β-glucan combined with Envafolimab and Endostar as immune rechallenge for metastatic non-small cell lung cancer

Immune checkpoint inhibitor rechallenge has emerged as a prominent study area in non-small cell lung cancer (NSCLC). β-glucan was reported to reverse resistance to anti-PD-1/PD-L1 inhibitors by regulating the tumor microenvironment. In this self-initiated clinical trial (ChiCTR2100054796), NSCLC participants who have previously failed anti-PD-1 therapy received β-glucan (500 mg, bid, d1-21), Envafolimab (300 mg, d1) and Endostar (210 mg, civ72h) every 3 weeks until disease progression or unacceptable toxicity. The clinical efficacy and adverse events were observed, while serum samples were collected for proteomic analysis. Twenty Three patients were enrolled from January 2022 to March 2023 (median age, 65 years; male, n = 18 [78.3%]; squamous NSCLC, n = 9 [39.1%]; mutant type, n = 13 [56.5%]). The overall response rate (ORR) was 21.7% and disease control rate (DCR) was 73.9%. Median progression-free survival (mPFS) and median overall survival (mOS) was 4.3 months [95% CI: 2.0–6.6] and 9.8 months [95% CI: 7.2–12.4], respectively. The mPFS between PD-L1 positive and negative subgroup has significant difference (6.3 months vs. 2.3 months, p = 0.002). Treatment-related adverse events (TRAEs) occurred in 52.2% of patients. The most common TRAEs were hypothyroidism (26.1%) and fatigue (26.1%). 2 (8.7%) grade 3 adverse events were reported. No adverse reaction related deaths have been observed. Proteomic analysis revealed that the levels of CASP-8, ARG1, MMP12, CD28 and CXCL5 correlated with resistance to the treatment while the levels of CD40-L and EGF related to the favorable response. β-glucan combined with Envafolimab and Endostar has considerable efficacy and safety for immune rechallenge in metastatic NSCLC patients who failed of anti-PD-1 treatment previously, especially for PD-L1 positive patients.