Progression Patterns, Treatment, and Prognosis Beyond Resistance of Responders to Immunotherapy in Advanced Non-Small Cell Lung Cancer

Introduction

Immune checkpoint inhibitors (ICIs) have changed the management of non-small cell lung cancer (NSCLC). However, resistance is inevitable. The disease progression patterns, sequential treatment, and prognosis beyond ICI resistance are not completely understood.

Methods

We retrospectively analyzed stage IV NSCLC patients who underwent ICI treatment at Zhejiang Cancer Hospital between January 2016 and January 2020 and who suffered disease progression after at least stable disease on immunotherapy for more than 3 months (at least two cycles). Oligoprogression and systematic progression were defined as previous reports. The main outcome measures were progression-free survival (PFS), second PFS (PFS2), and overall survival (OS). Survival curves were plotted using the Kaplan-Meier method. The Cox proportional hazards model was used for multivariate analysis.

Results

Totally 1,014 NSCLC patients were administered immunotherapy. Of them, 208 NSCLC patients were included in this retrospective study. The estimated PFS, PFS2 and OS were 6.3 months (95% CI 5.6–7.0 months), 10.7 months (95% CI 10.1–12.7 months), and 21.4 months (95% CI 20.6–26.4 months), respectively. After resistance, 55.3% (N = 115) patients developed oligoprogression, and 44.7% (N = 93) systemic progression. For patients with systemic progression, chemotherapy (N = 35, 37.6%), best supportive care (N = 30, 32.3%), and antiangiogenic therapy alone (N = 11, 11.8%) were the major strategies. A combination of local radiotherapy (N = 38, 33.0%) with continued ICIs was the most common treatment used in oligoprogression group, followed by continued immunotherapy with antiangiogenic therapy (N = 19, 16.5%) and local radiotherapy only (N = 17, 14.9%). For patients with oligoprogression, continued immunotherapy plus local radiotherapy can lead to a significantly longer PFS2 (12.9 vs. 10.0 months; p = 0.006) and OS (26.3 vs. 18.5 months, p = 0.001). The PFS2 and OS of patients with oligoprogression were superior to those of patients with systemic progression (PFS2: 13.1 vs. 10.0 months, p = 0.001; OS: 25.8 vs. 19.1 months, p = 0.003).

Conclusions

The major progression pattern after acquired resistance from immunotherapy is oligoprogression. Local radiotherapy with continued immunotherapy beyond oligoprogression in responders was feasible and led to prolonged PFS2 and OS in advanced NSCLC patients.

Immune Response Evaluation and Treatment with Immune Checkpoint Inhibitors Beyond Clinical Progression: Response Assessments for Cancer Immunotherapy

PURPOSE OF REVIEW

This review provides a comprehensive assessment of recent literature reports describing atypical response patterns observed with immune checkpoint inhibitors (ICIs), modifications to response evaluation criteria for ICIs, and treatment beyond progression in clinical trials.

RECENT FINDINGS

Certain response patterns such as durable response, pseudoprogression, hyperprogression, and dissociated responses can be seen with ICI treatment. These patterns carry differing prognoses and are associated with varied factors. There are multiple modifications of standard Response Evaluation Criteria in Solid Tumors (RECIST) that have been proposed to better characterize immunotherapy response; however, standard RECIST1.1 remains most commonly used in clinical trials. Treatment beyond progression varies in frequency and benefit depending on assessment criteria and cancer type. Future research incorporating modified imaging criteria and biomarker assessments may serve to clarify who will benefit most from treatment beyond progression.

Atezolizumab: A Review in Previously Treated Advanced Non-Small Cell Lung Cancer

Atezolizumab (TECENTRIQ™), an immune checkpoint inhibitor, is an immunoglobulin G1 monoclonal antibody that binds to programmed death ligand 1 (PD-L1) and blocks its interactions with programmed death 1 and B7.1 receptors. Atezolizumab is approved as monotherapy in several countries worldwide for the treatment of patients with advanced non-small cell lung cancer (NSCLC) who have previously received chemotherapy. Approval was based on its clinical benefit in this setting in the phase II POPLAR and phase III OAK trials. In these studies, atezolizumab significantly prolonged overall survival (OS) relative to docetaxel, regardless of PD-L1 status. Increasing PD-L1 expression was associated with OS improvements. Atezolizumab also demonstrated efficacy in the phase II FIR and BIRCH trials, as assessed by objective response rates (ORRs) in patients with tumours expressing PD-L1. Higher ORRs were seen in patients with high PD-L1 expression. Atezolizumab had an acceptable, manageable tolerability profile, with a low incidence of immune-related adverse events. Therefore, atezolizumab is a valuable treatment option for patients with advanced NSCLC that has progressed during or after chemotherapy.