Evaluation of tumour vaccine immunotherapy for the treatment of advanced non-small cell lung cancer: a systematic meta-analysis

Utility of cell-based vaccines as cancer therapy: Systematic review and meta-analysis

Cell-based therapeutic cancer vaccines use autologous patient-derived tumor cells, allogeneic cancer cell lines or autologous antigen presenting cells to mimic the natural immune process and stimulate an adaptive immune response against tumor antigens. The primary objective of this study is to perform a systematic literature review with an embedded meta-analysis of all published Phase 2 and 3 clinical trials of cell-based cancer vaccines in human subjects. The secondary objective of this study is to review trials demonstrating biological activity of cell-based cancer vaccines that could uncover additional hypotheses, which could be used in the design of future studies. We performed the systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The final review included 36 studies - 16 single-arm studies, and 20 controlled trials. Our systematic review of the existing literature revealed largely negative trials and our meta-analysis did not show evidence of clinical benefit from cell-based cancer-vaccines. However, as we looked beyond the stringent inclusion criteria of our systematic review, we identified significant examples of biological activity of cell-based cancer vaccines that are worth highlighting. In conclusion, the existing literature on cell-based cancer vaccines is highly variable in terms of cancer type, vaccine therapies and the clinical setting with no overall statistically significant clinical benefit, but there are individual successes that represent the promise of this approach. As cell-based vaccine technology continues to evolve, future studies can perhaps fulfill the potential that this exciting field of anti-cancer therapy holds.

Therapeutic vaccines for advanced non-small cell lung cancer

BACKGROUND

New strategies in immunotherapy with specific antigens that trigger an anti-tumour immune response in people with lung cancer open the possibility of developing therapeutic vaccines aimed at boosting the adaptive immune response against cancer cells.

OBJECTIVES

To evaluate the effectiveness and safety of different types of therapeutic vaccines for people with advanced non-small cell lung cancer.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Wanfang Data, and China Journal Net (CNKI) up to 22 August 2023.

SELECTION CRITERIA

We included parallel-group, randomised controlled trials evaluating a therapeutic cancer vaccine, alone or in combination with other treatments, in adults (> 18 years) with advanced non-small cell lung cancer (NSCLC), whatever the line of treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were overall survival, progression-free survival, and serious adverse events; secondary outcomes were three- and five-year survival rates and health-related quality of life.

MAIN RESULTS

We included 10 studies with 2177 participants. The outcome analyses included only 2045 participants (1401 men and 644 women). The certainty of the evidence varied by vaccine and outcome, and ranged from moderate to very low. We report only the results for primary outcomes here. TG4010 The addition of the vector-based vaccine, TG4010, to chemotherapy, compared with chemotherapy alone in first-line treatment, may result in little to no difference in overall survival (hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.65 to 1.05; 2 studies, 370 participants; low-certainty evidence). It may increase progression-free survival slightly (HR 0.74, 95% CI 0.55 to 0.99; 1 study, 222 participants; low-certainty evidence). It may result in little to no difference in the proportion of participants with at least one serious treatment-related adverse event, but the evidence is very uncertain (risk ratio (RR) 0.70, 95% CI 0.23 to 2.19; 2 studies, 362 participants; very low-certainty evidence). Epidermal growth factor vaccine Epidermal growth factor vaccine, compared to best supportive care as switch maintenance treatment after first-line chemotherapy, may result in little to no difference in overall survival (HR 0.82, 95% CI 0.66 to 1.02; 1 study, 378 participants; low-certainty evidence), and in the proportion of participants with at least one serious treatment-related adverse event (RR 1.32, 95% CI 0.88 to 1.98; 2 studies, 458 participants; low-certainty evidence). hTERT (vx-001) The hTERT (vx-001) vaccine compared to placebo as maintenance treatment after first-line chemotherapy may result in little to no difference in overall survival (HR 0.97, 95% CI 0.70 to 1.34; 1 study, 190 participants). Racotumomab Racotumomab compared to placebo as a switch maintenance treatment post-chemotherapy was assessed in one study with 176 participants. It may increase overall survival (HR 0.63, 95% CI 0.46 to 0.87). It may make little to no difference in progression-free survival (HR 0.73, 95% CI 0.53 to 1.00) and in the proportion of people with at least one serious treatment-related adverse event (RR 1.03, 95% CI 0.15 to 7.18). Racotumomab versus docetaxel as switch maintenance therapy post-chemotherapy was assessed in one study with 145 participants. The study did not report hazard rates on overall survival or progression-free survival time, but the difference in median survival times was very small - less than one month. Racotumomab may result in little to no difference in the proportion of people with at least one serious treatment-related adverse event compared with docetaxel (RR 0.89, 95% CI 0.44 to 1.83). Personalised peptide vaccine Personalised peptide vaccine plus docetaxel compared to docetaxel plus placebo post-chemotherapy treatment may result in little to no difference in overall survival (HR 0.80, 95% CI 0.42 to 1.52) and progression-free survival (HR 0.78, 95% CI 0.43 to 1.42). OSE2101 The OSE2101 vaccine compared with chemotherapy, after chemotherapy or immunotherapy, was assessed in one study with 219 participants. It may result in little to no difference in overall survival (HR 0.86, 95% CI 0.62 to 1.19). It may result in a small difference in the proportion of people with at least one serious treatment-related adverse event (RR 0.95, 95% CI 0.91 to 0.99). SRL172 The SRL172 vaccine of killed Mycobacterium vaccae, added to chemotherapy, compared to chemotherapy alone, may result in no difference in overall survival, and may increase the proportion of people with at least one serious treatment-related adverse event (RR 2.07, 95% CI 1.76 to 2.43; 351 participants).

AUTHORS' CONCLUSIONS

Adding a vaccine resulted in no differences in overall survival, except for racotumomab, which showed some improvement compared to placebo, but the difference in median survival time was very small (1.4 months) and the study only included 176 participants. Regarding progression-free survival, we observed no differences between the compared treatments, except for TG4010, which may increase progression-free survival slightly. There were no differences between the compared treatments in serious treatment-related adverse events, except for SRL172 (killed Mycobacterium vaccae) added to chemotherapy, which was associated with an increase in the proportion of participants with at least one serious treatment-related adverse event, and OSE2101, which may decrease slightly the proportion of people having at least one serious treatment-related adverse event. These conclusions should be interpreted cautiously, as the very low- to moderate-certainty evidence prevents drawing solid conclusions: many vaccines were evaluated in a single study with small numbers of participants and events.

Efficacy and Safety of Antigen-specific Immunotherapy in the Treatment of Patients with Non-small-cell Lung Cancer: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

We performed this systematic review and meta-analysis to assess the efficacy and safety of antigen-specific immunotherapy (Belagenpumatucel-L, MAGE-A3, L-BLP25, and TG4010) in the treatment of patients with non-small-cell lung cancer (NSCLC).

METHODS

A comprehensive literature search on PubMed, Embase, and Web of Science was conducted. Eligible studies were clinical trials of patients with NSCLC who received the antigenspecific immunotherapy. Pooled hazard ratios (HRs) with 95% confidence intervals (95%CIs) were calculated for overall survival (OS), progression-free survival (PFS). Pooled risk ratios (RRs) were calculated for overall response rate (ORR) and the incidence of adverse events.

RESULTS

In total, six randomized controlled trials (RCTs) with 4,806 patients were included. Pooled results showed that, antigen-specific immunotherapy did not significantly prolong OS (HR=0.92, 95%CI: 0.83, 1.01; P=0.087) and PFS (HR=0.93, 95%CI: 0.85, 1.01; P=0.088), but improved ORR (RR=1.72, 95%CI: 1.11, 2.68; P=0.016). Subgroup analysis based on treatment agents showed that, tecemotide was associated with a significant improvement in OS (HR=0.85, 95%CI: 0.74, 0.99; P=0.03) and PFS (HR=0.70, 95%CI: 0.49, 0.99, P=0.044); TG4010 was associated with an improvement in PFS (HR=0.87, 95%CI: 0.75, 1.00, P=0.058). In addition, NSCLC patients who were treated with antigen-specific immunotherapy exhibited a significantly higher incidence of adverse events than those treated with other treatments (RR=1.11, 95%CI: 1.00, 1.24; P=0.046).

CONCLUSION

Our study demonstrated the clinical survival benefits of tecemotide and TG4010 in the treatment of NSCLC. However, these evidence might be limited by potential biases. Therefore, further well-conducted, large-scale RCTs are needed to verify our findings.

The efficacy and safety of immunotherapy in patients with advanced NSCLC: a systematic review and meta-analysis

Immunotherapy is a novel treatment for advanced non-small cell lung cancer (NSCLC) patients. Immunotherapy includes two main broad classes of therapeutic vaccines and immune checkpoint inhibitors, as well as cytokines, biological response modifiers and cellular therapy. The present systematic review and meta-analysis aims to evaluate the efficacy and safety of different classes of immunotherapy in patients with advanced NSCLC. Literature search was done on Medline, Embase and Cochrane Library. The primary endpoints were overall survival (OS) and grade ≥3 adverse events. Twenty randomized controlled trials were finally identified in our study. Efficacy analysis indicated an improvement of OS in advanced NSCLC patients after treating by therapeutic vaccines and immune checkpoint inhibitors, but not for other immunomodulators. Safety analysis showed that immunotherapy was well-tolerated. All kinds of grade ≥3 adverse events were similar between experimental group and control group except that neutropenia and thrombocytopenia had a higher incidence in patients received vaccines. In conclusion, immunotherapy is a promising treatment for advanced NSCLC patients. Our findings will be further confirmed and supplemented by several phase II and phase III RCTs which are going to complete in near future.

Efficacy of Tumor Vaccines and Cellular Immunotherapies in Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

PURPOSE

Programmed cell death protein-1- checkpoint blockers have recently been approved as second-line treatment for advanced non-small-cell lung cancer (NSCLC). Unfortunately, only a subgroup of patients responds and shows long-term survival to these therapies. Tumor vaccines and cellular immunotherapies could synergize with checkpoint blockade, but which of these treatments is most efficacious is unknown. In this meta-analysis, we assessed the efficacy of tumor vaccination and cellular immunotherapy in NSCLC.

METHODS

We searched for randomized controlled trials (RCTs) investigating cellular immunotherapy or vaccines in NSCLC. We used random effects models to analyze overall survival (OS) and progression-free survival (PFS), expressed as hazard ratios (HRs), and differences in time (months). The effect of immunotherapy type, disease stage, tumor histology, and concurrent chemotherapy was assessed using subgroup analysis and meta-regression. All procedures were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

We identified 18 RCTs that matched our selection criteria; these included a total of 6,756 patients. Immunotherapy extended NSCLC survival and PFS, expressed as HR (OS: HR, 0.81, 95% CI, 0.70 to 0.94, P = .01; PFS: HR, 0.83, 95% CI, 0.72 to 0.95, P = .006) and month difference (OS: difference, 5.43 months, 95% CI, 3.20 to 7.65, P < .005; PFS: difference, 3.24 months, 95% CI, 1.61 to 4.88, P < .005). Cellular therapies outperformed tumor vaccines (OS as HR: P = .005, month difference: P < .001; PFS as HR: P = .001, month difference: P = .004). There was a benefit of immunotherapy in low-stage compared with high-stage NSCLC and with concurrent administration of chemotherapy only in one of four outcome measures evaluated (PFS in months: P = .01 and PFS as HR: P = .031, respectively). There was no significant effect of tumor histology on survival or PFS.

CONCLUSION

Tumor vaccines and cellular immunotherapies enhanced OS and PFS in NSCLC. Cellular immunotherapy was found to be more effective than tumor vaccination. These findings have implications for future studies investigating combination immunotherapy in NSCLC.