Table 2.
Baseline characteristics of the 44 patients evaluable for the primary end point
| Imgatuzumab | Imgatuzumab | Cetuximab | |
|---|---|---|---|
| 700 mg (N = 15) | 1400 mg (N = 14) | 400/250 mg (N = 15)a | |
| Age, years (range) | 57 (45–68) | 62 (52–69) | 62 (42–74) |
| Gender (male/female) | 11/4 | 14/0 | 13/2 |
| ECOG-PS status (0/1/2) | 7/7/0b | 3/11/0 | 5/9/1 |
| Number of infusions (2/3/4) | 10/3/2 | 11/2/1 | 12/1/2 |
| FcyRIII genotype (GG/TG/TT) | 2/2/3 | −/-/- | −/2/2 |
| Stage (2/3/4) | 1/3/10b | 0/2/12 | 2/1/12 |
| TN stage | |||
| T1/T2/T3/T4/Tx | 3/1/0/8/1c | 0/4/1/9/0 | 0/4/1/10/0 |
| N0/N1/N2 | 1/7/5c | 6/0/8 | 6/0/9 |
| Tumor location (O/P/L) | 13/2/0 | 8/5/1 | 8/4/3 |
| Tumor size (mm), median (range) | 41 (22–70) | 50 (22–150) | 57 (22–100) |
| Tumor size, n (%) | |||
| ≤ 4 cm | 7 (46%) | 4 (29%) | 5 (35%) |
| > 4 cm | 8 (54%) | 10 (71%) | 9 (65%)d |
| HPV status (+/-/ND)e | 2/7/3 | 4/3/4 | 3/5/7 |
| Oncocarta Panel V1 mutationsf | 1 | 3 | 0 |
| Immune cell infiltration and EGFR/pERK levels [median positive cells/mm2 (range)]g | |||
| CD3 (T-lymphocyte) | 695 (83–1372) | 261 (68–1538) | 261 (73–821) |
| CD4 (T-helper cell) | 349 (27–825) | 197 (58–868) | 252 (68–812) |
| CD8 (T-cytotoxic cell) | 500 (24–892) | 158 (21–468) | 141 (30–441) |
| CD16 (NK, FcγRIII) | 732 (299–1261) | 235 (43–464) | 340 (94–948) |
| CD56 (NK cell) | 5 (0–150) | 7 (0–94) | 17 (0–77) |
| NKp46 (NK cell) | 34 (0–291) | 38 (4–137) | 17 (0–175) |
| CD68 (macrophage) | 501 (176–1222) | 177 (38–551) | 248 (75–538) |
| EGFR [H-score] | 184 (28–297) | 178 (62–227) | 174 (90–294) |
| pERK [H-score] | 111 (23–195) | 97 (44–183) | 120 (29–187) |
| CD3+/PERF + (cytotoxic T cells)h | 10.5 (0–48) | 25 (1–390) | 19 (0–304) |
| CD3-/PERF + (cytotoxic non T cells, NKs)h | 10 (0–35) | 7 (0–56) | 12 (0–244) |
| CD3-/CD56 + (NK cells)h | 13 (0–42) | 8 (0–26) | 2.5 (0–38) |
| CD16+/CD56 + (CD16+ NK cells)h | 12 (2–64) | 5 (0–11) | 4 (0–32) |
| CD68+/MHCII + (M1 macrophages)h | 158 (64–720) | 99 (38–280) | 160 (42–256) |
Cetuximab given at 400 mg/m2 for the first dose and 250 mg/m2 for the second dose.
Data missing for one patient.
Data missing for two patients.
Tumor size not given for one patient.
HPV status (genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 66) was assessed on DNA extracted from tumor material (pre-surgery and surgery material). HPV status not available for all patients; HPV cases were randomly distributed across arms with no apparent association with a change from baseline in SUVmax.
700-mg imgatuzumab: one tumor had a PIK3CA E545K mutation, 1400-mg imgatuzumab: one tumor had a MET R970C mutation and two tumors had PIK3CA H1047R mutations. Only local PET SUVmax data were available for all four cases, with response ranging from –46.75 to –78.30%.
Values represent the median number of positively stained cells per mm2 tumor area (range). For EGFR and pERK, the values represent the median H-score (range). Multiple fields of view were examined. Bold text indicates values that were imbalanced between study arms.
Duplex staining results were not available for all patients (imgatuzumab 700 mg: N = 8–13, imgatuzumab 1400 mg: N = 11–13, cetuximab 400/250 mg: N = 10–14).
CD, cluster of differentiation; ECOG-PS, Eastern Cooperative Oncology Group-performance status; EGFR, epidermal growth factor receptor; FcγR, Fcγ receptor; GG/TG/TT, guanine-guanine/thymine-guanine/thymine-thymine; HPV, human papilloma virus; mAb, monoclonal antibody; MHC, major histocompatibility complex; ND, not diagnostic; NK, natural killer; O/P/L, oral cavity/pharynx/larynx; PERF, perforin; pERK, phosphorylated extracellular signal-regulated kinase; PET, positron emission tomography; SUVmax, maximum standardized uptake value.