ABL Bio held back its top Alzheimer’s targets. GSK still signed a $2.7 bil. licensing deal.

Before inking its blockbuster deal with GSK on Saturday, ABL Bio said it had been approached by an unnamed pharma giant with an enticing pitch: let them license Grabody-B, the company’s platform for delivering drugs across the blood-brain barrier, for use in an anti-amyloid antibody.

But the terms, CEO Lee Sang-hoon said, would have locked up the entire amyloid-beta target—every epitope, not just the one they were working on.

“It made no sense,” Lee said during a post-deal debrief on Wednesday, just two days after the company announced its 4.1 trillion won ($2.73 billion) deal with GSK. Agreeing to blanket exclusivity, he explained, would have shut down any future partnerships—even those targeting different parts of the same protein. “The field is too dynamic for that,” he added. “We still don’t know which epitope makes for the best drug. That was a red flag.”

That red flag became a blueprint. 

Three months after J.P. Morgan Healthcare Conference 2025, ABL Bio landed one of the largest licensing deals in Korean biotech history—granting GSK rights to apply its Grabody-B platform—including for the insulin-like growth factor 1 receptor (IGF1R)—across a slate of undisclosed central nervous system (CNS) targets. Crucially, the agreement excluded amyloid-beta and tau—two of what Lee called the most “prized targets” in Alzheimer’s drug development. 

“That carve-out wasn’t a footnote,” he said. “It was the deal.”

GSK, in an email to Korea Biomedical Review, confirmed it had been in discussions with ABL for three years leading up to the agreement but declined to comment on specific negotiation details. According to Lee, the back-and-forth got tense in the final stretch.

The British pharma, he said, continued pushing for tau until March, right as the contract was being finalized. “We were in Philadelphia, going over the contract line by line, but we held firm. Amyloid and tau are still ours.”

The strategic shift opens the door to epitope-specific licensing—a model that lets ABL slice each protein target into multiple partnerships without overlap. It's the same approach that helped Alteogen turn its hyaluronidase platform into a licensing machine.

“In this deal, we structured non-exclusive rights for Alzheimer’s targets like amyloid and tau at the epitope level,” Lee said. “It’s the same logic Alteogen used with Merck and AstraZeneca—one product, one license.”

ABL gave up none of its flagship targets. Instead, GSK walked away with exclusive rights to a basket of novel CNS proteins. "Some were so new that we hadn’t even heard of them,” he said. While the full list and milestone structure remain under wraps, each target, once chosen, is locked. “If they pick Target 1, no other partner can use Grabody-B for that target,” he said.

That leaves amyloid, tau, and “every other unclaimed epitope” still on the table. According to Lee, one major pharma paused talks during JPM 2025 but circled back after the GSK announcement, and among the handful of top-tier CNS players who could realistically license the platform, Lee estimated there are “maybe 20 to 30 companies” globally. “We’re just getting started.”

The GSK deal also marks a turning point in modality. Grabody-B was initially developed for antibodies—but now ABL is testing its shuttle with RNA-based therapies, including siRNA and antisense oligonucleotides, in partnership with U.S. biotech Ionis Pharmaceuticals. Results have been strong enough that the company is preparing a paper for publication, Lee said.

“We used to think BBB shuttles were just for antibodies,” he said. “Now we’re delivering RNAi therapeutics to the brain.”

That angle clicked with GSK, which has invested heavily in oligonucleotide programs for Parkinson’s and other neurodegenerative diseases, including collaborations with Massachusetts-based Wave Life Sciences and Vesalius Therapeutics. The deal came together fast—without a material transfer agreement (MTA), which is usually standard for tech evaluations.

With Sanofi, Lee recalled, the MTA stage alone took six months, requiring extensive in vivo studies just to prove brain penetration. “Most companies spend half a year just on the MTA,” he said. “This time, we closed in under three.”

That speed, he added, signals confidence in the platform. “We’re at a stage now where future deals may not need an MTA at all,” Lee said. “That changes the tempo completely.”

Still, the real win, in his view, is what wasn’t signed away.

“Last year, we told investors we were holding back,” he said. “Now you see why. The real value isn’t in one deal. It’s in how many more we can make.”