P2.16-37 Impact of Brain Metastases on Healthcare Utilisation and Costs in Patients with NSCLC Treated with EGFR-TKIs

NSCLC with brain metastases is difficult to treat and associated with poor survival. The impact of brain metastases compared with other metastases on healthcare utilisation and costs among patients treated with EGFR-TKIs is not well known. Newly-diagnosed adult patients with metastatic NSCLC initiating approved first-/second-generation EGFR-TKI treatment (within 90 days of diagnosis) were identified retrospectively from IBM Watson Health MarketScan® healthcare claims databases from 2013–2017. Patients were divided into mutually-exclusive cohorts based on evidence of brain or non-brain metastasis (BM or NBM). Demographics, clinical characteristics and healthcare expenses were captured at baseline. Healthcare utilisation and cost were analysed during the variable-length follow-up period. Costs were standardised to 2017 US$ and reported as per-patient-per-month (PPPM). Generalised linear models were used to assess the impact of brain metastases, adjusting for baseline demographics, comorbidities, healthcare expenses and length of follow-up. Overall, 222 BM and 280 NBM patients were included. BM patients were, on average, younger than NBM patients (59.9 vs 65.7; p<0.05); both cohorts included mostly female patients and had an average of 14 months follow-up. Among all patients, first EGFR-TKI treatment was 82.3% erlotinib, 16.3% afatinib and 1.4% gefitinib; 10 patients treated with osimertinib were excluded. Seizures (9.0% vs 1.1%), headaches (17.6% vs 10.0%) and altered mental status (11.3% vs 5.7%) were more common in the BM vs NBM cohort (p<0.05). NSCLC-related healthcare utilisation was >2-fold higher in BM patients receiving radiation treatment in the inpatient (15.3% vs 6.8%; p<0.05) and outpatient (87.8% vs 37.5%; p<0.05) settings. PPPM radiation costs were also higher among BM patients in the inpatient ($796 vs $464, p=0.172) and outpatient ($2477 vs $762, p<0.05) settings. All-cause inpatient admissions were more common among the BM vs NBM cohort (67.1% vs 57.1%; p<0.05). While all patients had evidence of outpatient services, the PPPM number of outpatient visits was greater among the BM vs NBM cohort (p<0.05) for both NSCLC-related (5.1 vs 4.2) and all-cause (6.4 vs 5.7) healthcare utilisation. Adjusted NSCLC-related and all-cause PPPM costs were 1.2 times higher among BM patients (+$5674 and +$6393, respectively; p<0.05); age was also a significant predictor in both models (p<0.05). Healthcare utilisation, hospital admission rates and costs, especially those attributable to radiation treatment, were higher among patients with BM compared with NBM. Future research should assess if central nervous system (CNS)-active EGFR-TKIs have the potential to reduce healthcare utilisation and costs associated with brain metastases.