A Study for GSK3862995B in Healthy Participants and Participants With Chronic Obstructive Pulmonary Disease

Inclusion Criteria:

Healthy participants (Part A)

• Participant must be 18 to 65 years of age inclusive.

• Participants who are overtly healthy as determined by medical evaluation includingmedical history, physical examination, laboratory tests, and cardiac monitoring

• Body weight within the range 50-110 kilogram (kg) (inclusive)

• Body mass index (BMI) within the range 19.5-32 kilogram per square meter (kg/m^2)

• Male and/or female of non-childbearing potential

Participants with Chronic Obstructive Pulmonary Disorder (COPD) (Part B)

• Participant must be 40 to 75 years of age inclusive.

• Body weight within the range 50-110 kg (inclusive)

• BMI within the range 19.5-32 kg/m^2

• Participant has a confirmed diagnosis of COPD for greater than (>)12 months

• Participants must present with a measured post-salbutamol Forced expiratory volumein 1 second/Forced vital capacity (FEV1/FVC) ratio of less than (<) 0.70 atscreening to confirm the diagnosis of COPD and a measured post-salbutamol FEV1greater than or equal to (>=) 40% of predicted normal values.

• Participants must have a well-documented requirement for optimized standard of carebackground therapy that includes daily inhaled medication.

• A peripheral blood eosinophil count of >=150 cells/microliter (mcL) at screening

• Former cigarette smokers with a history of cigarette smoking of >=10 pack-years atscreening current smokers (includes the use of any type of nicotine containingproduct), or non-smokers are permitted

• Male and/or female of non-childbearing potential.

Exclusion Criteria:

• Participant has a past or current medical condition(s) or disease(s) that is/are notwell controlled and, which in the judgement of the Investigator, may affectparticipant safety or affect study endpoints.

• A history of recurrent infections, or treatment of a chronic infection within 3months prior to the first dose of study drug, including both serious local infection (for example, cellulitis, abscess) or systemic infection (for example, pneumonia,tuberculosis, hepatitis B, shingles).

• Significant allergies to humanized monoclonal antibodies.

• Clinically significant multiple or severe drug allergies, intolerance to topicalcorticosteroids, or severe post-treatment hypersensitivity reactions (including, butnot limited to, erythema multiforme major, linear immunoglobulin A (IgA) dermatosis,toxic epidermal necrolysis, and exfoliative dermatitis).

• Lymphoma, leukemia, or any malignancy within the past 5 years except for basal cellor squamous epithelial carcinomas of the skin that have been resected with noevidence of metastatic disease for 3 years.

• Breast cancer within the past 10 years

• Alanine transaminase (ALT) >1x upper limit of normal (ULN)

• Total bilirubin >1.5xULN (isolated total bilirubin >1.5xULN is acceptable if totalbilirubin is fractionated and direct bilirubin less than (<) 35%).

• Current or chronic history of liver disease or known hepatic or biliaryabnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones).

• A clinically significant abnormality in 12-lead ECG readings performed at screening

• A clinically significant abnormality in the Holter monitor performed at screening (IV cohorts only).