Mevrometostat

Last updated

Mevrometostat
Mevrometostat.svg
Clinical data
Other namesPF-06821497
Identifiers
  • 5,8-dichloro-2-[(4-methoxy-6-methyl-2-oxo-1H-pyridin-3-yl)methyl]-7-[(R)-methoxy(oxetan-3-yl)methyl]-3,4-dihydroisoquinolin-1-one
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEMBL
PDB ligand
Chemical and physical data
Formula C22H24Cl2N2O5
Molar mass 467.34 g·mol−1
3D model (JSmol)
  • CC1=CC(=C(C(=O)N1)CN2CCC3=C(C=C(C(=C3C2=O)Cl)[C@@H](C4COC4)OC)Cl)OC
  • InChI=1S/C22H24Cl2N2O5/c1-11-6-17(29-2)15(21(27)25-11)8-26-5-4-13-16(23)7-14(19(24)18(13)22(26)28)20(30-3)12-9-31-10-12/h6-7,12,20H,4-5,8-10H2,1-3H3,(H,25,27)/t20-/m1/s1
  • Key:RXCVUHMIWHRLDF-HXUWFJFHSA-N

Mevrometostat (development code PF-06821497) is an investigational anticancer drug that functions as a potent and selective inhibitor of enhancer of zeste homolog 2 (EZH2). [1] [2] Currently under development by Pfizer, mevrometostat is being investigated primarily for the treatment of metastatic castration-resistant prostate cancer (mCRPC) in combination with enzalutamide.

Contents

Mechanism of action

Mevrometostat is a small molecule inhibitor that targets EZH2, the catalytic subunit of polycomb repressive complex 2 (PRC2). [1] [3] EZH2 plays a crucial role in epigenetic regulation by modifying gene expression patterns that control cellular fate decisions, including differentiation and self-renewal. [1]

In prostate cancer, EZH2 dysregulation contributes to treatment resistance through multiple pathways, including:

Mevrometostat demonstrates dose-dependent EZH2 inhibition, leading to reactivation of tumor suppressor genes while suppressing genes involved in tumor progression. [5]

Clinical development

Phase I/II trials

The primary clinical evaluation of mevrometostat is being conducted through a phase 1/2 dose-expansion study (NCT03460977) investigating the combination of mevrometostat with enzalutamide and androgen deprivation therapy in patients with mCRPC. [6]

The dose-expansion portion of this study enrolled patients with mCRPC who had previously received abiraterone, with evidence of disease progression per modified Prostate Cancer Working Group 3 criteria. [2]

Key efficacy results

In the randomized dose-expansion study, the combination of mevrometostat (1,250 mg twice daily on an empty stomach) plus enzalutamide demonstrated:

  • 49% relative reduction in the rate of progression or death
  • Approximately 8-month improvement in median radiographic progression-free survival (rPFS)
  • Hazard ratio of 0.51 (90% CI: 0.28–0.95) [7]

The median radiographic progression-free survival was 14.3 months with the combination therapy compared to 6.2 months with enzalutamide alone. [8]

Phase III trials

Based on promising phase I/II results, Pfizer has initiated multiple phase 3 clinical trials:

MEVPRO-1 study

The MEVPRO-1 study (NCT06551324) is a randomized phase 3 trial evaluating mevrometostat in combination with enzalutamide versus physician's choice of therapy in patients with mCRPC previously treated with abiraterone acetate. [9] [10]

  • Study design: Randomized 1:1 to receive mevrometostat (875 mg twice daily with food) plus enzalutamide (160 mg daily) versus physician's choice of enzalutamide or docetaxel
  • Target enrollment: Approximately 600 patients
  • Primary endpoint: Blinded independent central review-assessed rPFS per RECIST 1.1 and PCWG3 criteria
  • Key secondary endpoint: Overall survival

MEVPRO-2 study

The MEVPRO-2 study (NCT06629779) is evaluating mevrometostat plus enzalutamide in androgen receptor pathway inhibitor (ARPI)-naïve patients with mCRPC. [11] [12]

Additional development

Pfizer has also initiated phase 3 trials evaluating mevrometostat plus enzalutamide in first-line metastatic castration-sensitive prostate cancer. [8] [13]

Safety profile

The most common adverse events considered related to mevrometostat treatment include:

Dose optimization studies found that mevrometostat 875 mg twice daily with food showed similar efficacy and better safety compared to the 1,250 mg dose on an empty stomach. [15]

Pharmacokinetics

Based on safety and pharmacokinetic findings from phase 1 trials, mevrometostat 875 mg twice daily with food was selected as the recommended dose for phase 3 clinical development in combination with enzalutamide. [16]

Regulatory status

As of 2025, mevrometostat remains an investigational agent under clinical development by Pfizer. The drug has not received regulatory approval from the Food and Drug Administration (FDA), European Medicines Agency (EMA), or other regulatory authorities.

See also

References

  1. 1 2 3 "Mevrometostat (PF-06821497)". Pfizer Oncology Development. Retrieved 11 September 2025.
  2. 1 2 Schweizer MT, Calvo M, Moreno V, Mellado B, Castellano D, Spira AI, et al. (2025). "Mevrometostat (PF-06821497), an enhancer of zeste homolog 2 (EZH2) inhibitor, in combination with enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC): A randomized dose-expansion study". Journal of Clinical Oncology. 43 (5_suppl) LBA138. doi:10.1200/JCO.2025.43.5_suppl.LBA138.
  3. Schweizer MT, Penkov K, Choudhury AD, Calvo E, Frank RC, Liu L, et al. (2024). "Phase 1 trial of mevrometostat (PF-06821497), a potent and selective inhibitor of enhancer of zeste homolog 2 (EZH2), in castration-resistant prostate cancer (CRPC)". Journal of Clinical Oncology. 42 (16_suppl): 5061. doi:10.1200/JCO.2024.42.16_suppl.5061.
  4. "SUO 2024: Mevrometostat (PF-06821497) in Combination with Enzalutamide in Patients with Metastatic Castration-Resistant Prostate Cancer Previously Treated with Abiraterone Acetate". UroToday. Retrieved 11 September 2025.
  5. "Mevrometostat and enzalutamide in mCRPC: gene expression and EZH2 modulation". VJ Oncology. 17 February 2025. Retrieved 11 September 2025.
  6. Pfizer (4 September 2025). A PHASE I DOSE ESCALATION AND EXPANDED COHORT STUDY OF PF 06821497 (MEVROMETOSTAT) IN THE TREATMENT OF ADULT PATIENTS WITH RELAPSED/REFRACTORY SMALL CELL LUNG CANCER (SCLC), CASTRATION RESISTANT PROSTATE CANCER (CRPC) AND FOLLICULAR LYMPHOMA (FL) (Report). clinicaltrials.gov.
  7. "ASCO GU 2025: Mevrometostat (PF-06821497), an EZH2 Inhibitor, in Combination with Enzalutamide in Patients with mCRPC". UroToday. Retrieved 11 September 2025.
  8. 1 2 "Mevrometostat/enzalutamide combo shows rPFS benefit in mCRPC". Urology Times. 21 February 2025. Retrieved 11 September 2025.
  9. Agarwal N, Schweizer MT, Castro E, Azad A, George DJ, Chakrabarti J, et al. (2025). "Mevrometostat (PF-06821497) in combination with enzalutamide in patients with metastatic castration-resistant prostate cancer previously treated with abiraterone acetate: The phase 3, randomized MEVPRO-1 study". Journal of Clinical Oncology. 43 (5_suppl) TPS288. doi:10.1200/JCO.2025.43.5_suppl.TPS288.
  10. Pfizer (4 September 2025). A PHASE 3, RANDOMIZED, OPEN-LABEL STUDY OF PF-06821497 (MEVROMETOSTAT) IN COMBINATION WITH ENZALUTAMIDE COMPARED WITH ENZALUTAMIDE OR DOCETAXEL IN PARTICIPANTS WITH METASTATIC CASTRATION RESISTANT PROSTATE CANCER PREVIOUSLY TREATED WITH ABIRATERONE ACETATE (MEVPRO-1) (Report). clinicaltrials.gov.
  11. "ASCO GU 2025: Mevrometostat (PF-06821497) in Combination With Enzalutamide for ARPI-Naïve Patients With mCRPC: The Phase 3, Randomized MEVPRO-2 Trial". UroToday. Retrieved 11 September 2025.
  12. Pfizer (4 September 2025). A PHASE 3, RANDOMIZED, DOUBLE BLIND, PLACEBO CONTROLLED STUDY OF PF-06821497 (MEVROMETOSTAT) WITH ENZALUTAMIDE IN METASTATIC CASTRATION RESISTANT PROSTATE CANCER (MEVPRO-2) (Report). clinicaltrials.gov.
  13. Pfizer (4 September 2025). A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of Mevrometostat (PF-06821497) With Enzalutamide in Metastatic Castration-Sensitive Prostate Cancer (MEVPRO-3) (Report). clinicaltrials.gov.
  14. "ASCO 2025: Mevrometostat in Combination with Enzalutamide in Patients with mCRPC Previously Treated with Abiraterone Acetate". UroToday. Retrieved 11 September 2025.
  15. "Mevrometostat Plus Enzalutamide Improves rPFS vs Enzalutamide in Metastatic CRPC". OncLive. 21 February 2025. Retrieved 11 September 2025.
  16. "ASCO 2025: Safety and Pharmacokinetics of Mevrometostat in Combination with Enzalutamide in Patients with mCRPC". UroToday. Retrieved 11 September 2025.