CEO Mark Lappe Buys $2.65M of INBX Stock on Day of Positive Phase 2 Data
INBX has more than doubled off its 52-week low of $26.19 on elevated volume (5.1× avg).
Summary
CEO Mark Lappe bought $2.65 million of Inhibrx stock on the day the company announced positive Phase 2 data for INBRX-106, signaling strong insider confidence.
Key Events · Ownership and Investor Activity · INBX
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CEO Buys $2.65M in Open Market
Mark Lappe purchased 25,000 shares for $2,645,399 through the Lappe Family Trust on September 8, 2026, at prices ranging from $99.29 to $112.28.
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Purchase Coincides with Positive Phase 2 Data
The purchase occurred the same day Inhibrx reported INBRX-106 plus pembrolizumab nearly doubled response rates versus pembrolizumab alone in Phase 2 HNSCC.
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Post-Transaction Holdings
Following the purchase, Lappe's total beneficial ownership stands at 730,548 shares, including holdings in the Lappe Family Trust, Lappe Descendants' Trust, and Roth IRA.
Analysis · INBX · Life Sciences
On September 8, 2026, CEO Mark Lappe purchased 25,000 shares for $2.65 million through the Lappe Family Trust, at prices between $99.29 and $112.28. The transaction coincided with Inhibrx's announcement of strong Phase 2 data for INBRX-106 in head and neck cancer. This was a real cash outlay, not an option exercise or grant, making it a meaningful insider conviction signal from the company's top executive, especially coming on the heels of the positive clinical readout.
How filings like this one have moved
In the 30 days to Sep 10, 2026, 29.9% of the 1988 measured filings Wiseek scored 7 moved their stock by 5% or more by the next session's close. The median move was -0.12%. These are measured outcomes after filings of this importance, not a forecast for this one.
Measured one observation per ticker per day, after exclusions. Current figures: Filing Impact Tracker · open dataset
At the time of this filing, INBX was trading at $117.96 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $1.7B. The 52-week trading range was $26.19 to $155.29. This filing was assessed with positive market sentiment and an importance score of 7 out of 10.