Boston-based Life Biosciences has closed a USD 80 million Series D financing round to advance ER-100, its lead gene therapy candidate for optic neuropathies, and to continue development of its Partial Epigenetic Reprogramming (PER) platform. The round was fully subscribed, though the company did not disclose the identities of participating investors.
Proceeds are intended to fund operations through the second half of 2027, with a primary focus on completing the Phase I clinical trial of ER-100 that was initiated in Q1 2026 as per company disclosure. The company also indicated that funding will support the identification and advancement of additional pipeline candidates derived from the PER platform across further age-related disease indications.
ER-100 is being evaluated in a Phase I trial (NCT07290244) enrolling patients with open-angle glaucoma and non-arteritic anterior ischemic optic neuropathy. The study is assessing safety and tolerability as primary endpoints, with visual function assessments included as efficacy measures. Both conditions involve damage to retinal ganglion cells, the neurons that connect the retina to the brain. Because these cells do not regenerate naturally, their loss results in permanent vision impairment, and existing treatments do not address the underlying neurodegeneration.
The PER platform is built on the delivery of three transcription factors — OCT4, SOX2, and KLF4, collectively referred to as OSK — to aged or damaged cells. The scientific premise is that aging involves progressive, measurable changes to the epigenome that alter gene expression without modifying the underlying DNA sequence. By partially reactivating these factors, the platform is designed to reset epigenetic marks toward a younger state while preserving cell identity. The approach deliberately omits a fourth Yamanaka factor, c-MYC, which carries oncogenic risk and, when included alongside the other three, drives cells toward full dedifferentiation. The OSK combination is intended to occupy a middle ground: sufficient epigenetic reset to restore cellular function, without erasing tissue-specific identity.