Cost of cytokine release syndrome in patients treated with tarlatamab for extensive-stage small cell lung cancer based on first-line treatment.

Abstract

e13554 Background: Tarlatamab is a second-line treatment for extensive-stage small cell lung cancer (SCLC) and has changed care for this condition. One factor affecting first-line treatment decisions is overall treatment cost. In this study, we examined the real-world frequency of cytokine release syndrome (CRS) in patients who received tarlatamab and compared the first-line treatments and estimated CRS costs for each. Methods: This was a retrospective cohort analysis using TriNetX Research Network data from the Global Collaborative Network. We included lung cancer patients treated with tarlatamab after atezolizumab (with or without lurbinectedin) or durvalumab. We compared rates of CRS, ICANS, and use of tocilizumab, dexamethasone, or methylprednisolone within 24 hours of tarlatamab using age-adjusted Cox regression analysis. The difference between hospitalization with and without CRS, and the cost of CRS treatment, was acquired from previously reported data from the National Inpatient Sample and Vizient. Expected per-patient costs were estimated by applying age-adjusted hazard ratios for tocilizumab and corticosteroid exposure to baseline CRS rates. Cost uncertainty was derived using 95% confidence intervals of the hazard ratios. Results: The rates of CRS in this study were similar in all the patients, irrespective of their initial treatment. The rates of ICANS were not significantly different in any group. The estimated cost of CRS was highest in the group treated with atezolizumab and lurbinectedin. Higher rates of CRS were noted in the patients in this cohort. The estimated cost of CRS was slightly lower in the durvalumab cohort than in the group treated with atezolizumab. There were slightly lower CRS rates and use of tocilizumab in the durvalumab group. However, the predicted difference in CRS cost between the patients treated with atezolizumab or durvalumab was not significant. Conclusions: The overall cost of treatment in the extensive-stage SCLC remains important to consider. However, the decisions made in the first-line setting do not appear to affect the cost of CRS treatment following tarlatamab. Atezolizumab Atezolizumab + Lurbinectidin Durvalumab n (%) HR (95% CI) n (%) HR (95% CI) n (%) CRS 51/139 (36.7) 1.031 (0.657, 1.619) 37/91 (40.7) 1.018 (0.649, 1.598) 35/98 (35.7) ICANS 24/139 (17.3) 0.817 (0.413, 1.614) 15/91 (16.5) 1.037 (0.537, 2.002) 16/98 (16.3) Tocilizumab 18/51 (35.3) 1.165 (0.576, 2.355) 11/37 (29.7) 0.854 (0.399, 1.825) 12/35 (34.3) Steroids 39/51 (76.5) 1.116 (0.685, 1.819) 28/37 (75.7) 1.39 (0.862, 2.241) 32/35 (91.4) Tocilizumab & Steroids 18 -- 10 -- 11 CRS cost* $87,740 -- $96,342 -- $86,161 Predicted Difference* -- $3,849 (-$30,572, $59,826) -- $1,429 (-$31,943, $55,675) -- *Per patient treated with tarlatamab.