Inhibrx Biosciences director Jon Kayyem buys $500,000 in stock

Inhibrx Biosciences' director Jon Kayyem recently bolstered his stake in the company by purchasing 5,000 shares on September 16, 2026, for a total of $500,000. Priced at $100 per share, the transaction brought the stock price to $104.73, a minor dip following a 6% week-over-week decline. Despite the short-term volatility, Kayyem’s overall stake in Inhibrx accounts for shares held by his and his family’s trusts, as well as custodial accounts for his minor children.

The insider's purchase comes amid a 295% year-over-year surge in INBX shares, though InvestingPro analysis labels the stock as overvalued relative to its Fair Value. Investors can access more in-depth valuation insights on Inhibrx through InvestingPro’s 11 ProTips and detailed financial metrics. In a separate development, Inhibrx Biosciences announced robust results from the Phase 2 HexAgon-HN trial testing its INBRX-106 drug in combination with Keytruda for head and neck cancer, achieving a 48.3% overall response rate and 9.6-month median progression-free survival compared to Keytruda’s 26.5% response rate and 4.9-month progression-free survival.

Following these promising results, H.C. Wainwright maintains a Buy rating for Inhibrx with a price target of $245.00, while Stifel also retains its Buy rating at $325.00. Citizens continues to view the company as having a Market Perform rating based on a revenue and earnings multiple analysis. The company has also expanded its credit facility with Oxford Finance LLC to $500 million, with an immediate $100 million draw and a further option to borrow $225 million.