Perceptive Advisors' $80M Arcellx Sale Highlights Regulatory and Competitive Pressures

What happened

Perceptive Advisors sold approximately 1 million Arcellx shares in Q4 2025, realizing about $80 million and reducing their position value by $107 million due to both sales and stock price declines. This move occurred as Arcellx's stock faced pressure from emerging rival drugs, particularly Carvykti, which has established durability and market presence in multiple myeloma. Arcellx's lead asset, anito-cel, shows strong clinical data but has not yet filed for FDA approval, adding regulatory uncertainty to its commercial timeline. The company's financials reveal widening operating losses and collapsing collaboration revenue, despite a cash runway into 2028 from $576 million in reserves. The sale signals that sophisticated investors are growing cautious about Arcellx's ability to navigate approval hurdles and compete effectively in a crowded CAR-T market.

Implication

Investors should interpret Perceptive Advisors' sale as a warning that large funds are reducing positions due to delayed BLA submission and intense rivalry from Carvykti. Arcellx's stock price near $68 embeds high expectations for a 2026-2027 launch, but with no BLA filed and competitors advancing, the downside risk toward the bear case $40 is increasing. Cash reserves provide liquidity, but operating cash burn remains elevated, and any regulatory setbacks could force dilutive financing. Maintain a 'WAIT' stance, seeking entry below $55 or after clear regulatory milestones like BLA acceptance to mitigate binary uncertainty. Additional large-scale selling could drive further price erosion, emphasizing the need for patience in this high-risk, single-asset story.

Thesis delta

The sale reinforces the existing 'WAIT' rating but does not shift the core thesis; it underscores that regulatory delays and competitive threats are now impacting investor sentiment. It increases the urgency for Arcellx to file its BLA to restore confidence, yet the recommendation remains to hold off until a pullback or clearer de-risking events emerge.