Table 1.

Baseline biomarker status by treatment arm

Buparlisib + paclitaxel, N = 79Placebo + paclitaxel, N = 79All patients, N = 158
Biomarkeran (%)n (%)n (%)
Based on archival tumor tissue analysis
PIK3CA alteration
 Yes7 (11.7)9 (14.5)16 (13.1)
 No53 (88.3)53 (85.5)106 (86.9)
 Unknown/missing191736
PTEN loss of expression
 Yes1 (1.3)1 (1.3)2 (1.3)
 No74 (98.7)77 (98.7)151 (98.7)
 Unknown/missing415
PI3K pathway activation statusb
 Activated8 (13.8)10 (16.1)18 (15.0)
 Nonactivated50 (86.2)52 (83.9)102 (85.0)
 Unknown/missing211738
HPV status
 Positive17 (24.3)11 (15.1)28 (19.6)
 Negative53 (75.7)62 (84.9)115 (80.4)
 Unknown/missing9615
TP53 alteration
TP53 altered26 (57.8)26 (66.7)52 (61.9)
TP53 nonaltered19 (42.2)13 (33.3)32 (38.1)
 Unknown/missing344074
PD-L1 expression status
 <1%9 (28.1)15 (53.6)24 (40.0)
 ≥1%23 (71.9)13 (46.4)36 (60.0)
 Unknown/missing475198
Intratumoral TILs
 <10%41 (58.6)52 (71.2)93 (65.0)
 ≥10%29 (41.4)21 (28.8)50 (35.0)
 Unknown/missing9615
Stromal TILs
 <15%21 (30.4)31 (43.1)52 (36.9)
 ≥15%48 (69.6)41 (56.9)89 (63.1)
 Unknown/missing10717
Intratumoral CD8 expression
 <5%36 (58.1)41 (66.1)77 (62.1)
 ≥5%26 (41.9)21 (33.9)47 (37.9)
 Unknown/missing171734
Stromal CD8 expression
 <10%19 (31.1)26 (42.6)45 (36.9)
 ≥10%42 (68.9)35 (57.4)77 (63.1)
 Unknown/missing181836
CD8 expression in invasive margins
 <25%38 (69.1)38 (82.6)76 (75.2)
 ≥25%17 (30.9)8 (17.4)25 (24.8)
 Unknown/missing243357
Based on ctDNA analysis
HPV status
 Positive12 (22.6)11 (18.6)23 (20.5)
 Negative41 (77.4)48 (81.4)89 (79.5)
 Unknown/missing262046
TP53 alteration
TP53 altered18 (34.0)25 (42.4)43 (38.4)
TP53 nonaltered35 (66.0)34 (57.6)69 (61.6)
 Unknown/missing262046
Mutational load
 Low mutational load (<13 variants39 (75.6)47 (79.7)86 (76.8)
 High mutational load (≥13 variants)14 (26.4)12 (20.3)26 (23.2)
 Unknown/missing262046
  • Abbreviations: CD8, cluster of differentiation 8; PD-L1, programmed death ligand 1; PIK3CA, phosphatidylinositol 3-kinase catalytic subunit alpha; PTEN, phosphatase and tensin homolog; and TILs, tumor-infiltrating lymphocytes.

  • aFor each marker, frequencies of reported alterations were calculated based on patients with a valid biomarker data. The proportions of patients with unknown/missing status (excluded from the frequency calculation) are as follows: PIK3CA 22.8%; PTEN loss 3.2%; PI3K activation 24.1%; HPV in archival tumor 9.5%; TP53 alteration in archival tumor 46.8%; PD-L1 62%; intratumoral TILS 9.5%; stromal TILS 10.8%; intratumoral CD8 21.5%; stromal CD8 22.8%; CD8 in invasive margins 36.1%; HPV, TP53, and mutational load in ctDNA 29.1%.

  • bPI3K activation status was derived from PIK3CA mutation status and PTEN expression status. The PI3K status was considered activated if a PIK3CA alteration was identified and/or if PTEN expression was lost.