Mevrometostat, an experimental EZH2 inhibitor, is showing strong potential for treating metastatic castration-resistant prostate cancer by blocking “lineage plasticity,” a process that allows cancer cells to change and resist hormone therapy. When combined with enzalutamide, the treatment significantly improved outcomes in early studies.
In a phase 1 trial, the combination nearly doubled median radiographic progression-free survival to 14.3 months, compared to 6.2 months with enzalutamide alone. Around 34–40% of patients experienced a 50% drop in PSA levels, and the risk of disease progression was reduced by about half. These results suggest the therapy may be effective even in patients with resistant disease.
Side effects such as diarrhea and low platelet counts were seen, but researchers improved safety by adjusting dosing with food, allowing lower doses with similar effectiveness. Based on these findings, two global phase 3 trials, MEVPRO-1 and MEVPRO-2, are now underway to confirm the benefits and potentially establish a new treatment approach.