New Headache Drug Targets Beyond CGRP: PACAP, Endocannabinoids, Sex Specific Pathways, and More
| Audience | Patients, clinicians, healthcare providers, researchers, and policy analysts. |
| Primary Topic | Clinical study review: New Headache Drug Targets Beyond CGRP: PACAP, Endo. |
| Source | Read the full source |
New Headache Drug Targets Beyond CGRP: PACAP, Endocannabinoids, Sex Specific Pathways, and More
A 2025 narrative review maps emerging headache therapies beyond CGRP, including PACAP antibodies, endocannabinoid modulation, prolactin, orexin, PAR2, and nitroxidative stress targets.
| Post Type | Physician-Guided Clinical Science Deep Dive |
| Primary Source | Headache |
| Publication Date | 2026Sep28 |
| Evidence Level | Journal Article, Review |
| Focus Area | New Headache Drug Targets Beyond CGRP: PACAP, Endocannabinoi |
| Lead Authors | Adriana Della Pietra, Peter J Goadsby, Carolina Oldoni, Stephen Silberstein et al. |
| DOI | 10.1111/head.70202 |
| PMID | PMID: 42806606 |
Mainstream Media Claim: Migraine treatment is moving beyond CGRP, and new targets such as PACAP and the endocannabinoid system may soon transform headache care.
Primary Journal Data: This is a narrative review, not a new randomized trial or meta-analysis. It summarizes PubMed, Scopus, and clinical trial registry findings, including two phase 2 trials of a PACAP monoclonal antibody showing preventive efficacy in migraine, plus earlier preclinical and clinical development evidence for endocannabinoid, prolactin, orexin 2, PAR2, and peroxynitrite related targets.
Dr. Caplan’s Clinical Verdict: The excitement is justified but uneven. PACAP now has meaningful human trial support, while most other targets remain hypothesis generating, early stage, or mechanistically promising rather than ready for routine clinical prescribing.
Study Overview: This narrative review summarizes novel applications for the use of calcitonin gene-related peptide (CGRP)-targeted therapies that go beyond migraine, the latest updates with respect to targeting pituitary adenylate cyclase-activating peptide (PACAP) as therapeutic in migraine, as well as exploring other more recently discovered targets that are undergoing preclinical through advanced clinical development, for the prevention and treatment of headache disorders. Headache disorders affect over one billion individuals worldwide and represent a major public health burden. Although CGRP-targeted therapies have transformed migraine care, a substantial proportion of patients do not achieve adequate relief or remain untreated. Therefore, there is the need to identify and validate novel mechanistic targets across the full spectrum of headache disorders. This narrative review reports preclinical and clinical evidence for emerging therapeutic targets in headache, with a focus on those presented at the 2025 Scottsdale meeting of the American Headache Society, during the Advanced Science session. Literature searches were performed on specific topic areas using PubMed/Scopus to find relevant peer-reviewed literature, as well as studies in ongoing clinical trial registries. In addition to their established efficacy in migraine, CGRP-targeted therapies are increasingly being explored across other headache disorders, reflecting their broader relevance to headache pathophysiology. Beyond CGRP, several promising targets have emerged. PACAP has been identified as a CGRP-independent headache mediator, supported by robust preclinical data and two phase 2 trials demonstrating preventive efficacy with a PACAP monoclonal antibody in migraine. The endocannabinoid system shows antinociceptive potential, particularly through multitarget modulation of cannabinoid receptors and endocannabinoid-degrading enzymes. Several therapeutic targets in earlier stages of development are also gaining attention. Among these, prolactin signaling and orexin-2 receptor pathways represent sex-specific mechanisms, demonstrating female-specific and male-specific relevance in headache-related nociception, respectively. Additionally, protease-activated receptor-2 is implicated in dural-trigeminovascular nociceptive sensitization and advancing through early clinical development. Finally, modulation of reactive nitroxidative species with peroxynitrite has emerged as an early-stage strategy given its role in trigeminovascular sensitization and central pain maintenance. Altogether, these emerging targets expand the therapeutic landscape for headache disorders beyond CGRP and support a shift toward alternative, sex-informed, and potentially combinatorial approaches for headache prevention and treatment, with the potential to benefit the untreated portion of patients. Calcitonin gene‐related peptide (CGRP)‐targeted drugs have been a major success in migraine treatment and are now being studied for use in other headache disorders, yet many patients still struggle to adequately manage their migraine. Several new treatment targets, which work differently than CGRP, show promise in early research and clinical studies. These findings suggest that expanding beyond CGRP, and developing more personalized or combinatorial treatments, could improve care for people whose headaches remain inadequately treated.
Primary Source & Scope: Published in Headache (2026Sep28) conducted by Adriana Della Pietra, Peter J Goadsby, Carolina Oldoni, Stephen Silberstein et al.. Primary Source Link | Primary Record: DOI: 10.1111/head.70202 | PMID: 42806606
Clinical research into Novel targets in headache: A narrative review. is progressing through rigorously documented peer-reviewed cohorts.
Evaluating primary evidence enables clinicians to tailor care plans while respecting therapeutic boundaries.
From a clinical perspective, Novel targets in headache: A narrative review. underscores the necessity of evaluating primary data rather than commercial headlines.
Clinicians discussing these findings should ground patient recommendations in individualized care, verified formulation standards, and monitored therapeutic outcomes.
How to Interpret This Clinical Study
Navigating biomedical publications regarding Novel targets in headache: A narrative review requires reviewing study methodology and patient eligibility.
Three Rules for Critical Reading
Separate evidence tiers
PACAP has phase 2 human preventive migraine data, while several other targets rely mainly on preclinical or early clinical signals.
Critical Rule
Do not equate endocannabinoid system pharmacology with proven efficacy of dispensary cannabis products for headache prevention.
Critical Rule
Look for future trials that report monthly migraine days, responder rates, acute medication use, disability outcomes, sex stratified results, and long term safety.
CED Perspective Lens: Eight Clinical Viewpoints
Analyzing evidence across clinical, patient, safety, dosing, and physiological perspectives
Clinical Evidence Synthesis
This paper is a narrative review built from PubMed, Scopus, and clinical trial registry searches, with emphasis on targets discussed at the 2025 American Headache Society Scottsdale meeting. Its strongest human signal is PACAP blockade, supported by two phase 2 migraine prevention trials.
The endocannabinoid system, prolactin, orexin 2, PAR2, and peroxynitrite pathways are presented with more mixed maturity. Some have compelling animal models or mechanistic human plausibility, but not yet the replicated phase 3 evidence that changed practice for CGRP therapies.
Patient Communication
Patients who did not respond to triptans, gepants, ditans, or CGRP monoclonal antibodies often feel that treatment failure reflects something personal. This review helps reframe the problem: migraine and headache disorders involve multiple biological systems, not one universal pathway.
The patient conversation should emphasize options without overpromising. Emerging targets may eventually help people with refractory migraine, cluster headache, or other headache disorders, but most are not yet available as approved therapies outside trials. Continuous monitoring of real-world outcomes and transparent communication among stakeholders ensures that clinical practice evolves alongside administrative guidelines.
Dosing & Formulations
The review does not provide prescribing doses for emerging agents because many remain in trial development. PACAP monoclonal antibodies would likely follow biologic style dosing schedules if approved, but final dose, interval, and patient selection require phase 3 confirmation.
For endocannabinoid strategies, this is especially important. The paper discusses modulation of cannabinoid receptors and endocannabinoid degrading enzymes, not a validated cannabis product, THC ratio, CBD dose, or dispensary formulation for headache prevention. Continuous monitoring of real-world outcomes and transparent communication among stakeholders ensures that clinical practice evolves alongside administrative guidelines.
Safety & Side Effect Profile
CGRP therapies have accumulated substantial clinical experience, but newer targets need their own safety record. PACAP, orexin, prolactin, protease signaling, and oxidative pathways participate in normal physiology, so blocking or modifying them could produce unanticipated effects.
For cannabinoid related approaches, safety depends heavily on mechanism. Enzyme inhibition, receptor selective drugs, CBD dominant products, and THC containing cannabis are not interchangeable, especially regarding cognition, driving, anxiety, medication interactions, and misuse risk. Continuous monitoring of real-world outcomes and transparent communication among stakeholders ensures that clinical practice evolves alongside administrative guidelines.
Regulatory & Policy Dynamics
Regulators typically require randomized, adequately powered trials with clinically meaningful endpoints such as monthly migraine days, responder rates, acute medication use, disability scores, and safety follow-up. A narrative review can guide priorities, but it cannot authorize practice changes.
Access will also matter. CGRP therapies improved care but created insurance barriers for many patients. Future PACAP or combination biologics may face similar step therapy, prior authorization, and cost constraints unless evidence clearly identifies who benefits most.
Mechanisms & Physiology
CGRP remains central to migraine biology, but PACAP appears capable of provoking headache through partly independent mechanisms. That distinction matters because it offers a rational path for patients whose attacks persist despite CGRP pathway blockade.
Sex specific mechanisms are another important theme. Prolactin signaling may be more relevant in female headache nociception, while orexin 2 receptor pathways may have male specific relevance in some models, suggesting future trials may need sex stratified designs. Continuous monitoring of real-world outcomes and transparent communication among stakeholders ensures that clinical practice evolves alongside administrative guidelines.
Research Limitations
The article is not a systematic review with pooled effect sizes, formal risk of bias scoring, or a unified evidence grading framework. Because it is narrative, topic selection and interpretation may emphasize promising mechanisms presented at a specialty meeting.
Many targets are supported by preclinical models that do not always predict human benefit. Dural or trigeminovascular sensitization models are useful, but clinical headache disorders include behavior, sleep, hormones, comorbidity, stress, and medication overuse. Continuous monitoring of real-world outcomes and transparent communication among stakeholders ensures that clinical practice evolves alongside administrative guidelines.
Future Outlook
The next wave of headache therapeutics may look less like one blockbuster pathway and more like a menu of biologically matched interventions. PACAP blockade, PAR2 inhibition, oxidative modulation, and endocannabinoid system drugs could eventually fill different clinical niches.
The most important future studies will compare mechanisms, identify biomarkers, stratify by sex, and test combination strategies after CGRP partial response. That approach could move headache care from trial and error toward mechanism guided treatment selection. Continuous monitoring of real-world outcomes and transparent communication among stakeholders ensures that clinical practice evolves alongside administrative guidelines.
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Frequently Asked Questions
Does this review prove that PACAP drugs work for migraine?
It does not prove approval level efficacy, but it reports that two phase 2 trials of a PACAP monoclonal antibody showed preventive benefit in migraine. Phase 3 trials, longer safety follow-up, and regulatory review are still needed.
Is PACAP the same as CGRP?
No. PACAP is a different neuropeptide pathway that may trigger headache through mechanisms partly independent of CGRP. This matters because PACAP blockade could help some patients who have incomplete response to CGRP targeted therapies.
Does this mean CGRP medications are becoming obsolete?
No. CGRP therapies remain among the most important migraine advances in decades. The review argues that additional targets are needed because a substantial proportion of patients still have inadequate relief.
What does the review say about cannabis or cannabinoids for headache?
It discusses the endocannabinoid system as a biologically plausible pain modulating network, especially through cannabinoid receptors and enzymes that degrade endocannabinoids. It does not establish a specific cannabis strain, THC dose, CBD dose, or product as proven headache therapy.
Are these new targets available for patients now?
Most are not available as approved headache treatments. PACAP targeted therapy is the most clinically advanced among the newer options described, while prolactin, orexin 2, PAR2, peroxynitrite, and many endocannabinoid strategies remain investigational.
Why are sex specific headache mechanisms important?
Migraine prevalence, hormonal patterns, and pain signaling can differ by sex. The review highlights prolactin signaling as potentially female relevant and orexin 2 pathways as potentially male relevant, which may influence future trial design and treatment matching.
Could patients combine CGRP and PACAP treatments someday?
That is a plausible future research direction, especially for partial responders, because the pathways may not fully overlap. However, combination treatment would require trials proving added benefit, safety, and cost effectiveness.
What is PAR2, and why does it matter in headache?
Protease activated receptor 2, or PAR2, is involved in dural and trigeminovascular sensitization, processes linked to headache pain amplification. The review describes PAR2 as an emerging target advancing through early clinical development.
What role does oxidative stress play in headache?
The review discusses reactive nitroxidative species, including peroxynitrite, as contributors to trigeminovascular sensitization and central pain maintenance. This is an early stage strategy, not yet a validated clinical treatment approach.
How should patients use this information in a clinic visit?
Patients should ask whether their current diagnosis, attack pattern, medication response, comorbidities, hormones, sleep, and medication overuse have been reassessed. Emerging therapies are promising, but optimizing available evidence based care remains essential.
