More than two years into its partnership with China’s Kelun-Biotech, Merck has made further choices on which part of the sprawling early-stage pipeline it wants to move forward.
The pharma giant will pay $37.5 million to license SKB571, which Kelun describes as a bispecific ADC “that primarily targets various solid tumors such as lung cancer and gastrointestinal tumors.” Meanwhile, the program it’s dropping — SKB315 — targets CLDN18.2.
Both programs are early-stage assets well behind the most advanced program in the deal, namely the TROP2-targeting ADC SKB264, which is also known as sac-TMT. Kelun disclosed the latest updates to the deal in a filing to the Hong Kong stock exchange.
The partners have been “adjusting and optimizing our scope of collaboration” regarding the early-stage programs “from time to time,” Kelun wrote. In October, Merck also opted not to pick up two of the preclinical ADCs it had initially reserved from Kelun.
As part of the collaboration, Kelun said it has carried out a Phase 1a trial of SKB315 in China, where it demonstrated “positive efficacy and acceptable safety profile” in gastric cancer with high CLDN18.2 expression.
“Given the significant population of GC patients in China, we have confidence in the market prospects of SKB315 in China,” it wrote. “We will continue to expedite its development in China and explore suitable expansion into overseas markets.”
As for SKB571, Kelun noted an IND application “is expected to be submitted in the near future.”
Merck inked its first tie-up with Kelun in May 2022, and later in that year signed two more deals to get its hands on more programs, with the last one carrying a whopping $9.3 billion in potential milestones. For the lead candidate sac-TMT, Kelun said Merck has begun 10 Phase 3 clinical studies, testing it either as a monotherapy or in combination with Keytruda or other agents.
Kelun has received $90 million worth of milestone payments from Merck in the first half of 2024, according to the filing.