The CRR was defined as the percentage of participants who had a complete response (CR) as the best overall response (BOR) as per Investigator assessment (Lugano response criteria 2014). The BOR was defined as the BOR observed from the date of first study treatment until PD, death, cut-off date or initiation of subsequent anti-cancer therapy, whichever occurred first. CR based on computed tomography (CT)-based response: lymph nodes and extralymphatic sites with target nodes/nodal masses must regress to <=1.5 centimeter (cm) in longest transverse diameter of a lesion (LDi) and no extralymphatic sites of disease.

The efficacy population consisted of all participants from the exposed population with at least one evaluable post-baseline tumor assessment or who permanently discontinued study treatment.

ORR was defined as the percentage of the participants with CR or partial response (PR) as the BOR as per Investigator assessment (Lugano response criteria 2014). The BOR was defined as the BOR observed from the date of first study treatment until PD, death, cut-off date or initiation of subsequent anti-cancer therapy, whichever occurs first. CR (CT-based response): lymph nodes and extralymphatic sites with target nodes/nodal masses must regress to <=1.5cm in LDi and no extralymphatic sites of disease. PR (CT-based response): lymph nodes and extralymphatic sites with >=50% decrease in sum of the product of the perpendicular diameters for multiple lesions (SPD) of upto 6 target measurable nodes and extranodal sites. A lesion too small to measure on CT, 5 millimeter (mm) X 5mm used as default value. No longer visible, 0 X 0 mm. A node >5mm X 5mm, but smaller than normal, actual measurement used.

The efficacy population consisted of all participants from the exposed population with at least one evaluable post-baseline tumor assessment or who permanently discontinued study treatment.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. An SAE was any AE that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect or was an important medical event. TEAEs were defined as AEs that developed, worsened (according to the Investigator's opinion) or became serious during the TE period.

The exposed population consisted of all participants who had given their informed consent and received at least one dose of study treatment.

Selected events that occurred during the DLT observation period were considered as DLT unless due to PD or to a cause obviously unrelated to pegenzileukin. Selected events included: grade 4 neutropenic fever, grade 4 thrombocytopenia associated with clinically significant bleeding that required clinical intervention, grade 3 or above alanine aminotransferase or aspartate aminotransferase in combination with a bilirubin >2 × upper limit of normal with no evidence of cholestasis or another cause, such as viral infection or other drugs, grade 3 or above vascular leak syndrome, grade 3 or above hypotension, grade 3 or above cytokine release syndrome, grade 3 or above AE that did not resolve to grade <=2 within 7 days of starting accepted standard of care medical management.

DLT-evaluable population consisted of all exposed participants in safety run-in part who had been treated and observed for DLT observation period. Any participants who had experienced a DLT during DLT observation period were also DLT-evaluable.

The TTR was defined as the time from the first administration of study treatment to the first tumor assessment at which the overall response was recorded as PR or CR determined by Investigator (Lugano response criteria 2014). CR (CT-based response): lymph nodes and extralymphatic sites with target nodes/nodal masses must regress to <=1.5cm in LDi and no extralymphatic sites of disease. PR (CT-based response): lymph nodes and extralymphatic sites with >=50% decrease in sum of the product of the perpendicular diameters for multiple lesions (SPD) of upto 6 target measurable nodes and extranodal sites. A lesion too small to measure on CT, 5 millimeter (mm) X 5mm used as default value. No longer visible, 0 X 0 mm. A node >5mm X 5mm, but smaller than normal, actual measurement used.

The efficacy population consisted of all participants from the exposed population with at least one evaluable post-baseline tumor assessment or who permanently discontinued study treatment. Only participants with confirmed CR or PR were analyzed.

The DoR was defined as the time from the first tumor assessment at which the overall response was recorded as PR or CR until PD determined by Investigator (Lugano response criteria 2014), or death from any cause, whichever occurred first. CR (CT-based response): lymph nodes and extralymphatic sites with target nodes/nodal masses must regress to <=1.5cm in LDi and no extralymphatic sites of disease. PR (CT-based response): lymph nodes and extralymphatic sites with >=50% decrease in sum of the product of the perpendicular diameters for multiple lesions (SPD) of upto 6 target measurable nodes and extranodal sites. A lesion too small to measure on CT, 5 millimeter (mm) X 5mm used as default value. No longer visible, 0 X 0 mm. A node >5mm X 5mm, but smaller than normal, actual measurement used.

The efficacy population consisted of all participants from the exposed population with at least one evaluable post-baseline tumor assessment or who permanently discontinued study treatment. Only participants with confirmed CR or PR were analyzed.

CBR was defined as percentage of participants with clinical benefit (CR or PR as BOR, or stable disease [SD] lasting at least 6 months) determined by Investigator per Lugano response criteria 2014. BOR was defined as BOR observed from date of first study treatment until PD, death, cut-off date or initiation of subsequent anti-cancer therapy, whichever occurred first. CR (CT-based response): lymph nodes and extralymphatic sites with target nodes/nodal masses must regress to <=1.5cm in LDi and no extralymphatic sites of disease. PR (CT-based response): lymph nodes and extralymphatic sites with >=50% decrease in SPD of upto 6 target measurable nodes and extranodal sites. A lesion too small to measure on CT, 5mm X 5mm used as default value. No longer visible, 0 X 0 mm. A node >5mm X 5mm, but smaller than normal, actual measurement used. SD (CT-based response): <50% decrease from baseline in SPD of up to 6 dominant, measurable nodes and extranodal sites; no criteria for PD met.

The efficacy population consisted of all participants from the exposed population with at least one evaluable post-baseline tumor assessment or who permanently discontinued study treatment.

The PFS was defined as the time from the date of first study treatment administration to the date of the first documented PD determined by Investigator (Lugano response criteria 2014), or death due to any cause. PFS (CT-based response): An individual node/lesion had to be abnormal with: LDi >1.5 cm and increased by >=50% from positron emission tomography nadir and an increase in LDi or shortest axis perpendicular to the LDi from nadir, 0.5cm for lesions <=2 cm, 1.0cm for lesions>2 cm. In the setting of splenomegaly, the splenic length must be increased by >50% of the extent of its prior increase beyond baseline. If there was no prior splenomegaly, increase by at least 2 cm from baseline. For new lesions regrowth of previously resolved lesions: a new node >1.5 cm in any axis, a new extranodal site>1.0 cm in any axis.

The efficacy population consisted of all participants from the exposed population with at least one evaluable post-baseline tumor assessment or who permanently discontinued study treatment.

Blood samples were collected at specified timepoints for the assessment of plasma concentrations of pegenzileukin .

The pharmacokinetic (PK) population consisted of all participants from the exposed population with at least one PK concentration available after the first dose of study treatment. Only participants with data collected at specified timepoints are reported.

Blood samples were collected at specified timepoints for the assessment of Ceoi of pegenzileukin .

The PK population consisted of all participants from the exposed population with at least one PK concentration available after the first dose of study treatment. Only participants with data collected at specified timepoints are reported.

Blood samples were collected at specified timepoints to assess the presence of ADA against pegenzileukin . Treatment-emergent ADA was defined as at least one treatment-induced or treatment-boosted ADA. Treatment-induced ADA was defined as ADA that developed during the TE period and without pre-existing ADA (including participants without pre-treatment samples). Treatment-boosted ADA was defined as pre-existing ADA that was boosted during the TE period to a significant higher titer than the baseline. Number of participants with treatment-emergent ADA is presented.

ADA population consisted of all participants from exposed population with at least one ADA result (positive, negative or inconclusive) after the first dose of study treatment.