Background Bone metastases (BoM) are a negative prognostic factor in non-small-cell lung cancer (NSCLC). Beyond its supportive role, bone is a hematopoietic organ actively regulating immune system. We hypothesized that BoM may influence sensitivity to immunotherapy. Methods Pretreated non-squamous (cohort A) and squamous (cohort B) NSCLCs included in the Italian Expanded Access Program were evaluated for nivolumab efficacy according to BoM. Results Cohort A accounted for 1588 patients with non-squamous NSCLC, including 626 (39%) with (BoM+) and 962 (61%) without BoM (BoM-). Cohort B accounted for 371 patients with squamous histology including 120 BoM+ (32%) and 251 (68%) BoM- cases. BoM+ had lower overall response rate (ORR; Cohort A: 12% versus 23%, p < 0.0001; Cohort B: 13% versus 22%, p = 0.04), shorter progression free survival (PFS; Cohort A: 3.0 versus 4.0 months, p < 0.0001; Cohort B: 2.7 versus 5.2 months, p < 0.0001) and overall survival (OS; Cohort A: 7.4 versus 15.3 months, p < 0.0001; Cohort B: 5.0 versus 10.9 months, p < 0.0001). Moreover, BoM negatively affected outcome irrespective of performance status (PS; OS in both cohorts: p < 0.0001) and liver metastases (OS cohort A: p < 0.0001; OS Cohort B: p = 0.48). At multivariate analysis, BoM independently associated with higher risk of death (cohort A: HR 1.50; cohort B: HR 1.78). Conclusions BoM impairs immunotherapy efficacy. Accurate bone staging should be included in clinical trials with immunotherapy.

PURPOSE: The combination of encorafenib (BRAF inhibitor) plus binimetinib (MEK inhibitor) has demonstrated clinical efficacy with an acceptable safety profile in patients with BRAF^V600E/K-mutant metastatic melanoma. We evaluated the efficacy and safety of encorafenib plus binimetinib in patients with BRAF^V600E-mutant metastatic non–small-cell lung cancer (NSCLC). METHODS: In this ongoing, open-label, single-arm, phase II study (ClinicalTrials.gov identifier: NCT03915951 ), patients with BRAF^V600E-mutant metastatic NSCLC received oral encorafenib 450 mg once daily plus binimetinib 45 mg twice daily in 28-day cycles. The primary end point was confirmed objective response rate (ORR) by independent radiology review (IRR). Secondary end points included duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival, time to response, and safety. RESULTS: At data cutoff, 98 patients (59 treatment-naïve and 39 previously treated) with BRAF^V600E-mutant metastatic NSCLC received encorafenib plus binimetinib. Median duration of treatment was 9.2 months with encorafenib and 8.4 months with binimetinib. ORR by IRR was 75% (95% CI, 62 to 85) in treatment-naïve and 46% (95% CI, 30 to 63) in previously treated patients; median DOR was not estimable (NE; 95% CI, 23.1 to NE) and 16.7 months (95% CI, 7.4 to NE), respectively. DCR after 24 weeks was 64% in treatment-naïve and 41% in previously treated patients. Median PFS was NE (95% CI, 15.7 to NE) in treatment-naïve and 9.3 months (95% CI, 6.2 to NE) in previously treated patients. The most frequent treatment-related adverse events (TRAEs) were nausea (50%), diarrhea (43%), and fatigue (32%). TRAEs led to dose reductions in 24 (24%) and permanent discontinuation of encorafenib plus binimetinib in 15 (15%) patients. One grade 5 TRAE of intracranial hemorrhage was reported. Interactive visualization of the data presented in this article is available at the PHAROS dashboard ( https://clinical-trials.dimensions.ai/pharos/ ). CONCLUSION: For patients with treatment-naïve and previously treated BRAF^V600E-mutant metastatic NSCLC, encorafenib plus binimetinib showed a meaningful clinical benefit with a safety profile consistent with that observed in the approved indication in melanoma.