Multiple-Dose Study to Evaluate the Safety and Efficacy of IXT-m200

Eligible participants will:

1. Be at least 18 years of age at the time of study consent;
2. Meet Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria for Substance Use Disorder associated with methamphetamine;
3. Be treatment-seeking methamphetamine users with at least 1 methamphetamine or amphetamine positive specimen during the screening period;
4. Be able and willing to read, comprehend, and give Authorization for Use/Disclosure of Health Information (HIPAA) and informed consent;
5. Be willing to comply with study instructions and dosing, agree to make all appointments, and complete the entire course of the study;
6. Agree to use protocol-specified method(s) of birth control throughout study participation;
7. Agree to adhere to Lifestyle Considerations throughout study duration;
8. Have access to a smartphone or other device capable of supporting the study app;
9. Successfully complete app-based training program as evidenced by completion of at least 75% of daily drug use surveys and assigned saliva drug screens (two of which must be valid) in ≤30 days from the screening visit during the screening period.

Eligible participants will NOT:

1. Have current dependence, defined by DSM-5 criteria, on any psychoactive substance (i.e., opioids or benzodiazepines), other than methamphetamine or nicotine (any severity). Mild severity dependence on alcohol or marijuana is allowed;
2. Be currently taking certain other drugs and medications, including: "designer drugs" (e.g., 3,4-methylenedioxyMETH (MDMA, Ecstasy, Adam, XTC) and its N-dimethyl metabolite methylenedioxyamphetamine (MDA), anti-orexigenic drugs (including over-the-counter medications for weight loss), or be chronic users of phenethylamine compounds (e.g., phenylpropanolamine, ephedrine, pseudoephedrine, amphetamine, phentermine, phenmetrazine, methylphenidate, diethylpropion, and propylhexedrine);
3. Have a known contraindication or sensitivity to IXT-m200 based on known allergies to other monoclonal antibodies, any inactive ingredient of IXT-m200, or any other products required for the study procedures;
4. Have a history of severe allergy (rash, hives, breathing difficulty, etc) to any medications;
5. Have a history of allergic or environmental bronchial asthma within the past 3 years;
6. Have a current diagnosis of anorexia nervosa or bulimia disorder;
7. Have a history of unstable cardiovascular disease that is not adequately controlled at the time of eligibility determination;
8. Be mandated by the court to obtain treatment for methamphetamine-dependence where such mandate required the results of methamphetamine testing to be reported to the court;
9. Have positive saliva drug screens for psychoactive substances other than amphetamines at the screening visit;
10. Be expected to fail to complete the study protocol due to probable incarceration or relocation from the clinic area, or any clinically significant mental or physical illness within a 1-year prior, that would impact compliance with trial requirements;
11. Have clinically significant laboratory values (outside of normal limits). The following specified ranges are allowable:
12. Liver function tests (total, direct, and indirect bilirubin, aspartate transaminase, alanine aminotransferase, gamma-glutamyl transferase, lactate dehydrogenase, and alkaline phosphatase) <3 times the upper limit of normal, and
13. Kidney function tests (creatinine and BUN) <2 times the upper limit of normal;
14. Be considered to be at imminent risk of suicide or have a past-year history of a serious suicide attempt (defined as an attempt that results in or requires medical treatment) based on response to queries within eligibility screening about suicidal ideation and attempts;
15. Have an uncontrolled systemic disease or a medical condition that may increase the risk associated with study participation or administration of study treatment or that may interfere with the interpretation of study results;
16. Be currently participating or has participated within the last 30 days prior to the start of this study in a drug, device, or other interventional research study;
17. Be pregnant or lactating;
18. In the Investigator's or Sponsor's (or designee) opinion, be inappropriate for the study, including those believed to be attempting to enter the study primarily for financial gain.