Table 2 Efficacy outcomes of phase 3 trials evaluating NHTs (Asian sub-analyses and the landmark studies)

Abiraterone acetate

mCNPC

LATITUDE^a Japanese subgroup analysis (n = 70) [36, 37]

OS, rPFS

Median follow-up time: 56.6 months (range 2.5–64.2)

Median OS NR

Overall 5-year survival rate: 69.2% (AAP) versus 53.7% (placebo)

Median rPFS: NR (AAP) versus 22 months (placebo) (HR 0.219; 95% CI 0.086–0.560)

Median follow-up time: 51.8 months (interquartile range 47.15–57.03)

Median OS: 53.3 months (95% CI 48.2–NR) (AAP) versus 36.5 (95% CI 33.5–40.0) months (placebo) (HR 0.66; 95% CI 0.56–0.78; p < 0.0001) [5]

Median rPFS was 33 months (AAP) versus 14.8 months (placebo); (HR 0.47; 95% CI 0.39–0.55; p < 0.001) [5]

Enzalutamide

mCNPC

ARCHES^b Japanese subgroup analysis (n = 92) [38]

rPFS

Median follow-up time: 15.7 months (enzalutamide) versus 15.5 months (placebo)

Risk of radiographic progression or death reduced by 61% versus placebo (HR 0.39; 95% CI 0.13–1.18)

Median follow-up time: 44.6 months

Survival extended versus placebo (HR 0.66; 95% CI 0.53–0.81; p < 0.0001) [8]

nmCRPC

PROSPER^c subgroup analysis by region (Asia vs. North America) [39]

OS

Median follow-up time: Not reported

OS benefit similar across Asia and North America (HR 1.164 [95% CI 0.824, 1.644; p = 0.3883])

Median follow-up time: ~ 48 months

Median OS: 67.0 months (95% CI 64.0-NR) (enzalutamide) versus 56.3 months (95% CI 54.4–63.0) (placebo) [10]

mCRPC

PREVAIL^d Asian subpopulation (Japan, Korea, and Singapore) (n = 148) [40]

rPFS, OS

Median follow-up time: Not reported

rPFS HR 0.38 (95% CI 0.10–1.44)

OS HR 0.59 (95% CI 0.29–1.23) OS not reached

Median follow-up time: 69 months

Median OS: 36 months (95% CI 34–38) (enzalutamide) versus 31 months (95% CI 29–34) (placebo) [11]

Apalutamide

mCNPC

TITAN^e Japanese subgroup analysis (n = 51) [42]

OS, rPFS

Median follow-up time for OS: 25.72 months (range 5.8–31.4)

OS: HR 0.840 (95% CI 0.210–3.361; p = 0.805)

Median follow-up time for rPFS: 22.05 months (range 1.1–29.3)

rPFS: HR 0.712 (95% CI 0.205–2.466; p = 0.59)

Median follow-up time: 44.0 months

Median OS NR (apalutamide) versus 52.2 months (placebo) (HR 0.65; 95% CI 0.53–0.79; p < 0.0001) [12]

rPFS: HR 0.48 (95% CI 0.39–0.60; p < 0.001) [12]

24-month rPFS: 68.2% (apalutamide) versus 47.5% (placebo) (HR 0.484; 95% CI 0.391–0.600; p < 0.001) [41]

TITAN^e East Asia subgroup analysis (China, Japan and Korea) (n = 62) [41]

rPFS, OS

Median follow-up time: 21.2 months (range 1.0–33.0) (apalutamide) versus 20.3 months (range 4.6–32.1) (placebo)

24-month rPFS: 76.1% (apalutamide) versus 52.3% (placebo) (HR 0.506; 95% CI 0.302–0.849; p = 0.009)

nmCRPC

SPARTAN^f Asian subpopulation (Japan, Taiwan, and South Korea) analysis (n = 126) [44]

MFS, PSA

Median follow-up time: Not reported

MFS improvement was similar for Asian patients (HR 0.29; p < 0.001) and non-Asian patients (HR 0.28; p < 0.0001)

PSA response: 82% (Asian patients) versus 91% (non-Asian patients)

Median follow-up time: Not reported

Patients with PSA not declined to < 0.2 ng/mL had a 54% risk reduction for MFS (HR 0.46; 95% CI 0.37–0.57; p < 0.0001), whereas patients with PSA that declined to < 0.2 ng/mL had an 88% risk reduction for MFS (HR 0.12, p < 0.0001) [43]

Median follow-up time: 52.0 months

PSA progression: HR 0.07 (95% CI 0.06–0.09; 95% CI 0.08–0.17; nominal p < 0.0001) [13]

SPARTAN^f Japanese subpopulation analysis (n = 55) [45]

MFS

Median treatment duration: 5.7 months (apalutamide) versus 11.0 months (placebo)

Median MFS: NR (95% CI 10.97-NE) (apalutamide) versus 18.23 months (95% CI 11.04–18.50) (placebo)

Darolutamide

nmCRPC

ARAMIS^g Japanese subpopulation analysis (n = 95) [47]

MFS

Median treatment duration: 14.8 months (darolutamide) versus 10.9 months (placebo)

Median MFS: NR (darolutamide) versus 18.2 months (placebo) (HR 0.28; 95% CI 0.11–0.70)

Median follow-up time: 29.0 months [6]

Median MFS: 40.4 months (darolutamide) versus 18.4 months (placebo) (HR 0.41; 95% CI 0.34–0.50; 2-sided p < 0.0001) [46]