TALAPRO-2: Talazoparib + Enzalutamide in HRR-Altered First-Line mCRPC

Authored by Natalia Gandur, published on 2026-07-05 14:46:43.0

The algorithm is broadly aligned with contemporary mCRPC management: maintain ADT, perform HRR (germline/somatic) testing early, and consider PARP inhibitor combinations for HRR-altered disease. Placement of talazoparib + enzalutamide in the first-line mCRPC setting is supported by the TALAPRO-2 trial and subsequent regulatory/guideline adoption, with the strongest benefit signal in BRCA1/2 alterations. Key practical considerations (marrow reserve/CBC monitoring, renal dosing, drug interactions) appropriately reflect PARP inhibitor toxicity management.

1. Confirm mCRPC

Metastatic castration-resistant pThis pathway applies to patients with metastatic castration-resistant prostate cancer (mCRPC) being considered for first-line mCRPC treatment. Confirm: Metastatic prostate cancer Castration-resistant transition Castrate testosterone level Ongoing ADT or prior bilateral orchiectomy No prior systemic therapy for mCRPC, or clarify which prior therapies were given in the hormone-sensitive setting Current symptoms, disease burden, visceral disease, bone disease, pain, performance status, and need for response This is a first-line mCRPC treatment-selection pathway, not a metastatic castration-sensitive prostate cancer pathway.rostate cancer
- 2. Continue ADT / castration backbone
  
  Continue androgen deprivation therapy throughout mCRPC treatment unless the patient has had bilateral orchiectomy. Confirm: GnRH agonist or antagonist is ongoing, or prior bilateral orchiectomy Testosterone remains in the castrate range Bone health, fracture risk, cardiovascular risk, metabolic risk, and ADT-related symptoms are being addressed Supportive care considerations: Bone-protective agent when indicated Calcium/vitamin D according to local practice Pain control and skeletal event prevention Cardiovascular and metabolic risk optimization
  - 3. First-line mCRPC setting
    
    Confirm that the patient is being considered for first-line systemic therapy for mCRPC. Review prior exposure in earlier disease states: Prior ARPI in mCSPC or nmCRPC Prior docetaxel in mCSPC Prior abiraterone, enzalutamide, apalutamide, or darolutamide Prior PARP inhibitor exposure Prior platinum or radiopharmaceutical therapy Current symptoms, disease tempo, visceral disease, and need for rapid response Prior ARPI exposure may affect expected benefit and sequencing decisions. Consider clinical trial, taxane, radioligand therapy eligibility, or alternative standard mCRPC options depending on prior therapy and patient factors.First-line mCRPC treatment selection (including ARPI- and biomarker-driven options) is guideline-defined and depends on prior exposures in mCSPC and earlier disease states.
    - 4. Obtain HRR testing
      
      Confirm germline and/or somatic testing for homologous recombination repair (HRR) alterations. HRR genes relevant to talazoparib + enzalutamide selection include: ATM, ATR, BRCA1, BRCA2, CDK12, CHEK2, FANCA, MLH1, MRE11A, NBN, PALB2, and RAD51C. Testing may include: Tissue-based tumor testing Circulating tumor DNA testing Germline testing when appropriate If cfDNA is negative or indeterminate and clinical suspicion remains high, consider tissue testing when feasible. Document whether the alteration is germline or somatic, monoallelic or biallelic when available, and whether the result is clearly treatment-driving under local regulatory guidance.
      - 5. HRR alteration present?
        
        If an eligible HRR alteration is present, proceed to assess suitability for talazoparib + enzalutamide. If no HRR alteration is present, or testing is negative/indeterminate, use an alternative standard first-line mCRPC pathway and consider: Repeat or tissue-based testing if cfDNA is negative/indeterminate and suspicion remains high Germline testing if not previously performed Clinical trial if appropriate Standard mCRPC treatment selection based on prior therapy, symptoms, disease burden, access, and patient goals Do not use talazoparib + enzalutamide solely because HRR status is unknown.
        
        No / Unknown
        
        Follow standard mCRPC treatment pathway
        
        For patients without a qualifying HRR alteration, or when talazoparib + enzalutamide is not suitable, select therapy using a standard mCRPC pathway. Consider: Prior ARPI exposure Prior docetaxel exposure Symptoms and disease tempo Visceral disease PSMA-targeted radioligand eligibility when relevant Taxane suitability Clinical trial availability Molecular profile, including BRCA/HRR, MSI/MMR, TMB and other actionable markers when appropriate Patient goals, access, and toxicity preferences Terminal hand-off:Open the standard first-line mCRPC treatment-selection pathway when available.
        
        Yes
        
        6. Assess suitability for enzalutamide + talazoparib
        
        Assess clinical suitability before starting talazoparib + enzalutamide. Consider: Baseline hemoglobin and marrow reserve Preexisting anemia, neutropenia, or thrombocytopenia Renal function Prior chemotherapy or radiotherapy Frailty, falls risk, dizziness, fatigue, and cognitive vulnerability Seizure history or predisposing neurologic risk Concomitant medications and drug interactions Blood pressure and cardiovascular risk Bone health and fracture risk Access, regulatory status, cost, and patient goals In patients with preexisting anemia, consider baseline vitamin B12, folate, and iron studies before starting talazoparib. This is an implementation assessment, not a biomarker decision point alone.
        
        7. Eligible / feasible?
        
        Proceed if: mCRPC is confirmedADT/castration backbone is maintainedA qualifying HRR alteration is presentTalazoparib + enzalutamide is supported by regulatory approval/access and clinical judgmentBaseline marrow reserve and renal function are acceptable or manageableEnzalutamide-related risks are acceptableThe patient understands expected benefits, monitoring needs, and toxicity risks If not eligible or not feasible, use an alternative standard mCRPC pathway or clinical trial.
        
        Yes
        
        Talazoparib + enzalutamide + ongoing ADT
        
        For eligible patients with HRR gene-mutated first-line mCRPC, consider talazoparib + enzalutamide with ongoing ADT when supported by regulatory approval, access, and clinical judgment. Dose: Talazoparib 0.5 mg PO once daily Enzalutamide 160 mg PO once daily Continue ADT with GnRH analog or confirm prior bilateral orchiectomy Before starting: Review CBC with differential and platelets Assess renal function and liver tests Review blood pressure and cardiovascular risk Review falls risk, seizure risk, fatigue risk, and drug interactions Assess baseline anemia; consider B12, folate, and iron studies if already anemic Counsel regarding hematologic toxicity, fatigue, dizziness/falls, nausea, appetite loss, and monitoring needs
        
        Monitoring and anemia management
        
        Suggested monitoring: CBC with differential and platelets at baseline and at least monthly, or more frequently early in treatment or if abnormal Renal function and liver tests Blood pressure Symptoms of anemia, fatigue, dizziness, falls, nausea, appetite loss Neutropenia, thrombocytopenia, infection or bleeding risk PSA trend and clinical symptoms Imaging response according to disease status and local practice Adherence and drug interactions Quality of life and functional status For patients with baseline anemia or early hemoglobin decline, monitor CBC more closely during the first 3 to 4 months. Enzalutamide-related monitoring: Falls and dizziness Fatigue Hypertension Cognitive or functional decline in vulnerable patients Drug interactions Rare seizure risk or predisposing neurologic conditions Bone health and fracture risk Anemia and myelosuppression are key implementation issues with talazoparib + enzalutamide. If significant anemia develops:- Assess symptoms, hemoglobin trajectory, transfusion need, bleeding, renal function, inflammation, marrow reserve, and disease status- Evaluate reversible contributors such as vitamin B12, folate, and iron deficiency if not already checked- Provide supportive care and transfusion when clinically indicated For hemoglobin <8 g/dL or grade 3-4 anemia:- Hold talazoparib- Monitor CBC closely until recovery- Resume talazoparib at a reduced dose when appropriate Talazoparib dose-reduction sequence in mCRPC:0.5 mg daily → 0.35 mg daily → 0.25 mg daily → 0.1 mg daily. Discontinue talazoparib if more than 3 dose reductions are required or if MDS/AML is confirmed. Expert implementation caveat:If early hemoglobin decline suggests the patient is likely to develop grade 3 anemia, preemptive talazoparib dose reduction may be considered to prevent severe anemia while maintaining therapy.
        
        9. At progression
        
        At radiographic, clinical, or PSA progression, reassess the full disease context. Confirm: Castration-resistant status and testosterone level Prior ARPI exposure Prior PARP inhibitor exposure Prior chemotherapy exposure PSMA PET / radioligand therapy eligibility when relevant Taxane suitability Molecular profile and possibility of repeat testing Clinical trial eligibility Symptoms, disease tempo, visceral disease, and patient goals Terminal hand-off: Open post-PARP / post-ARPI mCRPC sequencing pathway when available. Avoid looping back within this algorithm; progression should trigger reassessment and next-line pathway selection.
        
        Key caveats: biomarker, safety, access, monitoring
        
        Key takeaways: 1. Talazoparib + enzalutamide is a first-line mCRPC option for selected patients with HRR gene-mutated disease when supported by approval, access, and clinical judgment. 2. HRR testing should be confirmed before treatment selection, including germline and/or somatic testing as appropriate. 3. Document alteration subtype when available, including germline vs somatic, copy-number loss/deletion, monoallelic vs biallelic status, and gene involved. 4. Hematologic toxicity, especially anemia, is the key implementation issue; baseline CBC, marrow reserve, and early hemoglobin trajectory matter. 5. In patients with preexisting anemia, consider vitamin B12, folate, and iron studies before starting talazoparib. 6. Enzalutamide-related risks, including fatigue, falls, hypertension, drug interactions, cognitive/functional vulnerability, and rare seizure risk, should be considered during patient selection and monitoring. 7. At progression, patients need post-PARP / post-ARPI sequencing reassessment rather than automatic continuation of the same pathway. 8. Use should be individualized according to local regulatory approval, access, prior therapy, toxicity risk, patient goals, and expert review.
        
        No
        
        Use alternative standard mCRPC pathway
        
        9. At progression
        
        At radiographic, clinical, or PSA progression, reassess the full disease context. Confirm: Castration-resistant status and testosterone level Prior ARPI exposure Prior PARP inhibitor exposure Prior chemotherapy exposure PSMA PET / radioligand therapy eligibility when relevant Taxane suitability Molecular profile and possibility of repeat testing Clinical trial eligibility Symptoms, disease tempo, visceral disease, and patient goals Terminal hand-off: Open post-PARP / post-ARPI mCRPC sequencing pathway when available. Avoid looping back within this algorithm; progression should trigger reassessment and next-line pathway selection.
        
        Key caveats: biomarker, safety, access, monitoring
        
        Key takeaways: 1. Talazoparib + enzalutamide is a first-line mCRPC option for selected patients with HRR gene-mutated disease when supported by approval, access, and clinical judgment. 2. HRR testing should be confirmed before treatment selection, including germline and/or somatic testing as appropriate. 3. Document alteration subtype when available, including germline vs somatic, copy-number loss/deletion, monoallelic vs biallelic status, and gene involved. 4. Hematologic toxicity, especially anemia, is the key implementation issue; baseline CBC, marrow reserve, and early hemoglobin trajectory matter. 5. In patients with preexisting anemia, consider vitamin B12, folate, and iron studies before starting talazoparib. 6. Enzalutamide-related risks, including fatigue, falls, hypertension, drug interactions, cognitive/functional vulnerability, and rare seizure risk, should be considered during patient selection and monitoring. 7. At progression, patients need post-PARP / post-ARPI sequencing reassessment rather than automatic continuation of the same pathway. 8. Use should be individualized according to local regulatory approval, access, prior therapy, toxicity risk, patient goals, and expert review.

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