- GlaxoSmithKline will pay Iteos Therapeutics $625 million in cash for rights to an experimental drug aimed at a cellular target, known as TIGIT, that's viewed as a potential path to broadening the reach of cancer immunotherapy.
- Per terms of the deal, GSK licensed rights outside of the U.S. for a drug in Phase 1 testing for a variety of tumors. GSK and iTeos will split any future U.S. profits as well as global development costs in the deal, which includes an additional $1.45 billion in milestone payments. iTeos shares climbed 39%, to about $28 apiece, in early trading Monday.
- The deal is the latest sign of large pharmaceutical companies' growing interest in TIGIT. Roche, Merck & Co., Bristol Myers Squibb and Gilead have all either developed or acquired such drugs over the past few years. Early clinical data has indicated their potential to boost the effects of so-called checkpoint inhibitors, which, depending on the tumor type, may still only help a minority of patients.
Compared to cancer immunotherapy leaders Merck, Roche and Bristol Myers Squibb, GlaxoSmithKline is a latecomer to the lucrative field.
Historically known best for vaccines and drugs for asthma and HIV, the British drugmaker was seventh to market when regulators cleared its checkpoint blocker Jemperli for endometrial cancer in April. The other six are already cleared for several cancer types and the top seller, Merck's Keytruda, earned more than $14 billion last year.
While GSK has made strides in oncology, the company is still viewed as having a long way to go. A PARP inhibitor called Zejula, which, like Jemperli, was also acquired in a $5.1 billion buyout of Tesaro in 2019, has vastly underperformed Merck and AstraZeneca's rival Lynparza. Blenrep, a multiple myeloma medicine developed with SeaGen, could be topped by an emerging group of antibody drugs and cell therapies. And two of GSK's top prospects, feladilimab and bintrafusp alfa, failed in clinical testing.
Monday's deal is another example of GSK risking a large sum to jump into a very competitive area of oncology. The alliance is centered around EOS-448, a member of a class of drugs that block a protein called TIGIT. These types of antibodies have shown promise as a way to boost the share of patients who respond to checkpoint therapy. iTeos, a Belgian biotech that went public last year, owns one of only a handful of them to reach testing in humans.
GSK's deal is a bet, however, on an unproven drug with several large competitors and for which early data hasn't appeared clearly superior. Results disclosed this year, for instance, showed only one patient with an advanced solid tumor in an early stage trial had a partial response to monotherapy treatment. Many more had stable disease, giving the drug a similar early profile to other TIGIT blockers.
The data are "in line with the rest of the TIGIT class," wrote SVB Leerink analyst Daina Graybosch wrote in a recent research note, "but below 'best-in-class' expectations set by iTeos management," who had touted the drug as potentially better than its rivals. Prior to Monday's announcement, iTeos shares had fallen about 40% from their all-time highs in March.
GSK seems to view the drug as a possible cog for several potential immunotherapy combinations, among them a dual regimen with Jemperli that's expected to begin Phase 1 testing next year. iTeos intends to study its drug against head and neck cancers as well as lung. It's also evaluating potential trials in skin cancer and multiple myeloma, said chief medical officer Joanne Lager.
iTeos is already behind the competition, though. Four late-stage TIGIT combination trials are already underway in lung cancer, for example, a tumor type in which early results have so far been the strongest.
iTeos has been testing EOS-448 alongside Keytruda. A Phase 2 study should begin within the next few months, executives said on a conference call on Monday. Despite the GSK deal, Lager said the company still has the option to evaluate regimens with other checkpoint inhibitors, too.