|The following article features coverage from the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
TAK-700 plus androgen deprivation therapy (ADT) did not provide an overall survival (OS) benefit when compared with bicalutamide plus ADT in patients with metastatic hormone-sensitive prostate cancer (mHSPC) enrolled in the phase 3 SWOG S1216 trial.
Results of the trial (ClinicalTrials.gov Identifier: NCT01809691) were presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting by Neeraj Agarwal, MD, of the University of Utah in Salt Lake City.
Dr Agarwal explained that TAK-700 is a 17,20-lyase inhibitor that may have the advantage of not requiring concomitant treatment with prednisone.
For this study, Dr Agarwal and colleagues randomly assigned 1279 mHSPC patients to receive ADT plus TAK-700 (n = 638) or ADT plus bicalutamide (n = 641). The study’s primary endpoint was OS, and secondary endpoints included progression-free survival (PFS), prostate-specific antigen (PSA) level at 7 months, and safety.
At baseline, the patients’ median age was about 68 years in both arms, 84% of patients were White, and extensive disease was present in 49% of patients. The median PSA level was 27.2 ng/mL in the TAK-700 arm and 31.8 ng/mL in the bicalutamide arm. Gleason scores of 8 or higher were seen in 58% and 60% of patients, respectively.
At a median follow-up of 4.9 years, 30.1% of patients in the TAK-700 arm and 15.6% in the bicalutamide arm were still on treatment.
The PSA response rate at 7 months was significantly better in the TAK-700 arm. The complete response rate (PSA ≤ 0.2 ng/mL) was 58% in the TAK-700 arm and 44% in the bicalutamide arm (P <.0001).
Similarly, the median PFS was significantly better in the TAK-700 arm than in the bicalutamide arm — 47.6 months and 23.0 months, respectively (hazard ratio [HR], 0.58; 95% CI, 0.51-0.67; P <.0001).
However, this did not translate to a significant benefit in OS. The median OS was 81.1 months with TAK-700 and 70.2 months with bicalutamide (HR, 0.86; 95% CI, 0.72-1.02; P =.04).
“Remarkably, the OS in the control arm far exceeded our estimate of 54 months by more than 16 months,” Dr Agarwal said.
Grade 3-5 adverse events that were more common with TAK-700 than with bicalutamide were hypertension (20% vs 4.5%) and fatigue (5% vs 1.7%). There were 7 grade 5 events — 5 in the TAK-700 arm and 2 in the bicalutamide arm.
Disclosures: This research was supported by Millennium Pharmaceuticals, Inc., and the National Cancer Institute. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Read more of Cancer Therapy Advisor’s coverage of the 2021 ASCO Annual Meeting by visiting the conference page.
Agarwal N, Tangen C, Hussain MHA, et al. SWOG S1216: A phase III randomized trial comparing androgen deprivation therapy (ADT) plus TAK-700 with ADT plus bicalutamide in patients (pts) with newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC) (NCT01809691). J Clin Oncol. 2021;39:(suppl 15; abstr 5001). doi:10.1200/JCO.2021.39.15_suppl.5001