Laboratory test results are graded using the Common Terminology Criteria for Adverse Events (CTCAE), Version 3.0.

Grade 3 = Severe or medically significant but not immediately life-threatening. Grade 4 = Life-threatening or disabling.

All treated participants. Only participants available at timepoint were included in the analysis.

Adverse events are any unfavorable or unintended signs, symptoms, or diseases occurring in study participants during a clinical trial, regardless of whether they are related to the intervention. They include all-cause mortality, serious adverse events, and other events exceeding a set frequency threshold. Serious adverse events are a subset that result in significant outcomes such as death, life-threatening conditions, hospitalization or its prolongation, persistent or significant disability/incapacity, or other medically important conditions.

All treated participants

Dose-Limiting Toxicities (DLTs) are treatment-related adverse events occurring during the first cycle (typically Days 1-28) that meet predefined severity criteria per NCI CTCAE v4.03. Hematologic DLTs include Grade 4 neutropenia >5 days, Grade 3 neutropenia with fever, Grade 4 thrombocytopenia or Grade 3 with bleeding, and Grade 4 anemia. Non-hematologic DLTs include any toxicity ≥Grade 3 (except alopecia or controlled nausea) or treatment interruption ≥2 weeks due to adverse events.

All Dose Limiting Toxicities evaluable population included in the analysis. Pre-specified to be collected for only Part 1A and 1B.

Objective Response Rate (ORR) is the percentage of participants whose best overall response is Complete Response (CR) or Partial Response (PR) per RECIST v1.1. CR is the disappearance of all target lesions and reduction of pathological lymph nodes to <10 mm. PR is at least a 30% decrease in the sum of diameters of target lesions from baseline. ORR is calculated as: (Number of participants with CR or PR ÷ Total participants) × 100. Confidence intervals are typically estimated using the Clopper-Pearson method.

All treated participants. Part 1A was for dose finding and to assess initial safety. The efficacy analysis was pre-defined to be analyzed on combined arms in Part 1A.

Disease Control Rate (DCR) is the percentage of participants whose Best Overall Response (BOR) is Complete Response (CR), Partial Response (PR), or Stable Disease (SD) per RECIST v1.1. CR is the disappearance of all target lesions and reduction of any pathological lymph nodes to <10 mm. PR is at least a 30% decrease in the sum of diameters of target lesions from baseline. SD is neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for Progressive Disease, taking as reference the smallest sum diameters while on study. DCR is calculated as: (Number of participants with CR, PR, or SD ÷ Total participants) × 100.

All treated participants. Part 1A was for dose finding and to assess initial safety. The efficacy analysis was pre-defined to be analyzed on combined arms in Part 1A.

Duration of Response (mDOR) is the median time from the first documented occurrence of Complete Response (CR) or Partial Response (PR) until disease progression or death, assessed per RECIST v1.1. CR is the disappearance of all target lesions and reduction of pathological lymph nodes to <10 mm. PR is at least a 30% decrease in the sum of diameters of target lesions from baseline. Progression is defined as at least a 20% increase in the sum of diameters of target lesions or appearance of new lesions.

All treated participants with response (CR or PR). Part 1A was for dose finding and to assess initial safety. The efficacy analysis was pre-defined to be analyzed on combined arms in Part 1A.

Progression-Free Survival (PFS) is the time from randomization or treatment start until the first documented disease progression or death from any cause, whichever occurs first, assessed per RECIST v1.1. Disease progression is defined as at least a 20% increase in the sum of diameters of target lesions (minimum 5 mm absolute increase) or appearance of new lesions. Participants without progression or death are censored at the date of last adequate tumor assessment. PFS is typically analyzed using Kaplan-Meier estimates and reported in months.

All treated participants. Part 1A was for dose finding and to assess initial safety. The efficacy analysis was pre-defined to be analyzed on combined arms in Part 1A.

Progression-Free Survival Rate (PFSR) is the percentage of participants who remain alive without disease progression, assessed per RECIST v1.1. Disease progression is defined as at least a 20% increase in the sum of diameters of target lesions (minimum 5 mm absolute increase) or appearance of new lesions. Participants without progression or death by the time point are considered event-free

All treated participants. Part 1A was for dose finding and to assess initial safety. The efficacy analysis was pre-defined to be analyzed on combined arms in Part 1A.