Antibody–drug conjugates (ADCs) have emerged as a transformative modality in the treatment of solid tumors. YL201, a novel B7H3-targeting ADC, leverages a tumor microenvironment activable linker-payload platform, coupled with a novel topoisomerase 1 inhibitor via a protease-cleavable linker. Here we report the findings from a large-scale, global, multicenter, phase 1 trial evaluating the safety, pharmacokinetics and preliminary efficacy of YL201 in patients with advanced solid tumors refractory to standard therapies. The trial included a dose-escalation part (phase 1) and a dose-expansion part (phase 1b). A total of 312 patients were enrolled across multiple tumor types, including extensive-stage small cell lung cancer (ES-SCLC), nasopharyngeal carcinoma (NPC), non-small cell lung cancer, esophageal squamous cell carcinoma and other solid tumors. The maximum tolerated dose was determined to be 2.8 mg kg⁻¹, and the recommended expansion dose was selected as 2.0 mg kg⁻¹ and 2.4 mg kg⁻¹ every 3 weeks. The most common grade 3 or higher treatment-related adverse events included neutropenia (31.7%), leukopenia (29.5%) and anemia (25.0%). Only 4 cases of interstitial lung disease (1.3%) and 1 case of infusion reactions (0.3%) were observed. Encouraging anti-tumor activity was observed, particularly in patients with ES-SCLC (objective response rate (ORR), 63.9%), NPC (ORR, 48.6%), lung adenocarcinoma (ORR, 28.6%) and lymphoepithelioma-like carcinoma (ORR, 54.2%). No significant correlation between B7H3 membrane expression and the ORR was found. YL201 demonstrated an acceptable safety profile and a promising efficacy in heavily pretreated patients with advanced solid tumors, particularly in those with ES-SCLC, NPC or lymphoepithelioma-like carcinoma. Phase 3 clinical trials for patients with SCLC and NPC have already been initiated. ClinicalTrials.gov identifiers: NCT05434234 and NCT06057922.

The response to immune checkpoint inhibitors (ICIs) monotherapy remains unsatisfactory in patients with NSCLC. Thus, combining ICIs with other potential modalities is of great significance to enhance the response of single drug alone. Here, we identified that HIF-1α inhibition was capable of promoting anti-tumor immunity in NSCLC. We applied NSCLC cell lines and mouse models to evaluate the synergy of combined HIF-1α inhibition and PD-1 blockade on tumor growth and the function of tumor infiltrating lymphocytes (TILs). Public datasets were utilized to investigate patients' prognosis based on expressions of HIF-1α and LOXL2 as well as EMT-associated markers and CD8⁺ TILs. Moreover, we explored the correlation between HIF-1α and LOXL2 levels and CD8⁺ TILs in tumor samples from patients with NSCLC by immunohistochemistry, as well as their association to patients' survival. In vitro, PX-478, an HIF-1α inhibitor, promoted tumor cell apoptosis induced by T cells when combined with ICIs. Furthermore, mice treated with PX-478 and anti-PD-1 antibodies exhibited a marked delay in tumor growth and prolonged survival, which correlated with increased TILs and granzyme B secretion. Besides, patients with high HIF-1α expression exhibited high levels of EMT-related markers and low TILs, indicating an immunosuppressive phenotype. Mechanistically, we observed that HIF-1α inhibition suppressed the EMT phenotypes induced by hypoxia and further alleviated tumor immunosuppression, which was related to blockage of HIF-1α/LOXL2 signaling pathway. In summary, we identified that HIF-1α inhibition could synergize with anti-PD-1 to impair tumor growth in vitro and in vivo. Our data suggest that HIF-1α inhibitors represent a promising treatment to enhance anti-tumor immunity and provide preclinical rationale to evaluate the combination of ICIs with HIF-1α inhibition clinically in NSCLC.

Background PD-1/PD-L1 blockade has received approval for clinical application due to its encouraging benefit with improving prognosis in selected populations. Unfortunately, the response to immunotherapy for many patients remains unsatisfactory. It remains a great challenge to generate potential combinations that will outperform single agents alone with regard to anti-tumor activity. Methods Using NSCLC cell lines and mouse models, we explored the effects of combined niclosamide and PD-L1 blockade on tumor growth and T cell function. Furthermore, we investigated the relationship between PD-L1 and p-STAT3 expression in tumor samples from patients with NSCLC using IHC, as well as their relationship to patient survival. Results In vitro, niclosamide, an antihelmintic drug, enhanced the cancer cell lysis mediated by T cells in the presence of PD-L1 blockade. Accordingly, mice treated with niclosamide and PD-L1 antibody showed significant delay in tumor growth and increased survival which were associated with the increase of tumor infiltrating T cells and granzyme B release. Importantly, we found niclosamide could decrease the expression of PD-L1 in both a concentration- and time-dependent manner in NSCLC cells, which was linked to the blockage of p-STAT3 binding to the promoter of PD-L1. Conclusions An enhancement of PD-L1 antibody by niclosamide was observed in inhibition of NSCLC growth in vitro and in vivo, which was involved in blockage of p-STAT3 binding to promoter of PD-L1 and finally downregulation of PD-L1 expression. These encourage the combination therapy of niclosamide and PD-1/PD-L1 blockade to be further studied in clinic.

This study aimed to evaluate the efficacy and safety of cadonilimab (anti PD-1 and CTLA-4 bispecific antibody) in patients with previously treated metastatic non-small-cell lung cancer (NSCLC). In this multicenter, open-label, phase Ib/II study, patients with previously treated NSCLC were enrolled in three different cohorts: Cohort A, patients who had failed previous platinum-based doublet chemotherapy and were immunotherapy naïve; Cohort B, patients who had failed previous platinum-based doublet chemotherapy and had primary resistance to immunotherapy (IO); Cohort C, patients who had failed previous platinum-based doublet chemotherapy and had acquired resistance to IO. Eligible patients were given cadonilimab 6 mg/kg intravenously every 2 weeks. The primary endpoint was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors version 1.1. A total of 53 patients were enrolled: including 30 patients in cohort A, 7 in cohort B, and 16 in cohort C. ORR was 10% in cohort A, and there were no responder in cohort B and cohort C. Median overall survival was 19.61 (95% CI 11.30-NE) months, 4.93 (95% CI 1.97-NE) months and 13.16 (95% CI 6.18-NE) months in cohort A, B and C, respectively. Grade 3-4 treatment-related adverse events were reported in 6 (11.3 %) patients, including alanine aminotransferase increased (1.9%), rash (1.9%), chest discomfort (1.9%), hypercalcaemia (1.9%), anaemia (1.9%) and infusion related reaction (1.9%). The study did not meet its primary endpoint. Cadonilimab demonstrated limited efficacy in patients with IO failure, especially in cases of primary resistance. However, cadonilimab might play a role as a second-line immune monotherapy after platinum-based doublet chemotherapy failure and IO naïve, as its efficacy is similar to other immune checkpoint inhibitors after first-line chemotherapy. Cadonilimab was well-tolerated with mild toxicity, making it a potential candidate for the combination strategy. Clinical trial number NCT04172454.