Supplementary Material for: Necitumumab plus Gemcitabine and Cisplatin as First-Line Therapy in Patients with Stage IV EGFR- Expressing Squamous Non-Small-Cell Lung Cancer: German Subgroup Data from an Open-Label, Randomized Controlled Phase 3 Study (SQUIRE)

Background: In the SQUIRE study, adding the antiepidermal
growth factor receptor (EGFR) IgG1 antibody
necitumumab to first-line gemcitabine and cisplatin
(GC + N) in advanced squamous non-small-cell lung cancer
(sqNSCLC) significantly improved overall survival
(OS); the safety profile was acceptable. We explored
data for the German subpopulation (N = 96) of SQUIRE
patients with EGFR-expressing tumors. Patient and
Methods: Patients with stage IV sqNSCLC were randomized
1:1 to up to 6 cycles of open-label GC + N or GC
alone. GC + N patients with no progression continued on
necitumumab monotherapy until disease progression or
intolerable toxicity. The primary endpoint was OS; the secondary endpoints included progression-free survival
(PFS), safety and health-related quality of life (EQ-5D,
Lung Cancer Symptom Scale (LCSS)). Results: The 96
German SQUIRE patients with EGFR-expressing tumors
(GC + N 42, GC 54) received a median of 4 GC cycles; the
GC + N patients received 5 cycles of necitumumab. Adding
necitumumab was associated with 41% risk reduction
of death (hazard ratio (HR) 0.59, 95% confidence
interval (CI) 0.37–0.94, p = 0.026) and 44% risk reduction
of progression (HR 0.56, 95% CI 0.33–0.95, p = 0.029). Adverse
events typically associated with EGFR antibody
treatment (including rash, hypomagnesemia) were more
common with GC + N. The time to deterioration of the
EQ-5D and LCSS scores showed no notable differences
between the treatment arms, except for appetite loss
(delayed for GC + N). Conclusion: The survival benefit
from adding necitumumab to first-line GC was more
pronounced in the German SQUIRE subpopulation with
EGFR-expressing tumors than in the overall (intentionto-treat)
population; toxicity was manageable and consistent
with the overall population.