The primary purpose of this study is to evaluate the safety and efficacy of medical cannabis aerosol containing 0.25, 0.50, 1.0 milligrams (mg) delta (Δ) 9-tetrahydrocannabinol (THC) inhaled three times a day (TID) compared to placebo via the Fixed-dose Syqe Inhaler on pain intensity at Week 15.

This study will assess the efficacy, safety, tolerability, and pharmacokinetics (PK) of medical cannabis aerosol inhaled via the Syqe Inhaler at nominal doses of 0 (placebo), 0.25, 0.5, and 1.0 mg TID of Δ9-THC added on to standard of care for treatment of DPNP.

The target sample size is 192 eligible participants worldwide, randomized from up to approximately 51 recruiting sites in up to approximately 8 countries.

The study consists of 1) a screening period of up to 14 days; 2) a 15-week, parallel-group, randomized, double-blind treatment period, including a 3-week up-titration period and a 12-week maintenance period; and 3) a post-treatment, safety follow-up period of 4 weeks.

Inclusion Criteria:

1. Able to comprehend and willing to sign the informed consent form (ICF), and willing to abide by the study restrictions.
2. Males and females aged between 18 (included) and 75 (included) years.
3. Agree to use only medical cannabis provided by study team until the end of study (EOS) and not to use any other cannabis or cannabis-containing products.
4. Agree not to participate in other interventional clinical studies during participation in this study.
5. Treated with standard of care for DPNP, defined as either duloxetine, gabapentin or pregabalin as monotherapy or a combination of 2, or participants who discontinued the use of standard of care, or amitriptyline used for the management of pain related to DPNP, at least 3 months prior to screening.
6. Confirmed diagnosis of diabetes mellitus type I or type II with stable disease.
7. Glycated hemoglobin (HbA1c) less than or equal to (<=) 10% at screening.
8. Body mass index between 18 and 40 kilograms per square meter (kg/m^2), inclusive.
9. Have at least 5 out of 7 records of daily average pain intensity recordings in the 7 days prior to randomization.
10. Female participants must have a negative serum pregnancy test at screening and a negative urine pregnancy test prior to the administration of study treatment on Day 1or be of non-child-bearing potential as defined in the protocol.
11. Participants of reproductive potential who are sexually active must use highly effective birth control methods.

Exclusion Criteria:

1. Evidence of significant uncontrolled concomitant disease that could affect compliance with the protocol at screening or randomization, ability to complete the study, or study assessments.

2. Presence of skin conditions in the affected dermatome at screening or randomization that could interfere with the evaluation of the neuropathic pain condition.

3. Presence of pain not associated with diabetic peripheral neuropathy (DPN) or other neuropathies that may interfere with study assessments.

4. Known history of significant hypersensitivity, intolerance, adverse reaction or allergy to cannabis products, cannabinoids, or acetaminophen/paracetamol.

5. Malignancies in the past 5 years prior to screening, except for cutaneous basal cell or squamous cell carcinoma resolved by excision.

6. Liver disease or liver injury as indicated by abnormal liver function tests at screening.

7. History or presence of impaired renal function at screening

8. Presence of significant pulmonary disease at screening

9. Ongoing respiratory infection.

10. History of acute coronary syndrome in the last 12 months; unstable angina; congestive heart failure; cardiogenic syncope; cardiomyopathy; or symptomatic arrhythmia, or current uncontrolled blood pressure.

11. Concomitant clinically significant cardiac arrhythmias, examples, sustained ventricular tachycardia, and second or third degree atrioventricular block without a pacemaker, or any other relevant cardiac disease in the judgment of the investigator.

12. History of clinically significant electrocardiograms (ECG) abnormalities, or any of the following ECG abnormalities at screening or baseline:

    • PR greater than (>) 200 milliseconds (msec)
    • QRS complex >120 msec
    • Fridericia QT correction formula (QTcF) greater than (>) 450 msec
    • History of familial long QT syndrome or known family history of ventricular arrythmia.
    • Acute ischemic changes.

13. History or presence of mental illness evidenced as defined in the protocol.

14. Abnormal neurological condition or abnormal neurological examination other than related to DPN as judged by the investigator at screening that impacts the assessment of study endpoints.