biopsy and tumor content.IB6 expression was determined by immunohistochemistry (IHC) at a central lab.IB6-expressing tumors had 1% of tumor cells with any staining intensity.IB6-high tumors had 50% of tumor cells with staining at IHC 2+ intensity.Results: In a 253-patient cohort, median age was 67 years.Overall, 51% were male, 56% were White, 80% received treatment at academic sites, 87% had stage III or IV disease at diagnosis, and 69% had nonsquamous histology.Of the tissue samples, 63% were from metastatic lesions, and 83% were taken on or after the diagnosis of metastatic disease.In the 227 patients with known IB6 IHC expression, 93% (95% CI, 89%-96%) of patients had IB6 expression on 1% of tumor cells with no significant difference by histology.IB6-high expression was observed in 77% (95% CI, 71%-82%) of samples and significantly varied by histology (81% 95% CI, 74%-87% in nonsquamous samples and 57% 95% CI, 41%-72% in squamous samples).Time between biopsy collection and staining (<5 vs 5 years) did not impact prevalence.Conclusions: This is an updated analysis of the first real-world study characterizing IB6 expression in mNSCLC.While the clinical implications of IB6 remain under investigation, these data suggest that IB6 may be a widely applicable therapeutic target, which warrants further exploration.
Agbarya et al. (Tue,) studied this question.