AnaptysBio Shares Increase Over 5% Pre-Market: Why It Happened

By Amit Chowdhry ● Aug 18, 2021
  • The shares of AnaptysBio, Inc. (Nasdaq: ANAB) increased by over 5% pre-market. This is why it happened.

The shares of AnaptysBio, Inc. (Nasdaq: ANAB) – a clinical-stage biotechnology company developing first-in-class antibody product candidates focused on emerging immune control mechanisms applicable to inflammation and immuno-oncology indications – increased by over 5% pre-market. Investors are responding positively to AnaptysBio announcing that the U.S. Food and Drug Administration (FDA) approved a second indication for GSK’s JEMPERLI (dostarlimab-gxly) for the treatment of adult patients with mismatch repair deficient (dMMR) recurrent or advanced solid tumors, as determined by an FDA-approved test, that have progressed on or following prior treatment and who have no satisfactory alternative treatment options.

JEMPERLI was generated by AnaptysBio using a proprietary somatic hypermutation (SHM) antibody platform and subsequently developed by TESARO (now a part of GSK) under a collaboration agreement. And 8 AnaptysBio-generated therapeutic antibodies have advanced into clinical development to date. 

JEMPERLI is the first AnaptysBio-generated antibody to obtain FDA approval and this is the second indication for JEMPERLI to be approved by the FDA in 2021. This indication is approved under the accelerated approval based on tumor response rate and durability of response. The continued approval for these indications may be contingent upon verification and description of clinical benefit in a confirmatory trial.

AnaptysBio had earned a $20 million milestone payment as a result of this second FDA approval for JEMPERLI in dMMR recurrent or advanced solid tumors. And earlier this year, AnaptysBio received a milestone payment of $10 million from GSK for acceptance of the BLA filing with the FDA for this second indication. 

AnaptysBio had also received $20 million and $10 million milestone payments in April 2021 for FDA and European Medicines Agency (EMA) approvals of JEMPERLI for adult patients with a certain type of endometrial cancer after having received a total of $15 million from GSK during 2020 for the FDA’s and EMA’s acceptances of these BLA and Marketing Authorisation Application (MAA) filings for JEMPERLI. 

AnaptysBio anticipates an additional $15 million and $165 million in milestone payments upon achievement of certain JEMPERLI regulatory and commercial milestones, respectively. The royalties due to AnaptysBio for JEMPERLI range from 8% to 25% of global net sales, where AnaptysBio will receive 8% of annual global net sales below $1 billion, and 12-25% of net sales above $1 billion. GSK has recently disclosed peak year annual sales estimates of £1-2 billion for JEMPERLI.

JEMPERLI is also being developed by GSK for the treatment of other tumor types and treatment settings such as currently ongoing phase III trials in recurrent or primary advanced endometrial cancer in combination with chemotherapy standard of care (RUBY) and the phase III FIRST study of platinum-based therapy with JEMPERLI and niraparib versus standard of care platinum-based therapy as first-line treatment of stage III or IV non-mucinous epithelial ovarian cancer. And JEMPERLI is being evaluated as monotherapy and in combination therapy across multiple tumor types and other cancers, including platinum-resistant ovarian cancer, non-small cell lung cancer, multiple myeloma and melanoma.

In the US, the prevalence of dMMR across solid tumors has been estimated at 14%. Mismatch repair-deficient status is a biomarker that has been shown to predict response to immune checkpoint blockade with PD-1 therapy. And tumors with this biomarker are most commonly found in endometrial, colorectal, and other gastrointestinal cancers, but may also be found in other solid tumors.

GSK is continuing to develop additional antibodies partnered with AnaptysBio, including cobolimab, an AnaptysBio-generated anti-TIM-3 antagonist antibody, and GSK4074386, an anti-LAG-3 antagonist antibody. Under the terms of the partnership, AnaptysBio is due to receive development and regulatory milestone payments for each of the first 2 indications for each of these antibodies. AnaptysBio could potentially receive a total of $1.1 billion in aggregate milestone payments under this collaboration. Plus AnaptysBio will receive royalties ranging from 4% to 8% on global net sales of cobolimab and GSK4074386 and 1% of GSK’s global net sales of Zejula.


“We are pleased that JEMPERLI has been FDA-approved for a second indication and will be available to a broader cohort of solid tumor patients. AnaptysBio’s capital-efficient business model is focused upon advancing our wholly-owned first-in-class antibodies to multiple clinical catalysts over the upcoming 18 months and is supported by milestone and royalty revenues under our GSK collaboration.”

— Hamza Suria, president and chief executive officer of AnaptysBio

Disclaimer: This content is intended for informational purposes. Before making any investment, you should do your own analysis.