Verastem is a small biopharmaceutical company focused on developing and commercializing treatments for cancers driven by the RAS/MAPK signaling pathway. Its core commercial product is the AVMAPKI FAKZYNJA CO-PACK (avutometinib + defactinib), an oral combination therapy that received FDA accelerated approval in May 2025 as the first treatment specifically approved for adults with KRAS-mutated recurrent low-grade serous ovarian cancer (LGSOC). LGSOC is a rare cancer with roughly 6,000–8,000 patients in the U.S., and the CO-PACK targets the approximately 30% of those patients who carry a KRAS mutation. The CO-PACK works by simultaneously blocking two resistance pathways: avutometinib inhibits MEK kinase and upstream RAF reactivation, while defactinib inhibits FAK, a compensatory resistance mechanism. Verastem sells the CO-PACK exclusively through specialty pharmacies and distributors, targeting gynecologic and medical oncologists. Revenue is driven by the number of patients on therapy and treatment duration. The company licenses avutometinib from Chugai Pharmaceutical and defactinib from Pfizer, paying royalties to both, and outsources all manufacturing to CMOs. Beyond the approved LGSOC indication, Verastem is pursuing label expansion to KRAS wild-type LGSOC patients and geographic expansion into Japan and Europe. The company is also developing VS-7375, an oral KRAS G12D inhibitor licensed from GenFleet, which Verastem views as its primary long-term growth driver across pancreatic, lung, and colorectal cancers. Verastem is pre-profitability, using CO-PACK revenue to partially fund its ongoing clinical programs.