Immune cells attacking lung cancer cells with Atezolizumab molecule.

Atezolizumab: Revolutionizing the Fight Against Non-Small Cell Lung Cancer

Samir D’Costa in Health & Wellness December 2025 • 4 min read.

"Unlocking New Possibilities in Lung Cancer Treatment"

Lung cancer remains a formidable challenge, but innovative therapies are continually emerging to improve patient outcomes. Among these, Atezolizumab (Tecentriq®) stands out as a significant advancement. This humanized IgG1 antibody targets PD-L1, a protein that can help cancer cells evade the immune system. By blocking the interaction between PD-L1 and its receptors, Atezolizumab unleashes the body's natural defenses to fight tumor cells.

Atezolizumab is engineered to avoid antibody-dependent cell-mediated cytotoxicity, ensuring that activated T cells, crucial for fighting cancer, remain unharmed. This precise action allows the immune system to recognize and attack cancer cells more effectively. The result is a more robust and targeted immune response against the tumor.

The potential of Atezolizumab has been highlighted in several clinical trials, demonstrating its ability to improve objective response rates (ORR) in patients with non-small cell lung cancer (NSCLC). Compared to historical controls, patients treated with Atezolizumab have shown promising results, marking a significant step forward in lung cancer therapy.

How Does Atezolizumab Improve Outcomes for NSCLC Patients?

Immune cells attacking lung cancer cells with Atezolizumab molecule.

The open-label phase II BIRCH trial, involving 659 patients with PD-L1-expressing tumors, provided compelling evidence of Atezolizumab's efficacy. In this study, the objective response rate (ORR) was evaluated in patients treated with Atezolizumab (1200 mg IV every three weeks). The results were encouraging, with ORRs of 22% in treatment-naïve patients, 19% in the second-line setting, and 18% in those receiving Atezolizumab as third-line therapy.

Notably, higher ORRs (26–31%) were observed in subgroups with greater PD-L1 expression (TC3 or IC3) for both first-line and subsequent treatments. However, it’s worth mentioning that in the first-line setting, the results were comparable to traditional chemotherapy. Importantly, the EGFR or KRAS mutation status did not affect treatment responses, highlighting Atezolizumab's broad applicability.

BIRCH Trial Results: An open-label phase II trial showed promising ORRs with Atezolizumab in treatment-naïve and previously treated patients.
PD-L1 Expression: Higher ORRs were observed in subgroups with greater PD-L1 expression (TC3 or IC3).
Mutation Status: EGFR and KRAS mutation status did not impact treatment responses, suggesting broad applicability.

Follow-up survival analysis at 20 months revealed that the median overall survival (OS) was highest in first-line treated patients at 23.5 months, compared to 15.5 months in the second-line cohort and 13.2 months in the third-line cohort. While PD-L1 status did not seem to impact OS, treatment with Atezolizumab significantly improved OS relative to platinum-based chemotherapy, especially in patients with high PD-L1 expression.

Future Directions and Concluding Thoughts

Atezolizumab has undeniably transformed the treatment landscape for advanced non-small cell lung cancer. As research continues, future challenges include identifying the most effective treatment sequences, standardizing PD-L1 IHC assays, understanding resistance mechanisms, and discovering additional biomarkers to optimize the benefits of immunotherapy for more patients. With ongoing efforts, there is hope for improved outcomes and a better quality of life for those affected by this challenging disease.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.21037/jtd.2017.09.73, Alternate LINK

Title: Atezolizumab In Advanced Non-Small Cell Lung Cancer

Subject: Pulmonary and Respiratory Medicine

Journal: Journal of Thoracic Disease

Publisher: AME Publishing Company

Authors: Marius Ilie, Paul Hofman

Published: 2017-10-01

Everything You Need To Know

How does Atezolizumab work to fight non-small cell lung cancer (NSCLC)?

Atezolizumab, also known as Tecentriq®, is a humanized IgG1 antibody that targets PD-L1. PD-L1 is a protein that cancer cells use to avoid the immune system. By blocking the interaction between PD-L1 and its receptors, Atezolizumab unleashes the body's natural defenses, allowing the immune system to recognize and attack tumor cells. It is specifically engineered to avoid antibody-dependent cell-mediated cytotoxicity, ensuring that activated T cells, which are crucial for fighting cancer, remain unharmed, leading to a more robust and targeted immune response against the tumor.

What were the key findings of the BIRCH trial regarding Atezolizumab's effectiveness in treating NSCLC?

The open-label phase II BIRCH trial, which involved 659 patients with PD-L1-expressing tumors, demonstrated encouraging objective response rates (ORRs) with Atezolizumab. The ORRs were 22% in treatment-naïve patients, 19% in the second-line setting, and 18% in patients receiving Atezolizumab as a third-line therapy. Notably, higher ORRs (26–31%) were observed in subgroups with greater PD-L1 expression (TC3 or IC3) for both first-line and subsequent treatments. However, in the first-line setting, the results were comparable to traditional chemotherapy. The EGFR or KRAS mutation status did not affect treatment responses, highlighting Atezolizumab's broad applicability.

How does PD-L1 expression level impact the effectiveness of Atezolizumab in NSCLC treatment?

The level of PD-L1 expression significantly influences the effectiveness of Atezolizumab. The BIRCH trial demonstrated that higher objective response rates (ORRs) were observed in subgroups with greater PD-L1 expression (TC3 or IC3), with ORRs ranging from 26% to 31% in both first-line and subsequent treatments. While PD-L1 status did not seem to impact overall survival (OS), treatment with Atezolizumab significantly improved OS relative to platinum-based chemotherapy, especially in patients with high PD-L1 expression.

In what ways has Atezolizumab changed the approach to treating advanced non-small cell lung cancer (NSCLC), and what challenges remain?

Atezolizumab has undeniably transformed the treatment landscape for advanced NSCLC by offering a targeted immunotherapy approach that improves objective response rates (ORR) and overall survival (OS) in certain patient subgroups. However, several challenges remain, including identifying the most effective treatment sequences, standardizing PD-L1 IHC assays, understanding resistance mechanisms, and discovering additional biomarkers to optimize the benefits of immunotherapy for more patients. Future research aims to address these challenges to further improve outcomes and quality of life for those affected by this challenging disease.

Does the presence of EGFR or KRAS mutations affect how well Atezolizumab works in treating non-small cell lung cancer?

According to the BIRCH trial, the EGFR or KRAS mutation status did not significantly impact treatment responses to Atezolizumab. This suggests that Atezolizumab has broad applicability across different NSCLC patient subgroups, regardless of their EGFR or KRAS mutation status. This is an important finding as it broadens the potential patient population that could benefit from Atezolizumab therapy.