The following article features coverage from the ASCO Genitourinary Cancers Symposium 2022. Click here to read more of MPR‘s conference coverage.


Continued treatment with enzalutamide was found to be beneficial in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel plus prednisolone following disease progression on enzalutamide alone, according to findings presented at the 2022 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium.

The PRESIDE trial (ClinicalTrials Identifier: NCT02288247) included 687 chemotherapy-naïve patients with mCRPC who had progressive disease while on androgen deprivation therapy (ADT) or following bilateral orchiectomy. During the open-label part of the trial (Period 1; N=687), patients received enzalutamide in addition to ADT.

At week 13, all patients were assessed by prostate-specific antigen (PSA) and imaging.  Patients with confirmed disease progression were then eligible to receive either enzalutamide 160mg orally once daily with docetaxel and prednisolone or placebo with docetaxel and prednisolone, in addition to ADT (Period 2; n=271). The primary endpoint of Period 2 was progression free survival (PFS); time to PSA progression (TTPP; ≥25% increase; absolute increase ≥2ng/mL) was designated as a secondary endpoint.

Results showed that PFS was significantly improved in patients who continued treatment with enzalutamide compared with those who received placebo (hazard ratio [HR], 0.72; 95% CI, 0.53-0.96; P =.027). Median PFS was observed to be 9.53 months (95% CI, 8.25-10.87) in the enzalutamide arm and 8.28 months (95% CI, 6.28-8.71) in the placebo arm.

“[Enzalutamide] also significantly delayed TTPP (8.44 vs. 6.24 months with [placebo]; HR 0.58; 95% CI, 0.41-0.82; P =.002) and improved PSA response at any time ([enzalutamide], n=76 [55.9%]; [placebo], n=50 [37.0%]),” the investigators reported.

As for safety, 97.8% (n=133) and 97.0% (n=131) of patients in the enzalutamide and placebo groups had a treatment-emergent adverse event, respectively. The most common grade 4 treatment-emergent adverse event was neutropenia. Adverse events related to enzalutamide treatment were consistent with its known safety profile.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Merseburger AS, Attard G, Boysen G, et al. A randomized, double-blind, placebo (PBO)-controlled, phase 3b study of the efficacy and safety of continuing enzalutamide (ENZA) in chemotherapy-naïve, metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated with docetaxel (DOC) plus prednisolone (PDN) who have progressed on ENZA: PRESIDE. Presented at: ASCO GU 2022; February 17-19, 2022; Abstract 15.