AptaTargets has announced an agreement with German pharmaceutical giant Merck—signed in October 2024—for the clinical development and commercialisation of ApTOLL, a Toll-like receptor 4 (TLR4) antagonist being developed to treat acute ischaemic stroke.
“This transaction represented an important step forward for AptaTargets and for the development of ApTOLL,” said David Segarra, co-founder and chief executive officer (CEO) of AptaTargets. “Partnering with Merck […] provides the resources and expertise needed to bring this potentially life-saving therapy to stroke patients worldwide.”
ApTOLL is described by AptaTargets as a first-in-class neuroprotective drug that acts on TLR4 with high specificity, blocking the inflammatory response that occurs after an ischaemic stroke. TLR4 signalling is thought to be central to the innate inflammation induced by acute ischaemic injury, and inhibiting TLR4 aims to down-regulate these neuroinflammatory mechanisms, the company further claims in a recent press release.
In a Phase 1b/2a clinical study published in JAMA Neurology, ApTOLL has demonstrated positive safety and efficacy results for acute ischaemic stroke, including reduced mortality and improved functional recovery. ApTOLL was granted a Priority Medicines (PRIME) designation from the European Medicines Agency (EMA) in 2023.
“Stroke is amongst the most common and disabling neurological conditions where effective treatments are still very limited,” said Jan Klatt, head of development for the neurology and immunology unit in Merck’s healthcare business sector. “ApTOLL’s novel therapeutic approach with encouraging early clinical data is complementary to our internal science targeting TLR biology. We expect the programme to enter Phase 2b in 2026 and potentially become an addition to our neurology portfolio in the future.”
Under the terms of this agreement, Merck has assumed responsibility for the global development and commercialisation of ApTOLL, with AptaTargets providing ongoing transitional support. The transaction included an upfront payment to AptaTargets along with development and commercial milestone payments, and royalties on net sales, the company’s release states.
