AnaptysBio Files Legal Complaint Against GSK and Tesaro

AnaptysBio ( (ANAB) ) has provided an update.

On November 20, 2025, AnaptysBio filed a complaint in Delaware Chancery Court against TESARO, Inc. and GlaxoSmithKline (GSK), alleging breaches of their Collaboration and Exclusive License Agreement. The dispute centers around the development and commercialization of dostarlimab, a promising PD-1 antagonist used in cancer treatment. AnaptysBio claims that Tesaro and GSK have violated exclusivity and diligence obligations by conducting clinical trials with competing products, thus undermining dostarlimab’s commercial potential. This legal action seeks to reclaim rights to dostarlimab and address the alleged breaches, which have significant implications for AnaptysBio’s strategic positioning and stakeholder interests.

The most recent analyst rating on (ANAB) stock is a Hold with a $42.00 price target. To see the full list of analyst forecasts on AnaptysBio stock, see the ANAB Stock Forecast page.

Spark’s Take on ANAB Stock

According to Spark, TipRanks’ AI Analyst, ANAB is a Neutral.

AnaptysBio’s overall stock score is primarily impacted by its weak financial performance, characterized by significant losses and a precarious balance sheet. While technical analysis shows bullish momentum, overbought conditions suggest caution. The negative P/E ratio further reflects valuation challenges.

To see Spark’s full report on ANAB stock, click here.

More about AnaptysBio

AnaptysBio is a clinical-stage biotechnology company focused on delivering innovative therapeutics for autoimmune and inflammatory diseases. The company has developed and out-licensed multiple therapeutic antibodies, including cancer therapies such as dostarlimab, through collaborations with other biopharmaceutical companies.

Average Trading Volume: 610,049

Technical Sentiment Signal: Buy

Current Market Cap: $1.15B

For detailed information about ANAB stock, go to TipRanks’ Stock Analysis page.