Developer of a new cancer therapy Arcellx saw its price rise 77% in a day. What's the reason?

Shares of Arcellx, a mid-cap developer of cell therapy for blood cancer, soared 77% on February 23 to a new all-time high. A major partner, Gilead Sciences, plans to buy the company at a significant premium to its market value. For investors, this is a signal that leading market players increasingly prefer not to cooperate with smaller companies, and fully own assets, said broker Noble Capital Markets.

Quotes of Arcellx jumped on Nasdaq on February 24 by more than 77% - to $113.75 per paper. This became the record closing price for the whole time of shares circulation on the exchange.

Investors reacted to a report that the mid-cap developer plans to be acquired by its major partner Gilead, which already owns 11.5% of its capital. The deal values Arcellx at $7.8 billion, or $115 per share. That, as of Feb. 20, represents a 68% premium to the weighted average price of the company's securities over the previous 30 days, according to the report.

Under the terms of the agreement, current Arcellx shareholders could receive an additional $5 per share if sales of its experimental drug anito-cel, designed to treat multiple myeloma, reach $6 billion by 2029.

Gilead will buy the mid-cap developer's shares in a tender offer. The deal will take place if the pharma giant manages to raise at least half of Arcellx's securities and if it is approved by regulators. The parties expect to finalize all procedures in the second quarter of 2026.

Gilead shares were down 1% in trading on Feb. 23.

Arcellx, along with Gilead subsidiary Kite, is developing a next-generation cell-based (or CAR-T) therapy. Its lead drug candidate is called anito-cel and serves as a therapy for multiple myeloma. It is an aggressive blood cancer, and existing treatments cannot completely defeat it - only relegate it to chronic status. Eventually, the disease relapses, and patients require additional courses of therapy. Because of this, the effectiveness of treatment is often reduced, and toxicity increases. As a consequence, the number of treatment options available to patients is reduced.

Arcellx solves these problems, the company writes: clinical studies show that it is effective and safe.

The company has filed an application with industry regulator FDA to register it as a fourth-line therapy for multiple myeloma - when the first three regimens have proven ineffective or stopped working. The FDA is expected to make a ruling in December 2026, Arcellx said in a statement.

It also states that in addition to anito-cel Gilead will acquire the D-Domain CAR platform - for future CAR T-cell therapy programs.

To investors, this acquisition shows: in the late stages of development, large pharmaceutical companies are increasingly seeking full ownership of assets in the field of oncology, writes Noble. Thanks to the deal, Gilead will, among other things, eliminate milestone payments and royalty obligations, which will simplify its financial statements.

After the announcement of the planned acquisition, at least three Wall Street analysts downgraded Arcellx to "hold," Yahoo Finance shows. Now this is the most popular recommendation for the company's shares: 12 analysts adhere to it, six more advise to buy shares of mid-cap developer, according to MarketWatch. Just a month ago, the situation was different: 17 "buy" and only two "hold" recommendations. The average target price is $112.15, which is almost in line with current quotes.