First in Human Study of M6223

A DLT is defined as any Grade ≥ 3 non-hematologic AE or any Grade ≥ 4 hematologic AE according to the NCI-CTCAE, occurring during the DLT observation period (28 days from first administration of study intervention) that is not clearly related to the underlying disease or any previous or concomitant medication, concomitant disease or unrelated illness. A DLT must be confirmed by the Safety Monitoring Committee. DLT is considered if the following related AEs occur: • Grade ≥ 3 neutropenia with clinical signs/symptoms (e.g., febrile neutropenia). • Grade ≥ 3 thrombocytopenia with medically concerning bleeding. • A study intervention-related treatment-emergent AE that in the opinion of the SMC is of potential clinical significance such that further dose escalation would expose participants to unacceptable risk. • Grade ≥ 3 hematological AE with symptoms that require growth factor support or transfusion to prevent further damage to the participant.

An adverse event (AE) is defined as any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether considered related to the study intervention or not. A serious AE was an AE that resulted in any of the following outcomes: death; life threatening; persistent/significant disability/incapacity; initial or prolonged inpatient hospitalization; congenital anomaly/birth defect or was otherwise considered medically important. TEAEs were defined as events that started or worsened after first dose of study intervention until 30 days after last dose. TEAEs included both serious and non-serious TEAEs. Treatment-related TEAEs is defined as reasonably related to the study intervention.

An adverse event (AE) is any untoward medical occurrence in a participant temporally associated with the use of the study intervention, regardless of causality. A serious AE results in death, is life-threatening, requires/prolongs hospitalization, causes disability/incapacity, leads to a congenital anomaly/birth defect, or is otherwise medically significant. Treatment-emergent adverse events (TEAEs) are those that begin or worsen after the first dose through 30 days post-treatment, and include both serious and non-serious events. Treatment-related TEAEs are those reasonably related to the study intervention. Severity is graded per CTCAE v24.1: Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe/medically significant), Grade 4 (life-threatening/disabling), Grade 5 (death related to AE).

Number of participants with clinically meaningful change from baseline in laboratory parameters were reported. Clinically meaningful abnormalities (identified as laboratory values having CTCAE grades >= 3). Laboratory investigation included hematology, biochemistry, urinalysis, and coagulation.

Number of participants with clinically significant change from baseline in ECG parameters were reported. Clinical Significance was decided by the investigator. The 12-lead ECGs were recorded after the participants have rested for at least 5 minutes in supine position. The parameters included heart rate (HR), Respiratory Rate, Pulse Rate, QRS, QT and QTcB calculated by the Bazett formula.

Vital signs included oral body temperature, systolic blood pressure, diastolic blood pressure, and pulse rate. Clinical Relevance was decided by the investigator. Number of participants with clinically relevant change from baseline in vital signs were reported. Clinical relevance was defined as increase more than equal to (>=) 3° temperature, >40 beats heart rate increase, >40 mmHG increase in systolic or diastolic blood pressure, >10 breaths in respiratory rate increase.

The number of participants who experienced worse post baseline shift were assessed as per ECOG performance status score recorded during the treatment. The ECOG score is categorized as Grade 0, 1, 2, 3 and 4 where Grade 0=fully active, Grade 1=restricted in physically strenuous activity, Grade 2=unable to carry out any work activities, Grade 3=capable of only limited self-care and Grade 4=completely disabled.

Area under the serum concentration-time curve from time zero to the last sampling time at which the concentration is at or above lower limit of quantification (LLQ). AUC0-t was calculated according to the mixed log linear trapezoidal rule. The full form of unit of measure h*mcg/mL is hours · micrograms per milliliter.

Area under the serum concentration time curve from time zero to infinity, calculated as AUC0 t + AUCextra. AUCextra represents an extrapolated value obtained by Clast/λz, where Clast is the calculated serum concentration at the last sampling time point at which the measured serum concentration is at or above LLQ and λz is elimination rate constant.

Area under the concentration-time curve from time zero up to time Tau, where Tau is the dosing interval.

Maximum measured serum concentration, calculated from the serum concentration vs. time profile of the individual participants.

Ctrough is the concentration prior to study drug administration.

Time taken to reach maximum concentration of M66223 after admistration is reported.

Terminal half-life is the time measured for the concentration to decrease by one half. Terminal half-life is calculated by dividing the natural logarithm to the base e (Log e) multiplied by (*) 2/ λz, where 'λz' is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

Elimination rate constant was obtained from linear regression of the terminal phase of the log transformed concentration-time data.

Maximum measured serum concentration, calculated from the serum concentration vs. time profile of the individual participants.

Ctrough is the concentration prior to study drug administration.

Serum samples were analyzed by a validated assay method to detect the presence of antidrug antibodies (ADA). Number of participants with positive ADA were reported.

The ORR is defined as the number of participants with a documented BOR (complete response (CR) or partial response (PR)) by the investigator during treatment with avelumab plus axitinib as firstline therapy. The BOR is defined as the best tumor response recorded during the observation period. The definitions of tumor responses are as follows: Complete or PR as the best adjudication result (CR > PR > stable disease [SD] > progressive disease [PD], not Evaluable [NE]) complies with the RECIST tumor assessment guidelines as closely as possible in clinical practice.

DOR was defined for participants with a confirmed objective response as the time from first documentation of a confirmed objective response (CR or PR) according to RECIST 1.1 to the date of first documentation of objective PD or death due to any cause, whichever occurs first. CR: Disappearance of all evidence of target and non-target lesions. PR: At least 30 percent (%) reduction from baseline in sum of longest diameter (SLD) of all lesions. PD: At least a 20 percent (%) increase in the SLD, taking as reference the smallest SLD recorded from baseline or the appearance of 1 or more new lesions. DOR was determined according to RECIST v1.1 and assessed by IRC.

TTR was defined for participants who achieved objective response as time from first study drug administration to first documentation of objective tumor response (CR or PR) that was subsequently confirmed. CR was defined as a score of 1 (no uptake above background), 2 (uptake <= mediastinum), or 3 (uptake <mediastinum but <=liver) with or without a residual mass on PET 5-PS, for lymph nodes and extralymphatic sites; no new lesions; no evidence of FDG-avid disease in bone marrow. PR was defined as >=50% decrease in SPD of up to six of the largest dominant lymph nodes, no increase in size of other nodes, liver, or spleen volume, a >=50% decrease in SPD of hepatic and splenic nodules, absence of other organ involvement, and no new sites of disease.

Disease control rate was defined as percentage of participants with disease control. Disease Control (DC) was defined as the best overall response of CR, PR, or stable disease (SD). CR: score of 1 (no uptake above background), 2 (uptake <= mediastinum), or 3 (uptake less than <mediastinum but <=liver) with or without a residual mass on Positron Emission Tomography 5-Point Scale, for lymph nodes and extra lymphatic sites; no new lesions; no evidence of fluorodeoxyglucose -avid disease in bone marrow. PR: >=50% decrease in SPD of up to six of the largest dominant lymph nodes, no increase in size of other nodes, liver, or spleen volume, a >=50% decrease in Sum of the Products of Diameters of hepatic and splenic nodules, absence of other organ involvement, and no new sites of disease. SD: <50% decrease in SDP of up to 6 dominant, measurable nodes and extranodal sites; no criteria for progressive disease met.

Progression Free Survival (PFS) time is defined as the time from start date of treatment to the date of the first documentation of objective progression of disease (PD) or death due to any cause, whichever occurs first. The tumor response will be determined according to RECIST 1.1 and assessed by the investigator.

Overall survival was defined as the time (in months) from first study drug administration to the date of death due to any cause. Participants last known to be alive were censored at date of last contact. Analysis was performed using Kaplan-Meier method.