Slate Medicines emerged from stealth mode with $130 million in Series A financing to advance a novel anti-PACAP antibody for migraine prevention, targeting patients who have not responded adequately to existing treatments. The Raleigh, North Carolina-based startup announced plans to begin Phase 1 clinical testing of its lead drug candidate, SLTE-1009, in mid-2026. The monoclonal antibody is designed to block pituitary adenylate cyclase-activating polypeptide, a protein found throughout the central nervous system that plays a role in migraine progression independent of CGRP.
According to the company’s announcement, SLTE-1009 was engineered with half-life extension technology that enables subcutaneous administration, though specific dosing intervals were not disclosed. The Series A round was led by RA Capital, Forbion, and Foresite Capital, with participation from an undisclosed biotech investor. Additionally, Slate maintains an undisclosed pipeline of drug candidates beyond its lead migraine prevention therapy.
Addressing Unmet Needs in Migraine Treatment
While CGRP inhibitors have transformed migraine care over the past decade, progressing from novel medicines to first-line therapies, a significant patient population remains underserved. These patients experience inadequate responses to CGRP-blocking drugs and other available migraine treatments. PACAP-targeting therapies represent what the company describes as an orthogonal approach to migraine prevention, working through a mechanism distinct from CGRP inhibition.
Research has shown that PACAP activity in migraine occurs independently of CGRP, making it a compelling target for patients who do not benefit from current standard-of-care options. The protein is widely distributed in the central nervous system and has been clinically validated as a target for migraine prevention. However, developing successful anti-PACAP therapies has proven challenging for the pharmaceutical industry.
Competition in the Anti-PACAP Space
Slate enters a field where other companies have pursued PACAP-blocking antibodies with mixed results. Eli Lilly advanced a PACAP38-targeting antibody into mid-stage clinical development but discontinued the program in 2022, according to company documents. Meanwhile, Lundbeck has continued development of bocunebart, formerly known as Lu AG09222, which the company acquired as part of its 2019 purchase of Alder BioPharmaceuticals.
Earlier this month, Lundbeck reported positive preliminary Phase 2b results for intravenous bocunebart in migraine prevention. The company stated the drug demonstrated statistically significant reduction in monthly migraine days compared to placebo, without disclosing specific figures. According to Lundbeck, bocunebart was generally well tolerated with no new safety signals observed in the trial.
A separate group is currently evaluating a subcutaneously injectable formulation of bocunebart. Based on the Phase 2b results, Lundbeck plans to meet with regulatory authorities to discuss Phase 3 study design and intends to present detailed data at an upcoming scientific meeting. In contrast, Slate’s announcement claims SLTE-1009 has the potential to be best-in-class among anti-PACAP antibodies, though the company declined to provide supporting details through a spokeswoman.
Experienced Leadership Team
Slate Medicines is led by CEO Gregory Oakes, who previously served as a venture partner at Raven, RA Capital Management’s healthcare incubator. Before that role, Oakes was president and CEO of Landos Biopharma, which AbbVie acquired in 2024. The company’s Chief Medical Officer, Roger Cady, brings direct experience with PACAP-targeting therapies from his previous roles at Alder BioPharmaceuticals and Lundbeck.
“PACAP blockade represents a clinically validated approach for the prevention of migraine headaches,” Cady said in a prepared statement. “For the millions of patients with an inadequate response to existing standard of care, we believe that SLTE-1009 offers a novel, orthogonal approach to preventing migraines.”
The company expects to initiate Phase 1 testing of SLTE-1009 in mid-2026, though specific trial details and patient enrollment timelines have not been announced. Slate has not disclosed information about other pipeline candidates or additional therapeutic areas under development.