Table 1.

Baseline patient and disease characteristics by baseline tumor size

FactorN (%a)BTS below median, n/N (%)BTS above median, n/N (%)P
Total583 (100)292/583 (50)291/583 (50)
Traditional factors
 ECOG PS
  0387 (66)224/387 (58)163/387 (42)<0.001
  1195 (34)68/195 (35)127/195 (65)
 LDH level
  Normal333 (58)226/333 (68)107/333 (32)<0.001
  Elevated238 (42)63/238 (27)175/238 (74)
 M stage
  M0, M1a, or M1b119 (20)96/119 (81)23/119 (19)<0.001
  M1c464 (80)196/464 (42)268/464 (58)
 Age
  Below median (≤61 years)298 (51)134/298 (45)164/298 (55)0.012
  Above median (>61 years)285 (49)158/285 (55)127/285 (45)
 Sex
  Male365 (63)179/365 (49)186/365 (51)0.514
  Female218 (37)113/218 (52)105/218 (48)
Other factors
BRAFV600 mutation status
  Mutant133 (23)66/133 (50)67/133 (50)0.976
  Wild type444 (77)221/444 (50)223/444 (50)
 Prior brain metastases
  Yes50 (9)31/50 (62)19/50 (38)0.076
  No532 (91)260/532 (49)272/532 (51)
 Prior ipilimumab treatment
  Naïve278 (48)155/278 (56)123/278 (44)0.009
  Exposed305 (52)137/305 (45)168/305 (55)
 Number of prior therapies
  0137 (23)77/137 (56)60/137 (44)0.102
  ≥1446 (77)215/446 (48)231/446 (52)
 Pembrolizumab dose and schedule
  10 mg/kg Q2W168 (29)92/168 (55)76/168 (45)0.329
  10 mg/kg Q3W272 (47)133/272 (49)139/272 (51)
  2 mg/kg Q3W143 (25)67/143 (47)76/143 (53)
 Tumor PD-L1 status
  Positive353 (77)175/353 (50)178/353 (50)0.925
  Negative106 (23)52/106 (49)54/106 (51)
 Site of metastasis
  Lung only84 (14)74/84 (88)10/84 (12)<0.001
  Liver, with or without any other sites201 (34)62/201 (31)139/201 (69)
  Other298 (51)156/298 (52)142/298 (48)
  • Abbreviations: Q2W, every 2 weeks; Q3W, every 3 weeks.

  • aPercentages calculated by using the number of patients with available data for each baseline characteristic as the denominator (may be <583 patients for some characteristics).