A Study of IMB-101 in Healthy Volunteers and Participants With Rheumatoid Arthritis

The primary purpose of this study is to evaluate the safety and tolerability of intravenous (IV) doses of IMB-101 in healthy volunteers and participants with active RA on a stable regimen of methotrexate.


Eligibility Criteria:
Key Inclusion Criteria:

Phase 1a: Healthy Participants:

1. The participant is 18 to 55 years of age, inclusive, at screening.
2. The participant has a BMI of 18.5 to 32 kilogram per square meter (kg/m\^2), inclusive, at screening.
3. The participant is considered by the investigator to be in good general health as determined by medical history, clinical laboratory test results, vital sign measurements, 12-lead ECG results, and physical examination findings to be not clinically significant at screening.
4. Female participants of childbearing potential must use at least 1 form of highly effective methods of birth control from screening until at least 90 days after last study drug dose; OR be surgically sterile OR be postmenopausal. All female participants of childbearing potential must have a negative pregnancy test at screening and before the first dose of study drug. Female participants must also agree to refrain from egg donation during the study and for at least 90 days after study drug dosing.
5. Male participants must agree to use a condom when sexually active with a female partner of childbearing potential during the study and for at least 90 days after study drug dosing (OR be surgically sterile; OR agree to practice abstinence during the study and for at least 90 days after study drug dosing).
6. The participant agrees to comply with all protocol requirements.
7. The participant is able to provide written informed consent.

Phase 1b: Active RA Participant:

1. The participant is 18 to 65 years of age, inclusive, at screening.
2. The participant has a BMI of 18.5 to 35 kg/m\^2, inclusive, at screening.
3. The participant must have a diagnosis of RA based on the 2010 ACR per EULAR criteria for more than 6 months.
4. The participants must have moderate to severe RA characterized as tenderness or pain in at least 6/68 joints with movement and swelling in at least 4/66 joints at screening and baseline.
5. The participants must be on a stable dose of MTX (up to 25 mg per week) for 4 weeks prior to the first dose of study drug and must be able to continue on this stable dose for the duration of the study. Participant must be on a stable, \>=5 mg/week dose of oral folic/folinic acid for at least 4 weeks immediately before Day 1.
6. Systemic corticosteroids (\<=10 mg/day prednisone equivalent) and NSAIDs are permitted if on a stable dose for at least 4 weeks prior to the first dose of study drug and the participant must be stable for the duration of the study.
7. Female participants of childbearing potential must use at least 1 form of highly effective methods of birth control from screening until at least 90 days after study drug dosing; OR be surgically sterile; OR be postmenopausal. All female participants of childbearing potential must have a negative pregnancy test at screening and before the first dose of study drug.
8. Male participants must agree to use a condom when sexually active with a female partner of childbearing potential during the study and for at least 90 days after study drug dosing (OR be surgically sterile; OR agree to practice abstinence during the study and for at least 90 days after study drug dosing).
9. The participant agrees to comply with all protocol requirements.
10. The participant is able to provide written informed consent.

Key Exclusion Criteria:

Phase 1a: Healthy Participants:

1. The participant has any significant acute or chronic medical illness that, in the opinion of the investigator, would impact the participant's ability to complete all study requirements or that might impact the assessment of study data; or the participant has had a clinically significant illness within 30 days prior to study drug dosing per investigator discretion.
2. The participant has a positive COVID-19 molecular diagnostic test result at screening or prior to study drug dosing; or the participant has known or suspected current sequelae from a prior episode of COVID-19.
3. The participant has had major surgery, as determined by the investigator, within 12 weeks prior to study drug dosing.
4. The participant has any of the following prior to study drug dosing:

   • Systolic blood pressure \>140 mmHg and/or diastolic blood pressure \>90 mmHg.
5. The participant has any of the following on 12-lead ECG prior to study drug dosing, confirmed by repeat:

   * Heart rate \<40 or \>100 beats per minute.
   * PR interval \>220 milliseconds (ms).
   * QRS width \>120 ms.
   * QTcF \>=450 ms (male) or \>=470 ms (female).
6. The participant has any of the following clinical laboratory results at screening, confirmed by repeat:

   * WBCs, lymphocytes, or neutrophil counts outside site acceptable ranges per site SOPs.
   * Calculated creatinine clearance \<60 mL (the CKD-EPI formula)
   * ALT or AST \>2\*ULN
   * Total bilirubin \>2\*ULN
7. The participant has a positive test result for HBsAg, anti-HBcAb, hepatitis C virus antibody, or HIV types 1 or 2 antibodies at screening.
8. The participant has a history of TB, active TB, or a positive Quantiferon-TB Gold Plus (QFT-Plus) test at screening.
9. The participant has received any vaccine or used any prescription or over the-counter medications (except acetaminophen \[up to 2 g per day\]), including herbal or nutritional supplements, within 14 days prior to study drug dosing.
10. The participant has received biologic agents within the 3 months prior to study drug dosing, or 5 half-lives, whichever is greater. Participants with a prior history of anti-TNFα exposure will be excluded.
11. The participant is a smoker or has regularly used nicotine or nicotine-containing products within 3 months prior to study drug dosing.
12. History of drug abuse within 1 year prior to screening.
13. The participant has a positive test result for drugs of abuse, alcohol, or cotinine (indicating active current smoking) at screening or prior to study drug dosing.
14. The participant has donated blood or blood products \>500 mL within 30 days prior to study drug dosing.
15. The participant has a history of hypersensitivity to vaccines, the study drug, or to drugs of similar chemical classes including allergy to drug or its excipients.
16. Any reason which, in the opinion of the Investigator, would prevent the participant from participating in the study.

Phase 1b: Active RA Participant:

1. The participant having RA functional status class IV according to the ACR 1991 revised criteria.
2. The participant diagnosed with any other inflammatory arthritis or systemic inflammatory disease (eg, gout, psoriatic or reactive arthritis, Crohn's disease, Lyme disease, juvenile idiopathic arthritis, or systemic lupus erythematosus). Secondary Sjogren's syndrome is not exclusionary.
3. The participant received treatment with any oral DMARDs other than MTX within 4 weeks prior to baseline. Leflunomide should be discontinued at least 8 weeks prior to baseline.
4. The participant has used anti-TNF or other biologic DMARDs in the 3 months prior to baseline (or 5 half-lives, whichever is longer).
5. The participant has adalimumab drug levels or NAbs to adalimumab or detected at screening.
6. The participant received any intra-articular injection therapy for treatment of acute RA flare within 4 weeks before baseline.
7. The participant received IV steroids, immunosuppressants, investigational drugs, and oral anticoagulant or antiplatelet drugs within 4 weeks prior to randomization.
8. The participant has received previous treatment with a B cell-depleting biologic agent or any other immunomodulatory biologic agent within 5 half-lives.
9. The participant has received prior treatment with cyclophosphamide.
10. The participant requires chronic treatment with opioid analgesics within 4 weeks prior to baseline.
11. The participant has received concomitant medication with a half-life \>24 hours within 4 weeks prior to baseline (or 10 half-lives, whichever is longer).
12. The participant is a smoker or has regularly used nicotine or nicotine-containing products within 3 months prior to study drug dosing.
13. The participant has a positive test result for drugs of abuse, alcohol, or cotinine (indicating active current smoking) at screening or prior to study drug dosing.
14. The participant with active TB or a history of TB, or a positive Quantiferon-TB Gold Plus (QFT-Plus) test at screening.
15. The participant has a history and/or current presence of a clinically significant atopic allergy, hypersensitivity, or allergic reactions, also including known or suspected clinically relevant drug hypersensitivity to any components of the test and reference investigational product formulation or comparable drugs.
16. The participant has a history of any infection requiring hospitalization, IV antibiotics, or as otherwise judged clinically significant, within the 3 months prior to screening, or an opportunistic infection within the past 12 months.
17. The participant has a history of malignancy.
18. The participant has a history of NYHA Class III or IV heart failure.
19. The participant has any of the following prior to study drug dosing, confirmed by repeat:

    • Systolic blood pressure \>140 mmHg and/or diastolic blood pressure \>90 mmHg.
20. The participant has any of the following on 12-lead ECG prior to study drug dosing, confirmed by repeat:

    * Heart rate \<40 or \>100 beats per minute.
    * PR interval \>220 ms.
    * QRS width \>120 ms.
    * QTcF \>=450 ms (male) or \>=470 ms (female).
21. The participant has any of the following clinical laboratory results at screening, confirmed by repeat:

    * WBCs, lymphocytes, or neutrophil counts outside the site acceptable ranges per site SOPs.
    * Calculated creatinine clearance \<60 mL (the CKD-EPI formula).
    * ALT or AST \>2\*ULN.
    * Total bilirubin \>2\*ULN.