An AE is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. A serious adverse event (SAE) is defined as any untoward medical occurrence, whether associated with study drug or not, that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect, or is an important medical event requiring medical or surgical intervention to prevent serious outcome.

A DLT is defined as any AE for which a clear alternative cause cannot be established (eg, attributed to the disease under study, another disease, or to a concomitant medication by the study investigators or medical monitor).

TLS is confirmed by evaluation of electrolyte and fluid status and renal status including urine output.

Clinical laboratory parameters included tests of hematology, chemistry, urinalysis and prolactin. The investigator will assess the results for clinical significance.

Vital sign parameters included body temperature, systolic and diastolic blood pressure, pulse rate, and respiratory rate. The investigator will assess the results for clinical significance.

A standard 12-lead ECG will be performed. The investigator will assess the results for clinical significance.

Maximum observed plasma concentration of ABBV-525.

Time to Cmax of ABBV-525.

Area under the plasma concentration-time curve of ABBV-525.