THERAPEUTIC SINGLE DOMAIN ANTIBODY

Smart overview of the Invention

A pharmaceutical composition featuring a single-domain antibody, identified as SEQ ID NO:1, is designed to inhibit KRAS GTPase activity and the phosphorylation of STAT3. The composition includes a pharmaceutically acceptable carrier and demonstrates dual intracellular activity. By targeting KRAS, the antibody disrupts downstream signaling pathways, specifically decreasing phosphorylation of ERK1/2. Additionally, it reduces tumor cell surface PD-L1 expression and VEGF production, contributing to its therapeutic effects.

Blood-Brain Barrier Penetration and Activity Duration

The single-domain antibody is capable of crossing the blood-brain barrier following systemic administration, achieving penetration within approximately 15 minutes. It exhibits sustained biological activity in vivo, maintaining its effects for at least seven days post-administration. Pharmaceutically acceptable carriers for the antibody include saline, phosphate-buffered saline, Ringer's solution, dextrose solution, and human serum albumin, ensuring compatibility with various delivery methods.

Treatment of KRAS-Mutant Cancers

Methods for treating KRAS-mutant cancers involve administering the single-domain antibody to inhibit KRAS GTPase activity and STAT3 phosphorylation. This approach is particularly effective for cancers with KRAS (G12D) or KRAS (G13D) mutations, such as pancreatic cancer and triple-negative breast cancer. In experimental models, administration of the antibody has resulted in tumor regression, demonstrating its potential efficacy in clinical settings.

Enhancing Anti-Tumor Immunity

The antibody also enhances anti-tumor immunity by reducing PD-L1 expression on tumor cells, a process mediated by the inhibition of STAT3 signaling. PD-L1 reduction occurs within 24 to 48 hours following administration, contributing to the immune system's ability to target and destroy cancer cells. These effects underscore the antibody's role in modulating immune responses against tumors.

Research and Clinical Implications

The development of this single-domain antibody represents a significant advancement in targeting intracellular signaling proteins like KRAS and STAT3, which have been traditionally considered undruggable. By overcoming pharmacokinetic and toxicity challenges, this antibody offers a promising therapeutic option for difficult-to-treat cancers. Ongoing research and clinical trials will further elucidate its potential and optimize its application in cancer therapy.