Immuneering is a clinical-stage oncology company focused entirely on developing a novel class of cancer drugs it calls Deep Cyclic Inhibitors (DCIs). Its lead and only active drug candidate is atebimetinib, an oral, once-daily MEK inhibitor built around a pulsatile pharmacological approach — a short plasma half-life creates cycles of high-peak inhibition followed by near-zero drug levels, designed to hit tumors hard while allowing healthy cells to recover. Immuneering argues this mechanism avoids the chronic toxicities and adaptive resistance that limit existing MEK inhibitors. The primary target indication is first-line metastatic pancreatic ductal adenocarcinoma (PDAC), a cancer with roughly a 3% five-year survival rate in metastatic patients. Phase 2a data in 34 patients showed 64% overall survival at 12 months versus roughly 35% for the standard of care chemotherapy regimen. Immuneering is now preparing MAPKeeper 301, a global Phase 3 registrational trial in first-line PDAC targeting roughly 510 patients, with first patient dosing expected in mid-2026. Atebimetinib also holds FDA Fast Track designation for first- and second-line PDAC and NRAS-mutant melanoma. Beyond PDAC, Immuneering plans combination trials in RAS-mutant non-small cell lung cancer with Regeneron and Eli Lilly. The company has no product revenue and is funded entirely by capital raises, including a $25M investment from Sanofi, with a cash runway extending into 2029.