The goal of this clinical trial is to evaluate whether Insulex® R demonstrates similar pharmacokinetic (PK) and pharmacodynamic (PD) profiles compared to Humulin® R after a single subcutaneous dose of 0.3 units/kg in healthy adult volunteers.

This Phase 1, randomized, double-blind, two-period, two-sequence crossover clinical trial aims to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) bioequivalence of Insulex® R compared to Humulin® R after a single subcutaneous dose of 0.3 units/kg in healthy adult subjects. The study was designed in accordance with international regulatory guidelines, including the U.S. Food and Drug Administration (FDA) guidance for demonstrating biosimilarity of insulin products and the European Medicines Agency (EMA) guidelines for the clinical development of biosimilar insulins. Each subject underwent a Screening Visit (Visit 1), two 1-day in-house Treatment Periods (Visit 2 and Visit 3), and a Follow-up Visit (Visit 4) to performed safety procedures. The washout period between Treatment Periods was 7 to 14 days. During each Treatment Period, subjects will receive a single subcutaneous dose of either Insulex® R or Humulin® R under euglycemic glucose clamp conditions. Blood samples will be collected at prespecified intervals to measure serum insulin and C-peptide concentrations. Glucose infusion rates will be monitored continuously to assess PD response. The rigorous assessment of PK and PD profiles under controlled clamp conditions is essential to confirm biosimilarity and ensure therapeutic equivalence. Successful demonstration of bioequivalence will provide a safe, effective, and cost-accessible recombinant human rapid-acting insulin option for patients requiring insulin therapy.

Inclusion Criteria:

1. Healthy female and male adults, ages ≥ 18 and ≤ 55 years
2. Body mass index (BMI) ≥ 18.5 kg/m2 to ≤ 27.0 kg/m2 and stable body weight by history for ≥ 3 months (defined as change < 5%)
3. Fasting plasma glucose < 100 mg/dL and HbA1c < 5.7% (based on American Diabetes Association [ADA] criteria; American Diabetes Association, 2023)
4. Female subjects of childbearing potential (WOCBP) must use highly effective contraception as defined in section 9.1.9 Contraception. For surgically sterile subjects (e.g., those who have undergone bilateral tubal ligation, hysterectomy, bilateral salpingectomy, bilateral oophorectomy), the site will attempt to retrieve medical records that document the sterility; however, the absence of records will not exclude the participant. If medical records cannot be obtained, serum and urine pregnancy tests will be performed. For postmenopausal females (no menses > 12 months), postmenopausal status will be confirmed through testing for FSH levels in the menopausal range (as specified by the responsible laboratory) for amenorrheic subjects.
5. Subjects must be able to provide written informed consent and are willing to follow study procedures and commitment to the study duration.

Exclusion Criteria:

1. Pregnant, lactating or intending to become pregnant during the study.
2. Subjects with confirmed diabetes type 1 or type 2.
3. Presence of any clinically significant co-morbidities, or physical exam, ECG, or laboratory findings at screening or upon clinic admission that, in the opinion of the Investigator, may interfere with any aspect of study conduct or interpretation of the study results.
4. Active or untreated malignancy or has been in remission from clinically significant malignancy (other than basal cell or squamous cell skin cancer, in situ carcinomas of the cervix, or in situ prostate cancer) for < 5 years.
5. Supine heart rate > 100 or < 40 beats per minute at screening, based on the average of 3 consecutive measurements.
6. Supine systolic blood pressure > 140 mm Hg or < 90 mm Hg and/or diastolic blood pressure ≥ 90 mm Hg at Screening or upon clinic admission. If blood pressure is outside of the specified ranges, it may be repeated once 20-30 minutes later the same day.
7. Subjects with a prior history of any serious adverse reaction, hypersensitivity to study drugs or drug components.
8. History of any major surgery within 6 months prior to screening, per Investigator discretion.
9. History of any active infection, other than mild viral illness within 30 days prior to the first dose of study drug as judged by the Investigator.
10. History of any active infection, other than mild viral illness within 30 days prior to the first dose of study drug as judged by the Investigator.
11. History of regular use of nicotine-containing products (including but not limited to cigarettes, e-cigarettes, pipe, chewing tobacco, nicotine patch or gum) or vaping products within 3 months prior to check-in for the first in-house period. Subjects must refrain from using nicotine-containing products until after the completion of the Follow-Up Visit after the last dose of study drug.
12. History of drug abuse as judged by the Investigator or a positive urine drug test at Screening or upon clinic admission. Frequent use of marijuana or other tetrahydrocannabinol (THC) products within 6 weeks, or clinically under the effect at screening or upon clinic admission, as per Investigator evaluation or a positive urine drug test at Screening or upon clinic admission.
13. History of or positive test for hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV Ab), or human immunodeficiency virus type 1 (HIV-1) or type 2 (HIV-2) antibody.
14. Subject is not able to avoid physical activity, avoid alcohol, caffeinated drinks, smoking or medication other than the study medication for 24 hours prior to and throughout the treatment period. (Herbal products and non-routine vitamins are not allowed within 14 days prior to dosing. Routine vitamins are permitted up to 48 hours prior to dosing. Chronic use of acetaminophen is excluded, but occasional use is permitted.) Adequate washout for any concomitant medication that may impact insulin's effect on blood glucose must be ensured and such medications cannot be used throughout the treatment period.
15. Laboratory or clinical evidence of current infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), i.e., COVID-19, at Screening or upon clinic admission or administration of an approved, authorized, or emergency use approved COVID-19 vaccine within 14 days prior to dosing with study drug.
16. Any anticipated/planned procedures (e.g., surgery), that interfere with the compliance or the subject's ability to complete the study.
17. Participation in an investigational study within 30 days prior to dosing or 5 half-lives within the last dose of investigational product whichever is longer.
18. Have previously participated, completed, or withdrawn from this study.
19. Donation or loss of > 500 mL of whole blood within 8 weeks, platelets within 2 weeks and plasma within 4 weeks of the first dose of study drug. Receipt of blood products within 2 months prior to check-in.