Impact of the treatment crossover design on comparative efficacy in EMPOWER-Lung 1: Cemiplimab monotherapy as first-line treatment of advanced non-small cell lung cancer

Objectives

In randomized-controlled crossover design trials, overall survival (OS) treatment effect estimates are often confounded by the control group benefiting from treatment received post-progression. We estimated the adjusted OS treatment effect in EMPOWER-Lung 1 (NCT03088540) by accounting for the potential impact of crossover to cemiplimab among controls and continued cemiplimab treatment post-progression.

Methods

Patients were randomly assigned 1:1 to cemiplimab 350 mg every 3 weeks (Q3W) or platinum-doublet chemotherapy. Patients with disease progression while on or after chemotherapy could receive cemiplimab 350 mg Q3W for ≤108 weeks. Those who experienced progression on cemiplimab could continue cemiplimab at 350 mg Q3W for ≤108 additional weeks with four chemotherapy cycles added. Three adjustment methods accounted for crossover and/or continued treatment: simplified two-stage correction (with or without recensoring), inverse probability of censoring weighting (IPCW), and rank-preserving structural failure time model (RPSFT; with or without recensoring).

Results

In the programmed cell death-ligand 1 ≥50% population (N=563; median 10.8-month follow-up), 38.2% (n=107/280) crossed over from chemotherapy to cemiplimab (71.3%, n=107/150, among those with confirmed progression) and 16.3% (n=46/283) received cemiplimab treatment after progression with the addition of histology-specific chemotherapy (38.7%, n=46/119, among those with confirmed progression). The unadjusted OS hazard ratio (HR) with cemiplimab versus chemotherapy was 0.566 (95% confidence interval [CI]: 0.418, 0.767). Simplified two-stage correction—the most suitable method based on published guidelines and trial characteristics—produced an OS HR of 0.490 (95% CI: 0.365, 0.654) without recensoring and 0.493 (95% CI: 0.361, 0.674) with recensoring. The IPCW and RPSFT methods produced estimates generally consistent with simplified two-stage correction.

Conclusions

After adjusting for treatment crossover and continued cemiplimab treatment after progression with the addition of histology-specific chemotherapy observed in EMPOWER-Lung 1, cemiplimab continued to demonstrate a clinically important and statistically significant OS benefit versus chemotherapy, consistent with the primary analysis.

Outcomes Associated With Medications for Opioid Use Disorder Among Persons Hospitalized for Infective Endocarditis

BACKGROUND

Endocarditis, once predominately found in older adults, is increasingly common among younger persons who inject drugs. Untreated opioid use disorder (OUD) complicates endocarditis management. We aimed to determine if rates of overdose and rehospitalization differ between persons with OUD with endocarditis who are initiated on medications for OUD (MOUDs) within 30 days of hospital discharge and those who are not.

METHODS

We performed a retrospective cohort study using a large commercial health insurance claims database of persons ≥18 years between July 1, 2010, and June 30, 2016. Primary outcomes included opioid-related overdoses and 1-year all-cause rehospitalization. We calculated incidence rates for the primary outcomes and developed Cox hazards models to predict time from discharge to each primary outcome as a function of receipt of MOUDs.

RESULTS

The cohort included 768 individuals (mean age 39 years, 51% male). Only 5.7% of people received MOUDs in the 30 days following hospitalization. The opioid-related overdose rate among those who did receive MOUDs in the 30 days following hospitalization was lower than among those who did not (5.8 per 100 person-years [95% confidence interval [CI], 5.1-6.4] vs 7.3 per 100-person years [95% CI, 7.1-7.5], respectively). The rate of 1-year rehospitalization among those who received MOUDs was also lower than those who did not (162.0 per 100 person-years [95% CI, 157.4-166.6] vs 255.4 per 100 person-years [95% CI, 254.0-256.8], respectively). In the Cox hazards models, the receipt of MOUDs was not associated with either of the outcomes.

CONCLUSIONS

MOUD receipt following endocarditis may improve important health-related outcomes in commercially insured persons with OUD.