Abstract 1611P
Background
Historically, adverse event (AE)-related hospitalizations were reported in >50% of pts on chemotherapy, while limited data exist for pts on ICIs. We examined real-world HCRU and costs for pts with urothelial carcinoma (UC), renal cell carcinoma (RCC), non-small cell lung cancer (NSCLC), or Merkel cell carcinoma (MCC) treated with PD-L1/PD-1 ICIs who experienced irAEs.
Methods
This retrospective cohort study used Optum's claims database to identify US commercial and Medicare Advantage health plan members with UC, RCC, MCC, or NSCLC treated with ICIs between 01 Sep 14 and 30 Apr 19. Twenty-one irAEs were chosen a priori based on ASCO guidelines. Pts were followed up for newly occurring irAEs, based on ICD codes from claims, from ICI initiation to earliest date of following: 6 months after initial line of ICI therapy ended, start of new treatment, death, disenrollment, or 30 Apr 19. irAE-related HCRU and costs were calculated in the same time period. HCRU and costs were considered irAE related if an ICD code for an irAE was present in field 1 or 2 on the claim. Descriptive analyses used per-patient-per-month (PPPM) measures and the Kaplan-Meier method.
Results
Among pts treated with ICI monotherapy with irAEs (N=955; 71 y, 54% male, 69% with treatment before ICI), the top HCRU for irAEs was ambulatory visits (0.23 PPPM), followed by inpatient stays (0.09 PPPM; Table). Mean irAE-related medical costs were $2,359 PPPM, driven by the cost of inpatient stays. 34% of all pts who experienced an irAE had an irAE-related inpatient stay within 12 mo after ICI initiation.
Conclusions
Inpatient stays were the driver for irAE-related costs; approximately one-third of pts with an irAE ultimately required an inpatient stay within a year of initiating ICIs. These study findings help elucidate the economic burden associated with the management of ICI irAEs. Table: 1611P
irAE-related HCRU and costs among ICI pts with an irAE
| All Patients N=955 | UC n=90 | RCC n=127 | NSCLC n=722 | MCC n=16 | |
| HCRU, mean ± SD, visits PPPM | |||||
| Ambulatory | 0.23 ± 0.57 | 0.30 ± 1.14 | 0.21 ± 0.28 | 0.23 ± 0.50 | 0.28 ± 0.27 |
| Emergency department | 0.03 ± 0.14 | 0.06 ± 0.22 | 0.03 ± 0.11 | 0.03 ± 0.13 | 0.03 ± 0.06 |
| Inpatient stay | 0.09 ± 0.23 | 0.16 ± 0.43 | 0.08 ± 0.16 | 0.09 ± 0.20 | 0.02 ± 0.05 |
| Medical costs PPPM, mean ± SD, US $ | 2,359 ± 7,496 | 4,195 ± 12,699 | 2,066 ± 4,339 | 2,221 ± 7,113 | 563 ± 1,219 |
| Ambulatory | 201 ± 1,150 | 116 ± 389 | 422 ± 2,118 | 176 ± 968 | 42 ± 69 |
| Emergency department | 11 ± 70 | 22 ± 113 | 7 ± 25 | 11 ± 69 | 11 ± 33 |
| Inpatient stay | 2,120 ± 7,190 | 3,831 ± 11,009 | 1,636 ± 3,955 | 2,029 ± 7,085 | 468 ± 1,101 |
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
EMD Serono, Inc.; a business of Merck KGaA, Darmstadt, Germany; Pfizer, Inc.
Funding
EMD Serono, Inc.; a business of Merck KGaA, Darmstadt, Germany, Germany; Pfizer, Inc.
Disclosure
S. George: Advisory/Consultancy, Research grant/Funding (institution): Bayer; BMS; Research grant/Funding (institution): Agensys; Advisory/Consultancy: Exelixis; Genentech; Sanofi/ Genzyme; Advisory/Consultancy, Research grant/Funding (institution): Corvus; Advisory/Consultancy, Research grant/Funding (institution): Pfizer; Merck; Eisai; EMD Serono. Y. Zheng: Full/Part-time employment: EMD Serono Research & Development Institute, Inc. E.J. Bell: Research grant/Funding (self): Novartis; Sandoz; Incyte; EMD Serono Research & Development Institute, Inc.; Celgene; AstraZeneca; Full/Part-time employment: Optum. N.M. Engel-Nitz: Research grant/Funding (institution): EMD Serono Research & Development Institute, Inc.; Exact Sciences; Alexion; AstraZeneca; GlaxoSmithKline; Eli Lilly; Genentech; UnitedHealth Care; Shareholder/Stockholder/Stock options, Full/Part-time employment: UnitedHealth Group. J.C. White: Research grant/Funding (institution): EMD Serono Research & Development Institute, Inc.; Research grant/Funding (institution): Optum; Full/Part-time employment: Optum. L.S. Lal: Full/Part-time employment: Optum. R. Kim: Full/Part-time employment: Pfizer Inc. S. Krulewicz: Full/Part-time employment: Pfizer Inc. J. Smith: Leadership role, Research grant/Funding (self), Travel/Accommodation/Expenses, Shareholder/Stockholder/Stock options, Full/Part-time employment: EMD Serono Research & Development Institute, Inc. F.X. Liu: Full/Part-time employment: EMD Serono Research & Development Institute, Inc.