This Phase 2 trial will evaluate the efficacy and safety of ABP-450 for migraine prevention in adults who suffer from six or more migraine days per month. The study will enroll 765 patients across approximately 64 sites in the United States, Canada and Australia. Study subjects will be divided evenly across a low dose group, a high dose group and a placebo group. All patients will receive two treatment cycles of ABP-450 or placebo utilizing the Company's novel injection paradigm.

The Phase 2 trial will evaluate the efficacy and safety of ABP-450 for migraine prevention in adults who suffer from six or more migraine days per month. The study will enroll 765 patients across approximately 64 sites in the United States, Canada and Australia. Study subjects will be divided evenly across a low dose of ABP-450 group, a high dose of ABP-450 group, and a placebo group. All patients will receive two treatment cycles utilizing the Company's novel treatment paradigm involving fewer injections than the current botulinum toxin treatment option for chronic migraine.

Inclusion Criteria:

1. Patient can understand the ICF, provides signed ICF and patient privacy information (eg, Authorization for Use and Release of Health and Research Study Information) before initiating any study-specific procedure, and agrees to comply with protocol requirements.
2. Male or female patients 18 years or older of age (no upper age limit) at the time of signing the informed consent.
3. Patient has at least a 1-year history of episodic migraine (with or without aura) or chronic migraine (with or without aura) according to the ICHD-3 (2018) definition and diagnostic criteria.
4. Age of the patient at the time of migraine onset <50 years.
5. History of, on average ≥6 migraine or probable migraine days per month in the 3 months prior to Screening.
6. Patient is on a stable dose of medications, if any, as recommended by the patient's health care practitioner, used for acute treatment of migraine for at least 3 months prior to Screening. Patient is not taking any migraine prophylactic treatment prohibited per protocol or if on prophylactic treatment has washed out.
7. A Woman of Child Bearing Potential (WOCBP) must be willing and able to use a medically acceptable and effective method of birth control as determined by the investigator, during the entire study.
8. A WOCBP must have a negative pregnancy test at Screening.
9. Patient is able to read, understand, and complete the eDiary.
10. Patient is willing and able to adhere to the study assessments, visit schedules, and prohibitions, as described in this protocol.

Exclusion Criteria:

Medical Conditions

1. History of migraine accompanied by diplopia or decreased level of consciousness, or retinal migraine.

2. Current diagnosis of chronic tension-type headache, new persistent daily headache, trigeminal autonomic cephalgia (eg, cluster headache), or cranial neuropathy.

3. Confounding and clinically significant pain syndromes (eg, fibromyalgia, chronic low back pain, complex regional pain syndromes) as evaluated by the investigator.

4. Diagnosis of myasthenia gravis, Lambert-Eaton syndrome, amyotrophic lateral sclerosis, or any other significant neuromuscular disease that might interfere with the study.

5. Psychiatric conditions that are uncontrolled and/or untreated, including conditions that are not controlled for a minimum of 6 months prior to Screening as evaluated by the investigator. Patients with a lifetime history of psychosis, mania, or dementia are excluded.

6. History of addiction, including alcohol or drugs of abuse, within 6 months prior to Screening.

7. Hepatitis B (HBsAg positive) or hepatitis C (ie, detectable HCV RNA) virus infection.

   Note: Patients with a prior history of treated hepatitis B virus infection who are antigen negative or patients with a prior history of treated HCV infection who are HCV RNA undetectable may be considered after consultation with the study medical monitor.

8. Any infection or clinically significant skin problem in any of the injection sites.

9. Have been injected with anesthesia or steroids in the targeted muscles during the 30 days immediately prior to initiation of the Baseline period.

10. Any medical condition (including but not limited to viral or other active infections) that, in the opinion of the investigator, classifies the patient as unsuitable for participation in the study or patients who do not seem to be in good general health at the time of Screening, and prior to any investigational study drug administration.

    Note: Patients will not routinely be tested for COVID-19 during the study. Patients presenting with fever or who are symptomatic for COVID-19 will be required to be tested and treated through their general practitioner.

    Other Diagnostic Assessments

11. Significant risk of self-harm based on clinical interview and responses on the C-SSRS, or of harm to others in the opinion of the investigator; patients must be excluded if they report suicidal ideation with intent, with or without a plan (ie, Type 4 or 5 on the C-SSRS) in the past 6 months or report suicidal behavior in the past 6 months prior to Screening.

12. Body mass index ≥38 kg/m2 at Screening.

    Prior/Concomitant Medications and Treatments

13. Use of opioids or barbiturates >2 days per month in the 3 months prior to Screening.

14. Use of CBD or other types of cannabinoids in the 3 months prior to Screening and throughout the study.

15. Any use of botulinum toxin for migraine or any other medical reasons within 4 months prior to Screening and during the Screening and Baseline periods and at or above the shoulders at any time during the study.

16. Any monoclonal antibody CGRP inhibitor treatment (within or outside of a clinical study) within 6 months prior to Screening and throughout the study.

17. Any orally administered non-peptide CGRP antagonists (within or outside of a clinical study) within 4 weeks prior to the Baseline period and throughout the study.

18. Use of devices for the treatment of migraine (ie, non-invasive neuromodulation therapies including but not limited to non-invasive nerve stimulation [gammaCore], transcranial magnetic stimulation [Cefaly], external trigeminal nerve stimulation, transcutaneous electrical nerve stimulation, and peripheral neuroelectrical stimulation) during Screening and throughout the study.

19. Any other treatments or therapies (eg, acupuncture in head and neck region, cranial traction, nociceptive trigeminal inhibition, occipital nerve block treatments, and dental splints for headache) to the head, neck, or shoulder regions during Screening and throughout the study that, in the opinion of the investigator, would interfere with the investigational study drug.

20. History of inadequate response to 3 classes of medications (which have different mechanisms of action) prescribed for the prevention of migraine, excluding CGRP therapies.

21. History of hypersensitivity to human serum albumin, sucrose, or botulinum toxin type A or a positive test for botulinum toxin type A antibody.

    Prior/Concurrent Clinical Study Experience

22. Participation in another interventional study within 6 months prior to Screening and throughout the study.

23. Female patients planning on becoming pregnant during the course of the study and/or lactating/breastfeeding.

24. Patient has donated or lost a significant volume (>450 mL) of blood or plasma within 30 days of screening.

25. Patient is an employee or family member of the investigator, study site personnel, PPD, or AEON.

Individual Participant Data collected during the trial, after deidentification may be shared following review of the clinical study report by the FDA review division and if a decision is made to publish the results in an publication outside posting the results in clinicaltrials.gov

The investigator, study nurse/other study personnel, and patients will be blinded to the treatment group. An appropriately trained person will reconstitute investigational product, fill masked-labeled syringes and provide them to the investigator, but will not perform any assessments with the patient.