Rate and risk factors of recurrent immune checkpoint inhibitor-related pneumonitis in patients with lung cancer

Real-world incidence and risk factors of pneumonitis in chemoradiation plus immune checkpoint inhibitors compared with chemoradiation alone in lung cancer: a retrospective cohort study

Background

Immune checkpoint inhibitors (ICIs) have shown high efficacy in lung cancer. Adding ICIs to chemoradiation might increase the treatment efficacy, while the application of ICIs or chemoradiation alone can induce treatment-related pneumonitis, so whether combination therapy would increase the risk of pneumonitis needs careful evaluation. This study aimed to retrospectively analyze the incidence of pneumonitis in patients who underwent chemoradiation combined with ICIs compared with chemoradiation alone and explore the risk factors of pneumonitis in combination therapy.

Methods

This was a retrospective cohort study. Patients who received conventional thoracic radiation with a minimum total dose of 50 Gy for lung cancer between January 2020 and December 2021 at West China Hospital were retrospectively reviewed and followed up for at least 6 months after radiation. Patients were divided into two groups according to whether chemoradiation was administered with or without ICIs. Pneumonitis was evaluated by chest computed tomography (CT) at least every 2 months in outpatient department. The clinical characteristics, including sex, age, smoking history, pathological diagnosis, baseline pulmonary disease [including chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD)], treatment strategy, location of primary tumor and radiological dosimetric parameters were recorded. Chi-squared tests or Fisher's exact tests were performed to analyze the difference between the combination group and control group for categorical variables and Mann-Whitney U test for continuous variables. Univariate and multivariate analyses were performed by logistic regression.

Results

A total of 152 patients who received chemoradiation were enrolled. The median age was 59 years. A total of 115 (75.7%) patients were non-small cell lung cancer (NSCLC), 22 (14.5%) were small cell lung cancer (SCLC), and 15 (9.9%) were other pathological types. Among them, 58 received chemoradiation combined with ICIs and 94 received chemoradiation alone. The rate of grade ≥2 pneumonitis was significantly higher in the combination therapy group (39.7% vs. 22.3%, P=0.028) and was associated with the use of ICIs [odds ratio (OR): 2.641, 95% confidence interval (CI): 1.244-5.608, P=0.011] and percent volume of the lung receiving ≥30 Gy (V30) (OR: 1.728, 95% CI: 1.214-2.460, P=0.002). The history of chronic lung disease was the independent risk factor (OR: 6.359, 95% CI: 1.953-20.705, P=0.002) of grade ≥3 pneumonitis. In the combination group, univariate and multivariate analyses revealed that V5, V20, V30, and mean lung dose (MLD) were not associated with pneumonitis, whereas the history of chronic lung disease was an independent risk factor of grade ≥3 pneumonitis (OR: 8.351, 95% CI: 1.469-47.484, P=0.017).

Conclusions

The incidence of pneumonitis of ICIs combined with chemoradiation was higher than chemoradiation alone, but manageable. The combination therapy should be applied with caution especially in patients with history of chronic lung disease.

Drug-induced lung injury in a patient treated with prior atezolizumab and subsequent sotorasib: A case report

We report a case of drug-induced lung injury treated with prior atezolizumab and subsequent sotorasib. The patient was a 62-year-old woman with lung adenocarcinoma harbouring a KRAS G12C mutation that was resistant to chemotherapy, including immune checkpoint inhibitors. Cough and dyspnea appeared on day 80 after sotorasib was administered as second-line therapy, and chest computed tomography revealed ground glass opacities in all lung lobes. Bronchoalveolar lavage fluid showed an increased total cell count with lymphocyte predominance. The patient was considered to have lung injury caused by prior atezolizumab or sotorasib administration. Withdrawal of sotorasib did not improve symptoms and shadows in both lungs. We administered moderate-dose prednisolone and the lung disorder quickly resolved. Prednisolone tapering was completed in 2 months, followed by several months without relapse. Definitive identification of the responsible drug for the drug-induced lung injury proved challenging in the setting of exposure to multiple potential inciting agents. There is a need for high levels of clinical suspicion for timely evaluation and management.

Incidence and outcome of immune checkpoint-induced pneumonitis in oncology patients with history of pulmonary disease

Background

Immune checkpoint-induced pneumonitis (ICIP) is one of the most fatal adverse events caused by immune checkpoint inhibitors (ICI) and accounts for 35% of anti-PD-[L]1-related deaths. Risk factors including thoracic radiation and use of EGFR tyrosine kinase inhibitors have been identified as contributors to ICIP development. However, there has been very limited information on obstructive pulmonary disease as a risk factor.

Objective

The purpose of this study is to evaluate the incidence and management of ICIP in a cohort of patients with pre-existing obstructive pulmonary disease.

Methods

This retrospective, descriptive study, includes data from 139 patients between January 1, 2017 and August 31, 2022. Patients included were adult patients 18 years or older, received at least 2 cycles of an immune checkpoint inhibitor, and had a history of an obstructive pulmonary disorder prior to administration. Patients were excluded if they had literature-established risk factors for pneumonitis.

Results

The incidence of ICIP was 7.19% (10 out of 139 patients). From a management perspective, 90% of patients had immunotherapy held, 40% received oral steroids, and 70% received intravenous steroids at the time of ICIP identification. After receiving treatment for the initial episode of ICIP, 6 patients restarted immunotherapy and 3 (50%) subsequently experienced a recurrent episode. One patient experienced grade 4 ICIP event and subsequently died from respiratory failure attributed to ICIP.

Conclusion

These findings indicate that a pre-existing history of an obstructive pulmonary disorder may be a risk factor for the development of ICIP and subsequent recurrence of ICIP when rechallenged.

Immune checkpoint inhibitor-related chronic pneumonitis: a case report and literature review

Immune checkpoint inhibitor (ICI)-related chronic pneumonitis is rare. Limited information is available on the characteristics of this condition. Herein, we present the case of a 54-year-old man with recurrent severe ICI-related pneumonitis. The patient developed fever and dyspnea during both episodes of pneumonitis. He had been previously diagnosed with gastric signet ring cell carcinoma and was undergoing treatment with an anti-PD-1 combination chemotherapy regimen. We reviewed previous case reports of ICI-related pneumonitis according to the primary cancer, time of onset in relation to ICI therapy and chest imaging findings. ICI-related pneumonitis can progress to chronic pneumonitis. Repeated computed tomography imaging showing lung changes in the same location may help to make the diagnosis.

Six-week oral prednisolone therapy for immune-related pneumonitis: a single-arm phase II study

BACKGROUND

There has been no prospective trial for treatment of immune-related pneumonitis (irP) occurred after immune checkpoint inhibitors (ICIs).

METHODS

In this single-arm phase II study, patients with cancer with grade ≥2 irP received oral prednisolone (1 mg/kg/day), tapered over 6 weeks. The primary endpoint was a pneumonitis control rate at 6 weeks from the start of the study treatment, defined as complete disappearance or partial improvement of irP in high-resolution CT of the chest.

RESULTS

Among 57 patients enrolled, 56 were included in the final analysis. The most frequent cause of irP was single ICI therapy (51.8%), followed by combination with chemotherapy plus ICI (39.3%). Thirty-five (62.5%) patients had grade 2 irP and 21 (37.5%) had grade ≥3. Fifty-one (91.1%) patients completed the study treatment while 5 discontinued the study treatment because of relapse of irP (n=1), death from cancer (n=1), occurrence of immune-related hepatitis (n=1), extension of the treatment duration more than 6 weeks (n=1), and attending physician's decision (n=1). Six weeks after the start of the study treatment, 16 (28.5%) patients demonstrated complete recovery from irP, 35 (62.5%) had a partial improvement in irP, 1 (1.8%) had a relapse of irP, and 4 (7.1%) were not evaluable. The pneumonitis control rate at 6 weeks was 91.1% (95% CI, 80.7% to 96.1%). Twelve weeks after the start of the study treatment, 5 (8.9%), 27 (48.2%), and 15 (26.8%) patients demonstrated complete recovery, partial improvement, and relapse, respectively, and 9 (16.1%) were not evaluable. The pneumonitis control rate at 12 weeks was 57.1% (95% CI, 44.1% to 69.2%). During the observation period, 18 (32.1%) patients experienced a relapse of irP, and of those, 17 received re-treatment with corticosteroids. Grade ≥3 adverse events occurred in 10 (17.9%) patients, in which hyperglycemia was most frequent (n=6). There was no treatment-related death.

CONCLUSIONS

In this first prospective study for irP, prednisolone at 1 mg/kg/day, tapered over 6 weeks, demonstrated a promising clinical benefit and manageable toxicity, suggesting a potential treatment option for irP.

TRIAL REGISTRATION NUMBER

jRCT: 1041190029.

Risk Factors for Refractory Immune Checkpoint Inhibitor-related Pneumonitis in Patients With Lung Cancer

Checkpoint inhibitor-related pneumonitis (CIP) is one of the most important immune checkpoint inhibitors side effects, and it is rare but fatal. Identifying patients at risk of refractory CIP before the start of CIP therapy is important for controlling CIP. We retrospectively analyzed the clinical data of 60 patients with lung cancer who developed CIP. Refractory CIP was defined as CIP with poor response to corticosteroid treatment, including CIP not relieved with corticosteroid administration or CIP recurrence during the corticosteroid tapering period. We analyzed clinical characteristics, peripheral blood biomarkers, treatment, and outcomes in nonrefractory and refractory CIP. Risk factors associated with refractory CIP were assessed. Among 60 patients with CIP, 16 (26.7%) had refractory CIP. The median onset time for patients with nonrefractory and those with refractory CIP was 16.57 (interquartile range [IQR], 6.82-28.14) weeks and 7.43 (IQR, 2.71-19.1) weeks, respectively. The level of lactate dehydrogenase (LDH) was significantly higher in the refractory CIP group at baseline (255 [222, 418] vs. 216 [183, 252], P =0.031) and at CIP onset (321.5 [216.75, 487.5] vs. 219 [198. 241], P =0.019). An LDH level >320 U/L at CIP onset was an independent risk factor of refractory CIP (odds ratio [OR], 8.889; 95% confidence interval [CI]: 1.294-61.058; P =0.026). The incidence of refractory CIP is high among patients with CIP. An increased LDH level at CIP onset is independently associated with refractory CIP. Monitoring LDH levels during immune checkpoint inhibitors treatment is recommended.