Interim analysis concluded planned study numbers combined with participant dropout rates were insufficient to meet primary endpoint.

This Phase 2 study will evaluate the safety and efficacy of monthly intravenous doses of IXT-m200 in treatment-seeking individuals with methamphetamine (METH) use disorder. The hypothesis are that following an initial relapse, IXT-m200 will reduce the occurrence of stimulant-positive saliva samples compared to placebo and improve the signs and symptoms of METH Use Disorder (MUD).

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:

    1. 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
    2. Kidney function tests (creatinine and BUN) <2 times the upper limit of normal;

12. 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;

13. 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;

14. 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;

15. Be pregnant or lactating;

16. 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.

Final datasets are expected to contain IXT-m200 concentrations and immunogenicity results, METH use frequencies, Treatment Effectiveness Assessment scores, and safety data over time. No individually identifiable private information will be distributed.

These datasets will be available for distribution following submission to the FDA of the Clinical Study Report and publication. They will be available for 2 years after the initial publication.

These datasets and associated documentation will be made available on CD by the Sponsor to requestors under a data sharing agreement that provides for: (1) a commitment to using the data only for research purposes; (2) a commitment to securing the data using appropriate computer technology and not distributing to third parties; and (3) a commitment to destroying or returning the data after analyses are completed. Requests should be sent to intervexion@gmail.com.

32 weeks

Early termination due to missing data leading to small numbers of participants analyzed. Participants did not submit drug tests as required.