Primary completion results for a Phase 3 study evaluating atezolizumab in combination with chemoradiation for limited stage small cell lung cancer (LS-SCLC) were posted on ClinicalTrials.gov on 2024-04-21. The trial found no significant improvement in overall survival (OS) or progression-free survival (PFS) with the addition of atezolizumab, with a median OS of 31.1 months for the atezolizumab arm compared to 36.1 months for the control arm (HR 1.05, 95% CI: 0.82-1.34, p=0.5819).
Background
The study investigated atezolizumab, an immunotherapy drug, in combination with standard chemoradiation therapy (CRT) for patients with limited stage small cell lung cancer (LS-SCLC). Atezolizumab is a monoclonal antibody designed to help the body's immune system target tumor cells.
Trial design
The Phase 3 study (NCT03811002) enrolled 544 participants with limited stage small cell lung cancer (LS-SCLC), including Stage I, II, and III. The trial aimed to evaluate the addition of atezolizumab to usual chemoradiation therapy (CRT) compared to CRT alone. Interventions included atezolizumab, carboplatin, cisplatin, and etoposide, alongside radiation therapy.
Key results
Key results from the trial include:
- Overall Survival (OS): The median OS was 36.1 months for the chemoradiation (Arm I) group and 31.1 months for the chemoradiation plus atezolizumab (Arm II) group. The hazard ratio (HR) for OS was 1.05 (95% Confidence Interval: 0.82 to 1.34), with a p-value of 0.5819.
- Progression Free Survival (PFS): The median PFS was 11.4 months for Arm I and 12.1 months for Arm II. The hazard ratio (HR) for PFS was 0.98 (95% Confidence Interval: 0.8 to 1.21).
- Adverse Events: For the outcome 'Number of Participants by Highest Grade Adverse Event Reported', Arm I reported counts of 4, 3, 8, and 56 participants, while Arm II reported counts of 0, 0, 9, and 63 participants.
What this means
The results indicate that adding atezolizumab to standard chemoradiation therapy did not significantly improve overall survival or progression-free survival for patients with limited stage small cell lung cancer. The median overall survival was numerically shorter in the atezolizumab arm compared to the control arm. Similarly, while progression-free survival was numerically slightly longer in the atezolizumab arm, the hazard ratio suggests no statistically significant benefit. The adverse event reporting indicates similar numbers of participants experiencing highest grade adverse events across both treatment arms, though specific details on the nature or severity of these events are not provided.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The primary completion results for the study NCT03811002, titled "Testing the Addition of a New Immunotherapy Drug, Atezolizumab (MPDL3280A), to the Usual Chemoradiation (CRT) Therapy Treatment for Limited Stage Small Cell Lung Cancer (LS-SCLC)", were posted on 2024-04-21 on clinicaltrials.gov.