Oyster Therapeutics, a London-based company focused on tau-targeting protein degraders, raised $60 million in an extension of its Series A round to advance oral brain drugs designed to destroy disease-causing forms of tau. The funding supports its approach using a linker that splits upon entry into the body to improve brain penetration and address limitations seen in earlier degrader formats. The company is pursuing a degradation strategy rather than conventional tau-binding inhibition, with an emphasis on sparing healthy tau isoforms. Oyster did not disclose timing for clinical entry. Still, the announcement arrives in a crowded tau landscape after multiple high-profile failures, increasing the bar for differentiation. Oyster’s CEO Robert Johnson argued that combining amyloid and tau-directed therapies could be required for meaningful disease modification, reflecting investors’ ongoing interest in tau biology despite repeated trial disappointments.