Bexlutry (Lu-177 Dotatate) for SSTR-Positive GEP-NETs: PRRT Dosing and Safety Monitoring

　　1.Disease Selection and PRRT Position

　　Gastroenteropancreatic neuroendocrine tumors(GEP-NETs)arise from neuroendocrine cells in foregut,midgut,or hindgut organs.Many are well differentiated and slow growing,but advanced disease commonly metastasizes to liver;functional tumors may cause flushing,diarrhea,hypoglycemia,or carcinoid syndrome.Peptide receptor radionuclide therapy is appropriate when SSTR imaging shows homogeneous lesion uptake.Negative SSTR,diffuse hepatic/bone replacement limiting target definition,severe renal impairment,or very limited life expectancy usually preclude PRRT.Unresectable,metastatic,progressive,SSTR-positive adults may be considered for Lu-177 dotatate.

　　2.Product and Mechanism

　　Bexlutry contains lutetium Lu-177 dotatate,a radiolabeled octreotate peptide developed by Curium Pharma and approved by the US FDA in September 2026 for adults with SSTR-positive GEP-NETs.It follows an equivalence/505(b)(2)pathway versus the established Lu-177 dotatate reference product,focusing on consistent active ingredient and radiopharmaceutical supply rather than replacing specialist judgment on indication and dosing.

　　The peptide binds SSTR2-dominant somatostatin receptors,internalizes,and delivers beta radiation to tumor cells,causing DNA damage and cytotoxicity.Because SSTRs are also present in normal pancreatic,lymphoid,and renal tubular tissue,amino-acid infusion,fractionated dosing,and hydration are used to reduce off-target renal and systemic exposure.

　　3.Indication and Administration

　　Indicated for adults with SSTR-positive GEP-NETs of foregut,midgut,or hindgut origin,mainly unresectable or metastatic progressive disease without curative surgery.Do not start without positive SSTR imaging or outside facilities licensed for radiopharmaceutical therapy.

　　Reference regimen:

　　Dose:7.4GBq(200mCi)IV once every 8 weeks for 4 cycles;adjust for actual activity,body weight,marrow/renal function,and institutional rules.

　　Renal protection:amino-acid infusion with lysine/arginine before and/or during therapy to reduce tubular reabsorption;timing and volume per center protocol.

　　SSA coordination:hold long-acting octreotide/lanreotide about 4 weeks before each cycle when appropriate;short-acting octreotide for carcinoid symptoms may continue but stop at least 24 hours before PRRT.Consider SSA timing relative to SSTR-PET scheduling.

　　Facility:nuclear medicine with radiation-safety licensure and oncology/neuroendocrine input.

　　4.Key Efficacy Evidence

　　Lu-177 dotatate evidence is anchored by NETTER-1 in progressive,well-differentiated,SSTR-positive midgut NET:7.4GBq every 8 weeks for 4 cycles versus high-dose long-acting octreotide showed approximately 65.2%vs 10.8%estimated 20-month progression-free survival,18%vs 3%objective response,and hazard ratio about 0.21 for progression or death;ERASMUS and broader GEP-NET experience support safety and dosing generalization.Bexlutry was approved on pharmaceutical comparability,quality,and bioequivalence-related data without repeating a large phase III.

　　5.Monitoring and Management

　　Marrow:CBC with differential before each cycle;watch anemia,neutropenia,thrombocytopenia,and lymphopenia.Persistent severe cytopenias or suspected MDS/acute leukemia require hematology review and treatment hold;secondary MDS/leukemia are recognized delayed risks.

　　Kidney:baseline and serial creatinine/eGFR and urinalysis/proteinuria;amino-acid protection,hydration,and frequent voiding reduce bladder and renal exposure.Significant renal impairment or rising proteinuria prompts reevaluation.

　　Liver:ALT,AST,bilirubin,albumin per cycle;hold or discontinue by hepatotoxicity grade.

　　Carcinoid/hormonal crisis:flushing,diarrhea,bronchospasm,hypotension/hypertension,or arrhythmia around infusion;have somatostatin analogs,corticosteroids,fluids,and symptomatic therapy ready,with endocrine/nuclear joint management for high-risk functional tumors.

　　Radiation safety:manage excreta,contacts,pregnancy,and lactation per regulations;pregnancy test before therapy in people with reproductive potential,effective contraception about 7 months after last dose for women and 4 months for men,avoid breastfeeding to the labeled interval.

　　Other:nausea/vomiting often related to amino-acid infusion;assess anaphylaxis,alopecia,fatigue,and interactions with other SSAs,nephrotoxins,or myelosuppressive drugs.