Fakzynja (defactinib)

Genetic knockout of FAK or pharmacological inhibition using defactinib or PF-573228 effectively suppressed the sorafenib-induced upregulation of AKT and HMGCR...Importantly, another RAF-targeting multikinase inhibitor, regorafenib, also triggered a similar adaptive FAK-cholesterol response, suggesting that this may be a common resistance mechanism shared among RAF inhibitors...Collectively, this study systematically uncovers a new mechanism of sorafenib resistance in HCC: downregulation of RhoE drives cholesterol biosynthesis through activation of the FAK/AKT axis, thereby activating the SHH pathway and upregulating GLI1. These findings provide a strong theoretical rationale for the use of FAK inhibitors to overcome resistance and highlight the dual clinical relevance of the cholesterol biosynthesis gene signature-both as a molecular marker for predicting resistance and as a potential guide for personalized treatment strategies in HCC.

Notably, the recent US Food and Drug Administration approval of the avutometinib/defactinib combination for KRAS-mutated recurrent LGSOC marks a significant milestone in targeted therapy for this disease. Despite these advances, challenges remain in optimizing sequencing strategies and overcoming acquired resistance. This review addresses the importance of understanding the distinct pathophysiology of LGSOC, diagnostic challenges, limitations of conventional treatments, and evolving therapeutic approaches in LGSOC.

FAK inhibition was shown to suppress non-angiogenic vascularization. Defactinib has the potential to serve as a novel treatment for malignant breast cancer which is resistant to conventional therapies.

Therefore, despite the pleiotropic mechanisms of Rac1-driven MAPKi resistance, we find that combined inhibition of RAF and MEK with the RAF/MEK clamp avutometinib and FAK with the FAK inhibitor defactinib is a promising approach for suppressing the growth of Rac1-driven melanoma cells. Thus, the avutometinib plus defactinib combination, which is currently being investigated for brain metastatic cutaneous melanoma may also have utility against Rac1-driven MAPKi-resistance in heavily pre-treated, advanced disease.

P1, N=14, Active, not recruiting, Emory University | Recruiting --> Active, not recruiting

P2, N=6452, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Dec 2025 --> Dec 2026 | Trial primary completion date: Dec 2025 --> Dec 2026

Avutometinib is a dual RAF/MEK clamp, whereas defactinib and VS-4718 are focal adhesion kinase (FAK) inhibitors...Tissue obtained from a LGSOC patient wild-type for KRAS/NRAS/BRAF mutations in progression after chemotherapy/anastrozole was transplanted into female CB17/lcrHsd-Prkdc/SCID mice (PDX-OVA(K)250)...The addition of fulvestrant to avutometinib/FAKi is well tolerated in vivo and enhances the antitumor activity of avutometinib/FAKi in a LGSOC-PDX model with acquired resistance to chemotherapy/aromatase inhibitors. These results support the clinical evaluation of avutometinib/defactinib in combination with fulvestrant or an aromatase inhibitor in patients with recurrent LGSOC.

P2, N=42, Active, not recruiting, Washington University School of Medicine | Trial primary completion date: Sep 2025 --> Dec 2025

To our knowledge, this is the first report demonstrating the role of FAK and its inhibition across both normal and cancerous bladder urothelial models. This study highlights the critical role of FAK in the progression of human bladder cancer and establishes a foundation for exploring FAK inhibition as a potential therapeutic approach in bladder cancer treatment.

Combining BMS-986158 with the FAK inhibitor Defactinib had synergistic effects, reducing EwS cell proliferation, survival, and invasion in vitro, and significantly inhibited tumor outgrowth in vivo. Our studies identify BET and FAK inhibition as a rational combination therapy worthy of further investigation for EwS, and demonstrate that defining emergent mechanisms of epigenetic drug tolerance can identify new vulnerabilities that can be therapeutically targeted.

P1/2, N=40, Active, not recruiting, Verastem, Inc. | Recruiting --> Active, not recruiting

Re-expression of DIRAS3 and treatment with defactinib produced tumor regression in xenograft models. Our findings suggest that ECM components in the tumor microenvironment like FN enhance the activities of β1 integrin, FAK, and AKT to inhibit DIRAS3-induced autophagic cell death, thereby promoting ovarian cancer cell survival.