to destruction. This ensures the radiation primarily affects cancer cells, with minimal spread to surrounding healthy tissues, due to Lutetium-177’s short-range beta emissions. This focused delivery maximizes cancer cell kill while limiting side effects on non-cancerous organs.
Patient Eligibility for PSMA Therapy
Patient eligibility for PSMA therapy is determined by medical criteria. The therapy is indicated for individuals with metastatic castration-resistant prostate cancer (mCRPC), where cancer has spread and no longer responds to hormone therapy. A key requirement is confirmed PSMA expression in the patient’s tumors, verified through a diagnostic PSMA PET scan.
Other factors include prior treatments; patients are candidates if their disease has progressed after initial hormone therapies or other standard treatments. Overall health status and adequate organ function, particularly of the kidneys and bone marrow, are also assessed to ensure safe treatment tolerance. These evaluations help medical teams determine if PSMA therapy is suitable and safe.
Navigating the PSMA Therapy Journey
The PSMA therapy journey begins with pre-treatment preparations. Patients undergo detailed consultations, scans, and blood tests to confirm readiness and establish baseline health. Hydration is recommended before therapy sessions to support kidney function.
PSMA therapy involves an intravenous infusion of the radioligand in a specialized medical setting. Treatment is delivered in cycles, separated by several weeks, allowing recovery and minimizing cumulative side effects. Multiple cycles are involved, with the exact number determined by patient response and tolerance.
After each treatment, patients are monitored for side effects. Common side effects include dry mouth, fatigue, and changes in blood counts. Kidney function is also closely monitored. These side effects are manageable with supportive care. Ongoing monitoring through follow-up scans and blood tests assesses effectiveness and ensures patient safety.