Mifeprex (mifepristone)

P4, N=100, Recruiting, University of California, San Francisco

Emerging evidence suggests aberrant progesterone signalling contributes to TNBC risk, while preclinical studies indicate progesterone receptor modulators such as mifepristone may substantially reduce cancer development. DNA methylation-based markers reflecting field cancerization and replicative age could enable real-time monitoring of preventive efficacy and support an individualised primary prevention approach.

P1, N=20, Completed, Nova Southeastern University | Active, not recruiting --> Completed

P3, N=615, Active, not recruiting, Leiden University Medical Center | Recruiting --> Active, not recruiting | N=1186 --> 615 | Trial completion date: Apr 2030 --> Jan 2028 | Trial primary completion date: Apr 2029 --> Jun 2027

To explore P4-induced metabolic changes before and after the onset of HGSC, we analyzed serum samples from DKO mice treated with P4 or mifepristone, an inhibitor of P4 signaling, at premalignant and early tumor stages. Conversely, at this same stage, the targeted dataset showed notable increases in estrogens and glucocorticoids, while higher corticosterone levels were detected as HGSC began to develop. Overall, this study highlights the disruption of specific metabolites, phospholipid classes, and steroid hormones, in relation to HGSC tumor development under P4 treatment, suggesting their potential roles in OC development.

P=N/A, N=637, Completed, University of California, San Francisco

In vivo, ACC-bearing mice were treated with immune checkpoint inhibitors and mifepristone...Moreover, the percentage of macrophages detected by immunohistochemistry positively correlated with response to immunotherapy. Collectively, this study identifies a glucocorticoid-induced C1Q+ CD163 + macrophage phenotype that may contribute to T cell recruitment and enhance the efficacy of immunotherapy in ACC.

P=N/A, N=108, Completed, Affiliated Hospital of Nantong University; Affiliated Hospital of Nantong University | Not yet recruiting --> Completed

These findings demonstrate that M. longistyla extract possesses significant anti-hemorrhagic activity evidenced by reduced uterine bleeding, suppression of pro-inflammatory cytokine (TNF-α) and upregulation of VEGF. These effects suggest that the extract promotes endometrial repair and restoration of uterine homeostasis.

P3, N=1000, Not yet recruiting, University of Pennsylvania

Short-term mifepristone exposure does not produce molecular changes linked to endometrial carcinogenesis in BRCA1/2 pathogenic variant carriers. These findings provide important safety data for the future development of progesterone receptor modulators in cancer prevention. Long-term studies are needed to confirm these observations.

Mifepristone provided marked palliative benefit in this patient with nPR-negative, metastatic breast cancer, suggesting potential therapeutic value in similar cases. Confirmation of efficacy will require larger studies focused on tumors with absent or minimal nuclear progesterone receptor expression.