P1.16-06 Early Changes in Pulmonary Function Are Associated with Development of Pneumonitis in NSCLC Patients Receiving Immune Checkpoint Blockade

Chinese expert consensus on the multidisciplinary management of pneumonitis associated with immune checkpoint inhibitor

Immune checkpoint inhibitors (ICIs) have successfully treated a number of different types of cancer, which is of great significance for cancer treatment. With the widespread use of ICIs in clinical practice, the increasing checkpoint inhibitor pneumonia (CIP) will be a challenge to clinicians. To guide the diagnosis and treatment of CIP, we conducted in-depth discussions based on the latest evidence, forming a consensus among Chinese experts on the multidisciplinary management of CIP.

Pembrolizumab Induced Acute Persistent Airway Disease in a Patient with Recurrent Respiratory Papillomatosis (RRP)

OBJECTIVE

To present an uncommon but serious, recently identified complication of checkpoint inhibitor therapy in a patient treated with pembrolizumab infusion for disseminated recurrent respiratory papillomatosis (RRP).

METHODS

Case report.

RESULTS

A 43-year-old woman with underlying asthma developed acute hypoxic respiratory failure within 24 hours of her third infusion of pembrolizumab for treatment of intractable, disseminated recurrent respiratory papillomatosis. Pulmonary function testing revealed a severe intra-thoracic obstructive ventilatory defect. Discontinuation of pembrolizumab, ventilatory support, and treatment with systemic and inhaled corticosteroids resulted in resolution of respiratory failure; however, her underlying asthma remains poorly controlled.

CONCLUSION

To our knowledge, this case is the first report of pembrolizumab-induced obstructive respiratory failure in a patient being treated for RRP.

Prospective Observational Study Revealing Early Pulmonary Function Changes Associated With Brigatinib Initiation

INTRODUCTION

Symptomatic early onset pulmonary events (EOPEs) were observed in 3% to 6% of patients within 1 week of starting brigatinib at 90 mg daily for 7 days followed by 180 mg daily. We conducted a prospective observational cohort study to measure pulmonary function changes on initiating brigatinib.

METHODS

Patients initiating brigatinib were eligible. Pulmonary function test (PFT) with diffusing capacity for carbon monoxide (DLCO), Borg dyspnea scale, six-minute walk test, and blood draw for cytometry by time-of-flight were performed at baseline, day 2, and day 8 plus or minus day 15 of brigatinib. The primary end point was the incidence of PFT-defined EOPEs, prespecified as greater than or equal to 20% DLCO reduction from baseline. An interim analysis was performed owing to a higher than expected incidence of DLCO reduction.

RESULTS

A total of 90% (nine of 10) experienced DLCO reduction with the nadir occurring on day 2 or day 8. Median DLCO nadir was -13.33% from baseline (range: -34.44 to -5.00). Three participants met the PFT-defined EOPE criteria. All patients, including these three, were asymptomatic, none required brigatinib interruption or dose reduction, and all patients escalated to 180 mg without further issues. Despite continued dosing, by day 15, all assessed patients experienced DLCO recovery. Dyspnea and six-minute walk test results did not correlate with DLCO changes. Patients with a PFT-defined EOPE had significantly higher levels of activated neutrophils at baseline and day 8.

CONCLUSIONS

DLCO reduction occurred in 90% during the first 8 days of brigatinib dosing without any related symptoms. DLCO improved in all six patients assessed at day 15 despite continued dosing and dose escalation. Pretreatment levels of neutrophil activation should be explored as a biomarker for developing EOPEs.

Checkpoint Inhibitor Pneumonitis: Mechanisms, Characteristics, Management Strategies, and Beyond

PURPOSE OF REVIEW

Checkpoint inhibitor pneumonitis (CIP) is a toxicity of immune checkpoint blockade (ICB) that can be highly morbid and at times fatal. Here, we review the proposed biologic mechanisms of CIP, epidemiology and risk factors for CIP development, diagnostic work-up and management strategies for CIP, and future directions of CIP research.

RECENT FINDINGS

CIP incidence appears to be greater in real-world populations and may continue to rise as FDA approvals for ICB continue to expand to multiple malignancies. Multiple retrospective studies and case series have identified potential risk factors for CIP. Several society guidelines have helped to unify the classification of CIP severity and standardize treatment approaches but significant gaps remain, including formal validated diagnostic criteria for CIP. While significant strides have been made in enhancing the knowledge and management of CIP, ongoing research is needed to continue to advance our understanding of the biologic underpinnings of CIP, as well as optimize diagnostic and management strategies for this potentially devastating toxicity.