Lifirafenib hydrochloride (BGB-283 hydrochloride) is a novel, reversible B-RAFV600E inhibitor with antitumor activity. Lifirafenib has shown potent antitumor activity against solid tumors with B-RAFV600E mutations, such as melanoma, thyroid cancer , and low-grade serous ovarian cancer. Lifirafenib exhibits selective cytotoxicity in vitro, preferentially inhibiting the proliferation of cancer cells with B-RAFV600E and EGFR mutations/amplification. Lifirafenib can achieve dose-dependent inhibition of tumor growth in animal models, accompanied by partial and complete tumor shrinkage.