# Therapy for Stage IV Non–Small Cell Lung Cancer Without Driver Alterations: 2026.3.1 Study Guide This study guide provides a comprehensive overview of the ASCO Living Guideline (Version 2026.3.1) regarding systemic therapy for patients with stage IV non–small cell lung cancer (NSCLC) who do not possess driver alterations. It synthesizes current clinical recommendations, evidence from recent clinical trials, and foundational concepts for managing this patient population. --- ## Key Concepts and Clinical Framework ### 1. Living Guideline Methodology Living guidelines are designed for medical fields with rapidly evolving evidence. They are updated on a regular schedule by a standing expert panel that systematically reviews literature. * **Major Updates (e.g., 2026.2.0):** Represent significant revisions or full updates involving comprehensive literature reviews. * **Rapid Updates (e.g., 2026.2.1):** Serve as timely notifications of revised recommendations or supporting evidence between full cycles. ### 2. Patient Population and Biomarker Testing The guidelines apply specifically to patients with stage IV NSCLC who lack "driver alterations"—specifically genomic alterations in *EGFR, ALK, BRAF,* or *ROS1*. * **Universal Testing:** Biomarker testing should be accessible for all patients using broad multigene panels (tissue or blood-based) and IHC assays for PD-L1, HER2, and MET. * **Testing Preference:** Comprehensive RNA-based next-generation sequencing (NGS) is preferred. While liquid biopsy is useful, clinicians must account for its false-negative rate. * **PD-L1 IHC:** This assay should not be used in isolation to guide treatment decisions; it must be part of a broader diagnostic context. ### 3. General Management Principles * **Palliative Care:** Patients should be referred to interdisciplinary palliative care teams early in the course of the disease, alongside active cancer treatment. * **Standard of Care:** For patients not eligible for immune checkpoint inhibitors (ICIs), platinum-doublet combination therapy remains the standard for those with preserved performance status (PS). --- ## First-Line Treatment Recommendations Treatment selection is primarily guided by histology (Nonsquamous vs. Squamous) and PD-L1 Tumor Proportion Score (TPS). ### Nonsquamous Cell Carcinoma | PD-L1 Expression | Strong Recommendations (S) | Conditional Recommendations (C) | | :--- | :--- | :--- | | **TPS ≥ 50%** | Pembrolizumab, Cemiplimab, or Atezolizumab (monotherapy) | Combination regimens including Retifanlimab + platinum-based chemo; Nivolumab + Ipilimumab ± chemo; Durvalumab + Tremelimumab + chemo. | | **TPS 1%–49%** | Pembrolizumab + Carboplatin + Pemetrexed; Cemiplimab + Carboplatin + Pemetrexed | Atezolizumab + chemo ± Bevacizumab; Retifanlimab + platinum-based chemo; Pembrolizumab monotherapy (if ineligible for combination). | | **TPS < 1%** | N/A | Pembrolizumab or Cemiplimab + Carboplatin + Pemetrexed; Retifanlimab + platinum-based chemo; Nivolumab + Ipilimumab + two cycles of chemo. | ### Squamous Cell Carcinoma | PD-L1 Expression | Strong Recommendations (S) | Conditional Recommendations (C) | | :--- | :--- | :--- | | **TPS ≥ 50%** | Pembrolizumab, Cemiplimab, or Atezolizumab (monotherapy) | Pembrolizumab or Cemiplimab + Carboplatin + Paclitaxel; Nivolumab + Ipilimumab ± chemo. | | **TPS 1%–49%** | Pembrolizumab or Cemiplimab + Carboplatin + Paclitaxel | Nivolumab + Ipilimumab ± chemo; Durvalumab + Tremelimumab + chemo; Pembrolizumab monotherapy. | | **TPS < 1%** | N/A | Pembrolizumab or Cemiplimab + Carboplatin + Paclitaxel; Nivolumab + Ipilimumab + two cycles of chemo. | --- ## Analysis of Recent Clinical Trials The 2026.3.1 update specifically reviewed three significant trials. While only one led to a recommendation change, all provided critical evidence. ### POD1UM-304 (Retifanlimab) * **Intervention:** Retifanlimab (PD-1 inhibitor) + platinum-based chemotherapy. * **Key Findings:** * **Overall Survival (OS):** 18.1 months vs. 13.4 months (control). * **Progression-Free Survival (PFS):** 7.7 months vs. 5.5 months (control). * **Safety:** 63% experienced anemia; 22% experienced decreased neutrophil count. * **Impact:** Led to the addition of retifanlimab as a first-line treatment option. The panel noted it confirms a "class effect" of PD-1 inhibitors and expands treatment access. ### HARMONi-6 (Ivonescimab) * **Intervention:** Ivonescimab (PD-1/VEGF bispecific antibody) + chemotherapy vs. Tislelizumab + chemotherapy. * **Key Findings:** Significant improvement in PFS (11.1 vs. 6.9 months), but OS data is still immature. * **Clinical Note:** While promising, the panel noted the trial was limited to a Chinese population and the control arm had higher rates of brain metastases, requiring broader multiregional validation. ### BAP BRAIN (Bevacizumab) * **Focus:** Intracranial efficacy in patients with brain metastases. * **Key Findings:** Median intracranial PFS was 11.07 months with Bevacizumab + chemo vs. 7.37 months without. * **Clinical Note:** This study was conducted before immunotherapy became the standard of care, limiting its relevance to current paradigms. However, it remains an option for patients ineligible for immunotherapy. --- ## Second-Line and Subsequent Treatment For patients who have progressed after first-line therapy: 1. **Previously treated with ICIs without chemotherapy:** Offer platinum-doublet chemotherapy. 2. **Previously treated with chemotherapy and ICIs:** * **Strong Recommendation:** Docetaxel with or without Ramucirumab. * **Conditional Recommendations:** Pemetrexed, nab-paclitaxel, or Gemcitabine. * **Biomarker-specific:** Telisotuzumab vedotin (for MET overexpressing) or Trastuzumab deruxtecan (for HER2 overexpressing). --- ## Short-Answer Practice Questions 1. **What genomic alterations must be absent for a patient to be classified as "without driver alterations" according to this guideline?** * *Answer:* EGFR, ALK, BRAF, and ROS1. 2. **What was the primary clinical justification for adding Retifanlimab to the guideline recommendations?** * *Answer:* Data from the POD1UM-304 trial showing improved OS (18.1 vs. 13.4 months) and PFS compared to placebo plus chemotherapy. 3. **Why is early referral to palliative care recommended?** * *Answer:* It should be provided alongside active cancer treatment early in the course of the disease to support patient care. 4. **In which histological type is Bevacizumab specifically contraindicated?** * *Answer:* Squamous cell carcinoma (also contraindicated in cases of hemoptysis or uncontrolled hypertension). 5. **What is the "Living Guideline" numbering convention for a Major Update vs. a Rapid Update?** * *Answer:* A Major Update is indicated by a change in the second digit (e.g., 2026.2.0), while a Rapid Update is indicated by the third digit (e.g., 2026.2.1). --- ## Essay Prompts for Deeper Exploration 1. **The Evolution of PD-1 Inhibitors:** Discuss how the results of the POD1UM-304 trial regarding Retifanlimab reinforce the "class effect" of PD-1 inhibitors in NSCLC. Compare its clinical impact to existing standard-of-care agents like Pembrolizumab. 2. **The Challenges of Generalizability in Clinical Trials:** Analyze the HARMONi-6 trial results for Ivonescimab. Explain why the expert panel opted not to change current management paradigms based on this data, focusing on population demographics and control arm imbalances. 3. **Treatment Strategies for Brain Metastases:** Evaluate the findings of the BAP BRAIN and Atezo-Brain trials. Discuss the difficulties in applying historical data (pre-immunotherapy era) to modern treatment standards for NSCLC patients with intracranial disease. --- ## Glossary of Important Terms * **Bispecific Antibody:** An artificial protein that can simultaneously bind to two different types of antigen (e.g., Ivonescimab binding to PD-1 and VEGF). * **Driver Alterations:** Specific genetic mutations (like EGFR or ALK) that "drive" the growth of a cancer and can often be targeted with specific drugs. * **ECOG Performance Status (PS):** A scale used to assess how a patient's disease is progressing and how it affects their daily living abilities. * **IHC (Immunohistochemistry):** A laboratory method that uses antibodies to check for certain antigens (markers) in a sample of tissue. * **NGS (Next-Generation Sequencing):** A comprehensive technology used to determine the sequence of DNA or RNA to identify genetic alterations. * **PD-L1 (Programmed Death-Ligand 1):** A protein that acts as a "brake" to keep the body’s immune responses from being too strong; its expression levels (TPS) help guide immunotherapy selection. * **Platinum-Doublet Chemotherapy:** A standard chemotherapy regimen combining a platinum-based drug (like Carboplatin or Cisplatin) with another agent. * **TPS (Tumor Proportion Score):** The percentage of viable tumor cells showing partial or complete membrane staining for PD-L1. * **TRAEs (Treatment-Related Adverse Events):** Side effects specifically attributed to the medical treatment administered during a clinical trial.