Daiichi rekindles its sting

Development of antibody conjugates that use a STING agonist payload might be given a second wind after Daiichi Sankyo's revelation that it plans to take one into the clinic later this fiscal year. In its earnings presentation on Thursday the Japanese company presented DS3610, a molecule that combines its "original STING agonists" with an antibody, and incorporates Fc region modification to reduce risk of cytokine release. The target of the MAb employed by DS3610 hasn't been disclosed; moreover, Daiichi wasn't widely known to have worked on STING agonists in the past. Neither STING agonists – where Pfizer's PF-07820435 is a notable discontinuation – nor STING-based ADCs have had an easy ride. The latter saw three deals in 2022, involving Merck KGaA and Mersana, Exelixis and Ryvu, and GSK and Mersana, but Takeda subsequently discontinued plozalizumab plevistinag after this showed futility in phase 1/2, while Mersana's calotatug ginistinag spent seven months on clinical hold in 2023 after a fatal drug-related adverse event. When DS3610 enters the clinic it and calota-G will be the only two STING-payload ADCs in human trials, according to OncologyPipeline.

ADCs using STING agonist payloads

Source: OncologyPipeline.