AnaptysBio Is Flat Today. The Real Action Is Coming.

The spin-off

The separation, first announced in detail on March 27, is designed to split AnaptysBio into two distinct entities. The parent company (retaining the ANAB ticker) will become a royalty management vehicle, collecting payments from GSK's Jemperli (dostarlimab) collaboration and Vanda's imsidolimab collaboration. First Tracks Biotherapeutics will inherit the clinical-stage pipeline: ANB033 (a CD122 antagonist in Phase 1b trials for celiac disease and eosinophilic esophagitis), rosnilimab (which completed a Phase 2b trial in rheumatoid arthritis), and ANB101 (a BDCA2 modulator in Phase 1a).

First Tracks secured $145 million in private placement commitments, including $80 million in proceeds from leading investors, and is expected to launch with approximately $180 million in cash and a two-year runway. Daniel Faga, AnaptysBio's current CEO, is anticipated to lead both entities initially.

The logic is straightforward: the royalty stream from Jemperli is a predictable, high-margin cash flow asset. The biopharma pipeline is a high-risk, high-reward clinical bet. Bundling them together forces investors to value both simultaneously, and the market has historically struggled to do that well. Separating them allows each to attract its natural shareholder base.

The royalty math

The Jemperli royalty is the financial anchor. GSK reported $343 million in Q4 2025 Jemperli sales, representing greater than 13 percent quarter-over-quarter growth and implying an annualized run rate of approximately $1.4 billion. In December 2025, AnaptysBio received a one-time $75 million commercial sales milestone when Jemperli crossed $1 billion in worldwide net sales.

GSK's peak sales guidance for Jemperli exceeds $2.7 billion in monotherapy indications alone. At that level, AnaptysBio management has estimated it would receive over $390 million in annualized royalties, potentially as early as 2029. Several pivotal trials are advancing that could expand Jemperli's label: AZUR-1 (rectal cancer, top-line data expected in 2026), AZUR-4 (colon cancer, data expected Q4 2026), and JADE (head and neck cancer, data expected 2028).

The financial trajectory reflects this royalty ramp. Fourth-quarter 2025 revenue reached approximately $110 million (versus $20 million in Q2 2025), and net margins swung from negative 141.6 percent in Q1 2025 to positive 45.8 percent in Q4. The most recent earnings report, on March 3, showed EPS of $1.58 versus a consensus estimate of $0.89 and revenue of $108.25 million versus an estimate of $87.09 million.

The pipeline risk

The biopharma side is earlier stage and carries the uncertainty investors expect from clinical-stage biotech. ANB033, the lead asset for First Tracks, is in Phase 1b trials for celiac disease (two cohorts of 30 patients each) and eosinophilic esophagitis (a 50-patient cohort initiated in Q1 2026). Top-line data for the eosinophilic esophagitis trial is anticipated in 2027.

Rosnilimab, which completed a Phase 2b trial in rheumatoid arthritis, remains in the pipeline but has received less attention since AnaptysBio posted a mid-stage trial setback in ulcerative colitis. The imsidolimab program, meanwhile, is now in Vanda's hands: the FDA accepted the BLA filing for generalized pustular psoriasis in February 2026, with a target action date of December 12, 2026.

To be sure, the pipeline assets have real optionality. ANB033's "pipeline-in-a-product" potential (management's phrase) in celiac disease and eosinophilic esophagitis addresses large markets with limited treatment options. But Phase 1b data is Phase 1b data, and the spin-off means these assets will soon need to stand on their own.

The valuation gap

At $48.17, ANAB trades approximately 27 percent below the median analyst price target of $66 and 67 percent below the high target of $140 (set by Piper Sandler, which raised its target to $95 from $67 on March 31). Of 21 analysts covering the stock, 15 rate it a Buy and six rate it a Hold, with zero Sell ratings. The stock sits 34 percent below its all-time high of $73.30, reached on April 13, 2026.

The company also authorized a $100 million stock repurchase program on March 27, a signal that management views the current price as undervaluing the combined entity. Year-end 2025 cash and investments stood at approximately $311 million.

What comes next

The near-term calendar is dense. The First Tracks spin-off distribution was targeted for April 20, 2026, though the company has said only "potentially as early as late-April." Earnings on May 4 will provide the first look at Q1 2026 financials and likely the most detailed update on spin-off mechanics. The AZUR-1 top-line readout for Jemperli in rectal cancer is expected sometime in 2026 and could materially affect the royalty valuation.

The stock's flatness today is the market waiting. But the gap between the current price and the analyst consensus, combined with two imminent catalysts, suggests the wait will not be long. Whether the spin-off unlocks value or merely redistributes risk across two tickers is the question that May will begin to answer.