Background/Objectives: Cryotherapy is used for local tissue destruction through rapid freeze–thaw cycles. It induces cancer cell necrosis followed by inflammation in the treated tumor microenvironment, and it stimulates systemic adaptive immunity. Combining cryotherapy with immunotherapy may provide a sustained immune response by preventing T cell exhaustion. Methods: Fifty-five patients with metastatic non-small cell lung cancer who had received no prior treatment were randomized into two groups in a 1:1 ratio: the bronchoscopic cryotherapy group or the control group. Patients received up to four cycles of pembrolizumab as monotherapy or in combination with platinum-based chemotherapy. Immune-related adverse events (irAEs), complications, tumor size changes, overall response rate (ORR), and disease control rate (DCR) were evaluated. Results: Lung tumors, treated with cryotherapy, demonstrated continuous reduction from the baseline (22.4 cm² vs. 14.4 cm² vs. 10.2 cm², p < 0.001). Similar changes were observed in pulmonary tumors in the control group (19.0 cm² vs. 10.0 cm², p < 0.001). The median change in pulmonary tumors between two groups was not significant (−42.9% vs. −27.7%, p = 0.175). No significant differences were observed in the ORR (28.6% vs. 23.1%, p = 0.461) or target lesion decrease (−24.0% vs. −23.4%, p = 0.296) between the groups. However, the DCR was significantly higher in the cryotherapy group (95.2% vs. 73.1%, p = 0.049). No cases of serious bleeding during cryotherapy or pneumothorax were observed. Six patients (25.0%) in the cryotherapy group and eight (26.7%) in the control group experienced irAEs. Conclusions: Our study demonstrated that combined bronchoscopic cryotherapy and immunotherapy with or without chemotherapy may reduce the rate of progressive disease in metastatic non-small cell lung cancer patients while maintaining a satisfactory safety profile.

Bronchoscopic cryotherapy is routinely used for endobronchial tumor debulking, but may also exert systemic immunologic effects that could interact with immune checkpoint blockade. We investigated peripheral blood T-cell dynamics following bronchoscopic cryotherapy and subsequent pembrolizumab-based first-line therapy in metastatic non-small-cell lung cancer (NSCLC). In this prospective, randomized, controlled single-center study, patients with metastatic NSCLC were randomized into treatment groups of bronchoscopic cryotherapy performed 7 (±1) days before standard-of-care pembrolizumab (with or without platinum-based chemotherapy) or to standard-of-care therapy alone. Peripheral blood mononuclear cells were analyzed by flow cytometry at baseline, week 3, and week 6. Radiologic response was assessed using RECIST 1.1. Progression-free survival (PFS) and overall survival (OS) were evaluated using the Kaplan–Meier test and Cox regression. Flow cytometry was performed on 34 cryotherapy and 42 control patients. The cryotherapy group demonstrated a decrease in circulating CD4+ T cells (p = 0.002) and an increase in circulating CD8+ T cells (p = 0.013) by week 6. CD25+FOXP3+CD4+ Tregs decreased from baseline to week 3 (p = 0.024) and remained reduced through week 6. Overall response rate was higher in the cryotherapy group (41.2% vs. 16.7%; p = 0.022), while PFS and OS were numerically longer, although not statistically different (median PFS 9.5 vs. 5.3 months; median OS 17.6 vs. 14.8 months). The decrease in Tregs at week 3 was observed to predict better PFS. In patients with metastatic NSCLC receiving first-line pembrolizumab with or without chemotherapy, the addition of bronchoscopic cryotherapy was associated with a detectable peripheral immune remodeling and a higher objective response rate, whereas PFS and OS were numerically longer but not statistically different.

Background: Bronchoscopic cryotherapy may enhance anti-tumor immunity and improve the effect of immune checkpoint blockade, but CD8+ T cell dynamics after cryotherapy combined with pembrolizumab-based therapy in metastatic non-small cell lung cancer (NSCLC) remain insufficiently characterized. Methods: In this prospective, exploratory, randomized, controlled, single-center study, metastatic NSCLC patients were assigned to bronchoscopic cryotherapy performed 7 ± 1 days before first-line pembrolizumab-based therapy or to standard treatment alone. Peripheral blood mononuclear cells were analyzed by flow cytometry at baseline, week 3, and week 6. CD8+ T cell subsets defined by CD45RO, CD28, granzyme B (GzB), IFNγ, Ki-67, and PD-1 were evaluated in relation to treatment group, radiologic response, progression-free survival (PFS), and overall survival (OS). Results: Flow cytometry was performed in 76 patients, including 34 in the cryotherapy group and 42 in the control group. Cryotherapy was associated with a treatment-specific increase in circulating GzB+ CD8+ T cells by week 6. In contrast, Ki-67+ CD8+ and GzB+Ki-67+ cells increased in both treatment groups, suggesting that early peripheral CD8+ proliferation was largely shared across pembrolizumab-based therapy. Radiologic responders demonstrated more sustained proliferative CD8+ dynamics, most consistently reflected by increased CD28+ Ki-67+ cells. In exploratory landmark survival analyses, a higher week-3-to-baseline GzB+ Ki-67+ CD8+ ratio showed a hypothesis-generating association with longer PFS and OS. Conclusions: In metastatic NSCLC patients receiving first-line pembrolizumab-based therapy, the addition of bronchoscopic cryotherapy was associated with peripheral CD8+ T cell remodeling toward enhanced cytotoxic activity. Proliferative CD8+ T cell changes were associated with radiologic response and better survival. These findings support bronchoscopic cryotherapy as a potential immune-modulating adjunct and warrant validation in larger studies.