Randomized, Double-Blind, Placebo-Controlled Parallel-Group, Multi-Center Supplementary Clinical Trial on the Efficacy and Safety of Longqi Capsules for the Treatment of Advanced Non-Small Cell Lung Cancer (Phlegm-Stasis Obstructing the Lung Syndrome)

INTERVENTION: Experimental Group:Longqi Capsules, oral. Take 4 capsules per dose, three times a day. Take after meals, half an hour after eating.;Control Group:Longqi Capsules Simulator, oral administration. Take 4 capsules at a time, 3 times a day. Take after meals, half an hour after eating.; CONDITION: Advanced non‐small cell lung cancer PRIMARY OUTCOME: Main symptoms of lung cancer [cough, sputum production, dyspnea (shortness of breath), chest tightness] NRS(numerical rating scale) total score weekly average decrease compared to baseline.; SECONDARY OUTCOME: Main symptoms of lung cancer [cough, sputum production, shortness of breath (breathlessness), chest tightness] NRS (numerical rating scale) total score, weekly average score, and decrease from baseline.;Main symptoms of lung cancer [cough, expectoration, dyspnea (breathlessness), chest tightness] improvement rate.;Main symptoms of lung cancer [cough, expectoration, shortness of breath (dyspnea), chest tightness] disappearance time and disappearance rate.;Main symptoms of lung cancer [cough, expectoration, shortness of breath (breathlessness), chest tightness] NRS (numerical rating scale) total maximum score decrease from baseline;Reduction from baseline in the weekly mean NRS (numerical rating scale) score for individual lung cancer symptoms and the improvement rate.;Time and rate of disappearance of individual symptoms in lung cancer.;The change in Traditional Chinese Medicine (TCM) syndrome scores from baseline;Change in scores from baseline for the Quality of Life (QoL) Questionnaires (EORTC QLQ‐C30 and EORTC QLQ‐LC13);Emergency Medications Usage (including number of users, usage rate, number of uses, and quantity used);Overall Survival (OS);Progression‐Free Survival (PFS); INCLUSION CRITERIA: (1) Meets the diagnostic criteria for non‐small cell lung cancer (squamous or non‐squamous histological examination is allowed. Mixed tumors will be classified according to the predominant cell type; if small cell or neuroendocrine components are present, eligibility is not met); (2) According to the International Association for the Study of Lung Cancer and the 9th edition of the Union for International Cancer Control TNM staging for lung cancer, patients with stage III B/III C (locally advanced), or stage IV (metastatic or recurrent) disease; (3) Failed standard treatment, unable to tolerate standard treatment, or unwilling to receive standard treatment, but not suitable for or refusing surgery, radiotherapy, chemotherapy, molecular targeted therapy, or immunotherapy; (4) Meets the diagnostic criteria for phlegm and blood stasis obstructing the lung syndrome in traditional Chinese medicine; (5) During the screening/induction period, at least two of the