Targeting of Focal Adhesion Kinase enhances the immunogenic cell death of PEGylated liposome doxorubicin to optimize therapeutic responses of immune checkpoint blockade

Focal adhesion kinase (FAK) is frequently amplified and acts as an immune modulator across cancer types. However, evidence illustrates that targeting FAK is most effective in combination therapy rather than in monotherapy. Here, we demonstrated that the FAK inhibitor, IN10018, and pegylated liposome doxorubicin (PLD) exerted effective antitumor activity preclinically and clinically (clinical trial ID: CTR20200913). The clinical study is a phase Ib trial which includes dose confirmation and expansion sections. The primary endpoint is objective response rate (ORR). Secondary endpoints include disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. As of the data cutoff date (30 November 2022), a total of 61 platinum-resistant ovarian cancer (PROC) patients were enrolled and no IN10018-related grade 4 or 5 adverse effects (AEs) were reported. The ORR was 46.3% (95% confidence interval (CI): 32.6%, 60.4%) and the DCR was 83.3% (95% CI: 70.7%, 92.1%). The median PFS was 7.26 months (95% CI: 5.16 - 8.02 months), and the median duration of response (DoR) was 6.93 months (95% CI: 4.17 - 9.13 months). The primary and secondary endpoints were met. The median OS was not reached, and still maturing. Notably, the regimen exhibited response latency and long-lasting effects in the clinical trial, outcomes frequently observed in immunotherapy. Our preclinical study revealed that the 2-drug combination can maximize the immunogenic cell death (ICD) of cancer cells, boosting the maturation of dendritic cells (DCs) and stimulating CD8 T cells to strengthen the antitumor effects. At present, immune checkpoint blockade (ICB) is widely considered to exert long-term treatment benefits by activating antitumor immunity. However, many cancer patients show poor clinical responses to ICB due in part to the lack of immunogenic niche. Our work confirmed that IN10018 in combination with PLD can prime the tumor microenvironment, supplementing it with sufficient tumor-infiltrating lymphocytes (TILs) to activate antitumor immunity. Correspondingly, animal studies validated that the antitumor effects of ICB can be significantly enhanced by this doublet regimen. The preclinical results warrant further clinical exploration for the triplet regimen with IN10018, PLD, and ICB. Overall design: Transcriptome profiling was performed to determine the mechanism of the observed clinical antitumor effects. In brief, the SK-OV-3 cells were treated with DMSO, 300 nM doxorubicin, 3 µM IN10018, and a combination of IN10018 and doxorubicin for 24 hours. The total mRNA was extracted for the RNA sequencing.