A Study to Evaluate Efficacy and Safety of GSK3858279 in Diabetic Peripheral Neuropathic Pain

Inclusion Criteria: * Participant must be 18-75 years of age inclusive, at the time of signing the informed consent. * Type I or Type II diabetes with painful, distal, symmetrical, sensory motor neuropathy attributed to diabetes, of at least 6 months duration. * A pain score ≥4 and less than or equal to (≤) 9 by the 11-point NRS (0-10) for average daily pain intensity over the past 24 hours at the screening visit. * Body mass index (BMI) within the range 18-40 kilogram per meter square (kg/m\^2) (inclusive) * Capable of giving signed informed consent. Exclusion Criteria: * History or presence of cardiovascular, renal, gastrointestinal, lymphatic disorders which in the opinion of the investigator would interfere with the study procedures and/or assessments. * Participant has current painful peripheral neuropathy due to a cause other than diabetes (e.g. pernicious anemia, hypothyroidism, post-herpetic neuralgia). * History of significant allergies to monoclonal antibodies. * Current enrolment or past participation in a clinical study of an investigational medicinal product intervention within the last 30 days or 5 half-lives (whichever is longer) of signing consent. * Participants who are unlikely to comply with the protocol (e.g. uncooperative attitude, inability to return for subsequent visits, inability to complete the eDiary daily etc.) and/or otherwise considered by the Investigator to be unlikely to complete the study.