Inhaled Cromolyn Sodium in Patients With Locally Advanced Lung Cancer

Scientific Background and Rationale

Lung cancer remains a leading cause of cancer-related mortality worldwide despite substantial advances in molecularly targeted therapies, immunotherapy, radiation therapy, and multimodality treatment approaches. Increasing evidence indicates that, in addition to intrinsic tumor biology, the tumor microenvironment plays a critical role in disease progression, immune evasion, therapeutic resistance, and metastatic dissemination. Consequently, there is growing interest in therapeutic strategies designed to modulate tumor-associated inflammatory and stromal processes that contribute to cancer progression.

Mast cells are resident immune cells that participate in both innate and adaptive immune responses and are increasingly recognized as important components of the tumor microenvironment. In lung cancer, mast cell infiltration has been observed within both primary tumor tissue and surrounding stromal compartments. Experimental and translational studies have suggested that mast cells may contribute to tumor-associated inflammation through the release of cytokines, chemokines, growth factors, angiogenic mediators, and proteolytic enzymes capable of influencing immune regulation, angiogenesis, extracellular matrix remodeling, and cellular proliferation.

Cromolyn sodium is an FDA-approved mast cell stabilizing agent with a long-established clinical safety profile following inhalational administration for allergic respiratory disorders. The drug inhibits mast cell degranulation and reduces the release of multiple inflammatory mediators involved in downstream immune and inflammatory signaling pathways. In addition to its effects on mast cells, preclinical investigations have suggested broader effects on inflammatory processes involving macrophages, eosinophils, neutrophils, and other immune-regulatory cell populations implicated in tumor-associated inflammation.

Preclinical studies evaluating mast cell inhibition and modulation of inflammatory signaling pathways have generated interest in the potential role of tumor microenvironment-directed therapeutic strategies in solid tumors. Although the clinical significance of these observations remains uncertain, available experimental data provide a biologically plausible rationale for exploratory clinical investigation of cromolyn sodium in lung cancer.

The pulmonary route of administration offers additional scientific rationale for evaluation in this setting. Inhaled drug delivery permits direct deposition of therapeutic agents within the respiratory tract and may facilitate local exposure within pulmonary tissues while limiting systemic drug exposure. Administration by dry powder inhaler may provide efficient pulmonary delivery and represents a practical, non-invasive method of drug administration that can be implemented in both clinical and home-based settings.

Cromolyn sodium has demonstrated a favorable safety profile during decades of clinical use. Systemic absorption following inhalation is limited, systemic toxicity is uncommon, and the drug is not associated with many of the adverse effects characteristic of conventional cytotoxic anticancer therapies. Nevertheless, the use of inhaled cromolyn sodium for the treatment of lung cancer remains investigational and has not been established as safe or effective for this indication.

Given the established clinical safety profile of inhaled cromolyn sodium, its biologic activity as a mast cell stabilizer, the emerging understanding of inflammatory and stromal mechanisms in lung cancer progression, and the potential advantages of localized pulmonary drug delivery, a pilot clinical investigation is warranted to evaluate the safety, feasibility, tolerability, and preliminary clinical activity of inhaled cromolyn sodium in participants with locally advanced lung cancer.

Safety Considerations

Participants enrolled in this study will undergo protocol-defined safety monitoring throughout the treatment and follow-up periods. Safety assessments will include evaluation of treatment-emergent adverse events, respiratory symptoms, hypersensitivity reactions, clinically significant laboratory abnormalities, and other changes in clinical status. Given the investigational nature of this treatment approach, ongoing safety surveillance will be conducted throughout study participation.