Pharmacology & Mechanism
- Autologous cellular immunotherapy (cancer vaccine).
- Patient’s peripheral blood mononuclear cells (PBMCs) are collected via leukapheresis → incubated ex vivo with a fusion protein (PAP–GM-CSF, prostatic acid phosphatase linked to granulocyte-macrophage colony-stimulating factor).
- Cells are then reinfused into the patient → activates antigen-presenting cells (APCs) → stimulates a T-cell–mediated immune response against prostate cancer cells expressing PAP.
Indication
- Metastatic castration-resistant prostate cancer (mCRPC)
- Asymptomatic or minimally symptomatic
- No visceral metastases
- ECOG performance status 0–1
Administration
- 3 doses given at ~2-week intervals (each prepared individually from patient’s leukapheresis product).
- IV infusion over ~60 minutes.
- Premedication with acetaminophen + antihistamine to reduce infusion reactions.
Toxicities & Monitoring
- Common: infusion reactions (chills, fever, headache, myalgia, fatigue).
- Less common: hypertension, nausea, stroke (rare but reported).
- Monitor during and after infusion for acute reactions.
- No significant myelosuppression (unlike chemotherapy).
Clinical Pearls for Pharmacists
- Not cytotoxic → benefits are modest (median survival gain ~4 months), not associated with PSA decline or radiographic shrinkage.
- Best suited for early mCRPC with low disease burden.
- Requires coordination with leukapheresis centers → logistical complexity.
- Not interchangeable with other immunotherapies (unique autologous product per patient).