Durvalumab After Chemoradiotherapy in Limited Stage Small Cell Lung Cancer.

Lung cancer is a highly prevalent disease worldwide in women and men. In 2022, lung cancer stood as the most frequently diagnosed cancer with approximately 2.48 million new cases on a global scale, followed by cancers of the female breast (11.6%), colorectum (9.6%), prostate (7.3%), and stomach (4.9%). Lung cancer is the leading cause of cancer death worldwide according to data provided by the International Agency for Research on Cancer. In 2022 they estimated a 1.8 million deaths across the world. Specifically in Spain, from 1980 to 2022, lung cancer led to 745,182 deaths. Histologically, lung cancer (LC) can be classified into two major subtypes: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), accounting for 85% and 15% of LC patients, respectively. Smoking is the major risk factor for SCLC. There are two stages of SCLC: limited-stage SCLC (LS-SCLC) and extensive-stage SCLC (ES-SCLC). Limited-stage (LS) means that the cancer is located on the ipsilateral hemithorax that can be encompassed within a radiation port while extensive-stage (ES) means that the cancer has spread widely throughout the lungs, to non-regional lymph nodes or to other organs. At present, LS is identified in \~30% of patients, and ES is identified in \~70% of patients with SCLC. With a 5-year survival rate of less than 7%, SCLC is still one of the most lethal malignancies and it is also characterized by early metastatic spread. Reflecting this high metastatic capacity, two thirds of patients already have tumor cell dissemination outside the chest at the time of initial diagnosis (ES-SCLC). Therefore, the number of patients with LS-SCLC who can benefit from multimodality therapy with potentially curative intent is limited. SCLC is a highly aggressive form of LC that typically recurs and progresses rapidly despite initial response to chemotherapy and radiotherapy in patients with LS-SCLC. The etoposide/platinum (EP) combination was the standard of care (SoC) for patients with ES-SCLC until 2019, when the addition of immunotherapy to EP chemotherapy was shown to improve survival, with up to 17% of patients remaining alive at 3 years. On the other hand, the SoC for patients with LS-SCLC is concurrent platinum-based chemoradiotherapy (cCRT) ± prophylactic cranial irradiation (PCI) that remained unchanged for decades. Several studies have shown that concurrent chemoradiotherapy (cCRT) is more effective than sequential CRT (sCRT) in LS-SCLC. Nonetheless, subject to the lymph node regions involvement and treatment-related toxicities, some patients do not undergo concurrent CRT and instead receive sequential CRT. In a non-interventional, retrospective cohort study of limited-stage SCLC patients conducted in France, Italy and the UK, sequential chemoradiotherapy accounts for 37.6% of all treatment patterns while concurrent chemoradiotherapy accounts for 35.1% of the whole therapies used as first line. ADRIATIC (NCT03703297) is a phase 3, randomized, double-blind, placebo-controlled, multicenter, global study evaluating durvalumab ± tremelimumab as consolidation therapy for patients with LS-SCLC who have not progressed after cCRT. Positive high-level results of the ADRIATIC clinical trial showed durvalumab demonstrated a statistically significant and clinically meaningful improvement in the dual primary endpoints of overall survival (OS) and progression-free survival (PFS) in patients with LS-SCLC who had not progressed following cCRT compared to placebo. Durvalumab was well tolerated, and AEs were consistent with the known safety profile. These data support the consolidation of durvalumab as a new SoC for patients with LS-SCLC who have not progressed after cCRT. There is limited information on the effectiveness and safety of durvalumab in a broader patient population with LS-SCLC, including those who received sequential CRT. Therefore, there remains an unmet need for additional data to help support and inform the healthcare decisions on the use of durvalumab as consolidation treatment for patients with LS-SCLC in real-world clinical practice. In addition, ADRIATIC study did not allow to include patients with ECOG PS 2 assessed after CRT. The present phase IIIb study will assess the safety and effectiveness of durvalumab in real world like LS-SCLC population. Furthermore, this trial will focus on patient characteristics, treatment exposure, administration, quality of life (QoL), effectiveness and safety providing insights into durvalumab use.