A study to assess the safety and processing by the body of GDC-5780 in healthy participants

INTERVENTION: Randomization A Block randomization method is used to generate a master randomization list. The sentinel subjects and remainder subjects are randomized separately, where the sentinel subjects have a 2:1 randomization ratio of GDC‐5780 to placebo with a block size of 3, and the remaining subjects have a 4:1 randomization ratio of GDC‐5780 to placebo with a block size of 5. Participants will need to be a part of this study for about 40 days after the screening. The study will have three parts: ‐ Screening Period: Potential participants will be screened to check if they are eligible to participate in the study. The screening visit will take place up to 28 days before the study starts. ‐ Treatment Period: During this period participants will be required to check in to the clinic 2 days prior to treatment initiation. The participants will have to remain in the clinic for about 18 nights (Day ‐2 up to Day 17). Participants in each cohort will receive GDC‐5780 or a GDC‐5780 matched placebo as intravenous (IV) infusion multiple times per day for 10 days at escalating doses. Based on the safety data and the decision of the safety monitoring committee (SMC), participants may be enrolled in further cohorts to receive GDC‐5780. ‐ Follow‐up visit: Follow‐up visits will be conducted to check on the participants after they complete the treatment. Participants will have to return to the clinic for four follow‐up visits, with the last visit taking place about 28 days after the final dose of the study drug i.e., on Days 20, 24, 31, and 38. Please note, the doses for each cohort are subject to change depending on the pharmacokinetics and/or safety/tolerability of GDC‐5780, an CONDITION: Healthy volunteers ; Not Applicable PRIMARY OUTCOME: ; 1. Incidence and severity of adverse events (AEs), with severity determined according to the Division of AIDS (DAIDS) toxicity grading scale and a modified Common Terminology Criteria for Adverse Events (CTCAE) grading scale for infusion related reactions, measured using data from electronic Case Report Forms (eCRFs) from initiation of the study up to Day 38; 2. Incidence and severity of vital sign, laboratory test, and electrocardiogram (ECG) abnormalities measured using data from vital signs recorded (respiratory rate, pulse rate, systolic and diastolic blood pressure, and temperature), laboratory test results (serum/plasma/urine samples), and ECG readings (single 12‐lead ECG recordings) from initiation of study to 28 days after the last dose (up to Day 38).; INCLUSION CRITERIA: 1. Age 18 ‐ 65 years at time of signing informed consent form (ICF) 2. Body mass inde X(BMI) of = 18.5 and < 30 kilograms per metre squared (kg/m^2) at screening 3. Ability to comply with study protocol SECONDARY OUTCOME: ; 1. Maximum plasma concentration (Cmax) of GDC‐5780 measured using plasma samples collected at multiple timepoints post‐dose on Day 1; 2. Maximum plasma concentration at steady state (Cmax,ss) of GDC‐5780 measured using plasma samples collected at multiple timepoints post‐dose on Day 10; 3. Time to maximum observed concentration (tmax) of GDC‐5780 measured using plasma samples collected at multiple timepoints post‐dose on Day 1; 4. Area under the concentration‐time curve from time 0 to t (AUC0‐ t) of GDC‐5780 measured using plasma samples collected at multiple timepoints post‐dose on Day 1; 5. Area under the concentration‐time curve at steady state (AUC0‐ t,ss) of GDC‐5780 measured using plasma samples collected at multiple timepoints post‐dose on Day 10; 6. Lowest plasma concentration prior to next dose (Ctrough) of GDC‐5780 measured using plasma samples collected prior to first infusion on Days 2‐9; 7. Terminal half‐life (t1/2) of GDC‐5780 measured using plasma samples collected at multiple timepoints post‐dose from Day 10 up to Day 24; 8. Fractional excretion (Fe) of GDC‐5780 measured using pooled urine samples collected at post‐dose timepoints on Day 10; 9. Renal clearance (CLr) of GDC‐5780 measured using pooled urine samples collected at post‐dose timepoints on Day 10;