Safety and efficacy of PD-1 blockade-activated multiple antigen-specific cellular therapy alone or in combination with apatinib in patients with advanced solid tumors: a pooled analysis of two prospective trials

<p><strong>BACKGROUND: </strong>The lethal effects of multiple antigen-specific cellular therapy (MASCT) may be enhanced by blocking PD-1 in vitro and vascular endothelial growth factor receptor 2 inhibitor (apatinib). We analyzed the pooled data from our phase I/II trials to determine the toxicity and efficacy of PD-1 blockade (SHR-1210)-activated MASCT (aMASCT) alone or in combination with apatinib in advanced solid tumors.</p><p><strong>METHODS: </strong>Patients with advanced solid tumors received aMASCT alone (n = 32) or aMASCT plus apatinib (500 mg q.d., n = 38) after standard treatment. The safety profile was the primary end point. The secondary end points were antitumor response, progression-free survival (PFS), and overall survival (OS). The circulating T cells were quantified before and after aMASCT infusion.</p><p><strong>RESULTS: </strong>Treatment-related adverse events (AEs) occurred in 18/32 (56.3%) and 25/38 (65.8%) patients in the aMASCT and aMASCT plus apatinib groups, respectively. No serious AEs were reported, and apatinib did not increase immunotherapy-related toxicity. The objective response rate (34.2% and 18.8%) and PFS (median 6.0 and 4.5 months, P = 0.002) were improved in the aMASCT plus apatinib group compared with the aMASCT group; however, the OS was not improved (median 10.0 and 8.2 months, P = 0.098). Multivariate analyses indicated that two or more cycles of aMASCT treatment was an independent and favorable prognostic factor of PFS and OS. The circulating T cells increased and Tregs decreased in both groups after one cycle of aMASCT treatment.</p><p><strong>CONCLUSIONS: </strong>Treatment with aMASCT plus apatinib was safe and effective for the management of advanced solid tumors.</p>