A Study to Assess Adverse Events and How Single and Multiple Ascending Doses of ABBV-903 Move Through the Body in Healthy Adults

Maximum Observed Plasma Concentration (Cmax)

Cmax will be assessed.

Time frame: Baseline to Day 36

Time to Cmax (Tmax)

Tmax will be assessed.

Time frame: Baseline to Day 36

Apparent Terminal Phase Elimination Constant (β)

Apparent terminal phase elimination constant (β) will be assessed.

Time frame: Baseline to Day 36

Terminal Phase Elimination Half-life (t1/2)

Terminal phase elimination half-life (t1/2) will be assessed.

Time frame: Baseline to Day 36

Area Under the Plasma Concentration-time Curve (AUC)

AUC will be assessed.

Time frame: Baseline to Day 36

Area Under the Plasma Concentration-time Curve from Time 0 Until the Last Measurable Concentration (AUCt)

AUCt will be assessed.

Time frame: Baseline to Day 36

Area Under the Plasma Concentration-time Curve from Time 0 Until Infinity (AUCinf)

AUCinf will be assessed.

Time frame: Baseline to Day 36

Number of Participants with Adverse Events (AEs)

An AE is defined as any untoward medical occurrence in a patient or clinical investigation participant administered a pharmaceutical product which does not necessarily have a causal relationship with this treatment.

Time frame: Baseline to Day 66