Long-Term Survival and Stable Disease in a Patient with Extensive-Stage Small-Cell Lung Cancer after Treatment with Carboplatin, Etoposide and Atezolizumab

Abstract

Survival beyond 2 years is rare in patients with extensive-stage small-cell lung cancer (ES-SCLC) treated with chemotherapy alone. We describe a patient with ES-SCLC who was treated with carboplatin, etoposide and the programmed death-ligand 1 inhibitor atezolizumab in the IMpower133 study (ClinicalTrials.gov registration: NCT02763579) and who achieved exceptionally long-term survival. Treatment-naïve patients with ES-SCLC (n = 403) were included in the IMpower133 study, and the identified patient had been randomised to the investigational treatment arm, where patients received induction therapy with carboplatin and etoposide plus atezolizumab for four 21-day cycles, followed by ongoing maintenance therapy with atezolizumab. The patient had achieved a partial response after induction therapy, and then received seven cycles of atezolizumab maintenance therapy until immune-related toxicities necessitated discontinuation. The patient was alive with an ongoing response and excellent performance status more than 6 years after starting treatment and 5 years after discontinuing atezolizumab maintenance. In conclusion, this patient with ES-SCLC from the IMpower133 study is a rare example of ongoing survival more than 6 years beyond diagnosis and the start of treatment with first-line atezolizumab. This demonstrates the potential durability of response with immunotherapy.

Keywords: Atezolizumab; Carboplatin; Etoposide; Long-term survival; Small-cell lung cancer.

Fig. 1

Computed tomography images showing A mediastinal and right hilar adenopathy with multiple conglomerate masses involving the bronchus of the upper right lobe and surrounding the superior vena cava (27 October 2016), B partial response after induction therapy with four 21-day cycles of carboplatin + etoposide + atezolizumab (26 January 2017) and C continued partial response more than 5 years after stopping maintenance treatment (26 January 2023)

Fig. 2

Immunohistochemical stains for A CD56 and B Ki-67

Fig. 3

Bone gammagraphy image of the upper leg showing metastasis in the femur

Fig. 4

Staining of tissue collected during a kidney biopsy performed in July 2017 (5 days after resuming atezolizumab maintenance treatment) showing immunotherapy-induced nephropathy