Oyster Therapeutics raised $60 million in an extension of its Series A to develop oral protein-degrader drugs targeting disease-causing forms of tau, a new financing step for the rapidly growing tau-franchise field. The company is pursuing a degradation approach rather than classic tau inhibition, with its lead program using a linker intended to split after entering the body to improve cell-membrane penetration. The company’s announcement underscores investor appetite for next-generation approaches after mixed clinical progress for some tau-targeting mechanisms, while emphasizing differentiated chemistry and delivery strategy. Oyster did not provide a clinic entry timeline in the report. For the sector, the deal reinforces how therapeutic modality competition—particularly tau degraders—remains tightly linked to capital access and platform differentiation.