CRO-67 has anti-cancer activity in pancreatic tumor cells and stromal cancer-associated fibroblasts

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy that urgently needs more effective therapies. Cancer-associated fibroblasts (CAFs) contribute to the aggressive and chemo-resistant nature of the disease by creating a drug-impeding fibrotic microenvironment. We developed novel compounds, the racemate CRO-05 and its active enantiomer CRO-67, which target both pancreatic tumor and CAF cells with robust anti-cancer activity. These compounds were designed using rational medicinal chemistry based on chromans, a class of anti-cancer drugs. Their therapeutic potential and efficacy were assessed in a clinically relevant patient-derived PDAC tumor explant model, which mimics the disease's 3-dimensional complexity. CRO-67 treatment in these explants significantly reduced tumor cell and αSMA⁺ CAF frequency, decreased cell proliferation and increased cell death. CRO-67 also significantly decreased cell proliferation and enhanced apoptosis by inhibiting cell cycle progression through G2/M phase in PDAC cells and patient-derived CAFs in vitro. CRO-67 treatment of orthotopic PDAC tumors in mice significantly reduced tumor growth in tumors with active growth (> 150% growth at endpoint), and remodeled tumor stroma (reduced αSMA⁺ CAF frequency, loosened tumor fibrosis and normalized tumor vasculature). Finally, CRO-67 sensitized PDAC cells to multiple standard-of-care chemotherapeutics in vitro, paving the way for future combination therapy development and validation.