Endometriosis-associated pain is an important driver of opioid use in women. Endometriosis is and estrogen sensitive, angiogenesis dependent disease that affects ~10% of women of childbearing age and is found in half of women with chronic pelvic pain. Endometriosis increases the likelihood of chronic opioid use, opioid dependence/abuse, and opioid overdose. Endometriosis is currently treated with NSAIDS, hormonal therapy targeting estrogen production, and surgery, but these options are not durably effective for ~30% of patients. Thus, new targets are needed. CMG2 is an integrin-like extracellular matrix receptor that we have shown regulates angiogenesis. It is also overexpressed in endometriosis tissue vs. normal endometrium. In mouse models, published work and our preliminary data show that treatment with CMG2 antagonists that we discovered (PGG, PGM) decreases lesion incidence, growth, and endometriosis-associated pain. These observations suggest that CMG2 may be a useful target for the treatment of endometriosis-associated pain. However, key gaps in our understanding of CMG2 biology would slow any development program with CMG2 as a target. The first key gap is that the cell type whose targeting resulted in decreased pain upon CMG2 antagonist treatment is unclear. Second, the molecular mechanism underlying CMG2 signaling in endometriosis is not known. Finally, both the maximum efficacy and, importantly, safety of CMG2 targeting is not known. We propose to fill these gaps by using cell-type-specific CMG2 knockout mice to identify cell types where CMG2 expression supports endometriosis lesion growth and pain. Because CMG2 lacks any catalytic domains, we hypothesize that CMG2 signals via differential protein interaction. Then, expression of CMG2 in appropriate cells in human lesions will be confirmed. Next, we will use proximity proteomics to identify downstream molecules that differentially interact with CMG2 ±inhibitor. Candidate mediators of CMG2 signaling will then be confirmed using CRISPR knockout and cell-based assays of CMG2 function. Finally, we will evaluate safety and efficacy of CMG2 targeting in a mouse model using a well-characterized, high- specificity CMG2 inhibitor. Throughout ex vivo and in vivo assays, RNAseq and scRNAseq will be used to identify transcriptional signatures of CMG2 blockade, both to validate in vitro assays and to generate potential pharmacodynamic markers of CMG2 inhibitors. Completion of the proposed work will validate CMG2 as a target for the treatment of endometriosis- associated pain. It will also provide key insights into endometriosis pathophysiology that will enable the generation of novel therapeutics and may identify additional targets for treatment of the disease. Development of such drugs will improve the lives of many women and decrease the use of opiods to treat this disease, thereby improving many lives.

Endometriosis-associated pain is a key driver of opiate use in the female population. We propose to validate capillary morphogenesis gene 2 (CMG2) as a target for non-opioid pain relief by identifying the cellular and molecular mechanisms by which it affects disease and by measuring the efficacy and safety of CMG2 targeting in mice.