SHR3680, an investigational oral androgen receptor inhibitor (ARI), may be more effective than the first-generation ARI bicalutamide in patients with high-volume metastatic hormone-sensitive prostate cancer (mHSPC), according to research presented at the 2022 ASCO Annual Meeting.

SHR3680 plus androgen deprivation therapy (ADT) improved radiographic progression-free survival (rPFS) and overall survival (OS), when compared with bicalutamide plus ADT.

These results come from the phase 3 CHART trial (NCT03520478), which included 654 adults with mHSPC who had high-volume disease or visceral metastasis. 


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Patients were randomly assigned to receive SHR3680 at a dosage of 240 mg/day (n=326) or bicalutamide at a dosage of 50 mg/day (n=328), each in combination with ADT. Both groups had a median age of 69 years at baseline. 

At a data cutoff of February 28, 2022, SHR3680 significantly prolonged rPFS and OS, reported principal investigator Ding-Wei Ye, MD, PhD, of Fudan University Shanghai Cancer Center in China. 

The median rPFS was not reached in the SHR3680 arm and was 23.5 months in the bicalutamide arm (hazard ratio [HR], 0.46; 95% CI, 0.36-0.60). The median OS was not reached in either arm (HR, 0.58; 95% CI, 0.44-0.77; P =.0001).

All secondary efficacy endpoints favored SHR3680 plus ADT, according to the investigators. The median time to PSA progression was 11 months in the bicalutamide arm and not reached in the SHR3680 arm (HR 0.21; 95% CI, 0.16-0.27). 

The median time to the next skeletal-related event was 38.7 months in the bicalutamide arm and not reached in the SHR3680 arm (HR 0.65; 95% CI, 0.50-0.84). 

The median time to initiation of a new prostate cancer therapy was 15.2 months in the bicalutamide arm and not reached in the SHR3680 arm (HR 0.33; 95% CI, 0.26-0.41).

The treatment arms had similar frequencies of adverse events of any grade due to any cause (98.1% for each group). Grade 3 or higher treatment-related adverse events occurred in 20.7% of patients in the SHR3680 arm and 14.5% in the bicalutamide arm. 

Disclosures: This research was supported by Jiangsu Hengrui Pharmaceuticals. Some study authors reported being employed by the company. Please see the original reference for a full list of disclosures.

Reference

Ye DW, Gu W, Han W, et al. A phase 3 trial of SHR3630 versus bicalutamide in combination with androgen deprivation therapy (ADT) in patients with high-volume metastatic hormone-sensitive prostate cancer (mHSPC). Presented at ASCO 2022; June 3-7, 2022. Abstract 5005.

This article originally appeared on Cancer Therapy Advisor