Trial Outcomes & Findings for M8891 First in Human in Solid Tumors (NCT NCT03138538)

First/last participant (informed consent): 08 August 2017. Last participant completed: 16 September 2020.

This study was to be conducted in 2 parts; Part 1 was the dose escalation phase and Part 2 was the expansion phase. However, due to early termination of the study, the sponsor decided not to conduct the expansion phase (Part 2).

M8891 First in Human in Solid Tumors

A DLT was defined as the occurrence of any of following events that were judged by the study investigator, to be related to the study medication: Grade 4 liver enzyme elevation; Grade 4 neutropenia lasting \>5 days or Grade \>= 3 neutropenia with fever; Grade 4 thrombocytopenia lasting \>5 days or Grade \>=3 thrombocytopenia with clinically significant bleeding; Any treatment interruption \>7 days or \>30% of total dose in Cycle 1 due to AEs not related to the underlying disease or concomitant medication; Grade \>=3 non-hematologic toxicity excluding Grade 3 nausea or vomiting lasting \<48 hours, and resolves to \<= Grade 1 either spontaneously or with medication, Grade 3 fatigue \<= 3 days, Grade 3 hypertension in the absence of maximal medical therapy, Grade 3 rash \<= 3 days, Grade 3 electrolyte abnormality that lasts \<72 hours, is not clinically complicated, and resolves spontaneously or responds to conventional medication and Grade \>=3 single lab value increase without clinical correlate.

An Adverse event (AE) was defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease associated with the use of study drug, whether or not considered related to the study drug or worsening of pre-existing medical condition, whether or not related to study drug. A serious adverse event (SAE) 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. The term TEAE is defined as AEs starting or worsening after the first intake of the study drug. TEAEs include both Serious TEAEs and non-serious TEAEs.

Severity of adverse events (AE) were assessed by the investigator according to National Cancer Institute (NCI) Common Toxicity Criteria for Adverse Events (CTCAE) version 4.03 as Grade 1 to Grade 5. Grade 1= Mild, Grade 2=Moderate, Grade 3=Severe, Grade 4= Life-threatening and Grade 5= Death. The number of participants that experienced at least one solicited local TEAE were summarized by grade. The term TEAE is defined as AEs starting or worsening after the first intake of the study drug. TEAEs include both Serious TEAEs and non-serious TEAEs. Number of participants with Grade \>=3, \>=4 and 5 were reported.

Maximum observed plasma concentration (Cmax) was taken directly from the observed concentration-time curve.

The time to reach the maximum observed plasma concentration (tmax) was obtained directly from the concentration versus time curve.

The AUC from time zero (= dosing time) to the last sampling time (tlast) at which the concentration is at or above the lower limit of quantification (LLOQ), calculated using the mixed log-linear trapezoidal rule (linear up, log down).

The AUC from time zero (dosing time) extrapolated to infinity, based on the predicted value for the concentration at tlast, as estimated using the linear regression from the determination of the terminal first order (elimination) rate constant (lambda z). AUC0-inf = AUC0-t plus Clast pred/lambda z. Lambda Z was terminal elimination rate constant determined from the terminal slope of the log-transformed plasma concentration curve using linear regression on terminal data points of the curve. Clastpred was the last predicted quantifiable concentration.

AUC (0-tau) is the area under the plasma concentration time curve within 1 dosing interval. Calculated using the mixed log linear trapezoidal rule (linear up, log down).

Terminal half-life of M8891 in Plasma was calculated as log2/ lambda z. Lambda z was determined from the terminal slope of the log-transformed concentration curve using linear regression on terminal data points of the curve.

Lambda z was determined from the terminal slope of the log-transformed concentration curve using linear regression on terminal data points of the curve.

Apparent total body clearance of drug from plasma following extravascular administration, calculated as dose/AUC0-infinity for M8891. Area under the plasma concentration-time curve from time zero (dosing time) extrapolated to infinity of unchanged drug calculated as AUC0-t + AUCextra. AUCextra represents the extrapolated part of AUC0-infinity calculated by Clastpred/lambda z, where Clastpred is the predicted plasma concentration at the last sampling time point, calculated from the log linear regression line for lambda z determination at which the measured plasma concentration is at or above lower limit of quantification.

The apparent total body clearance of drug at steady state following extravascular administration, taking into account the fraction of dose absorbed. It is calculated as dose/AUCtau for M8891.

Apparent volume of distribution during the terminal phase following extravascular administration for M8891 was calculated. Vz/f = Dose/(AUC0-infinity multiply by Lambda z) following single dose. The AUC from time zero (dosing time) extrapolated to infinity, based on the predicted value for the concentration at tlast, as estimated using the linear regression from lambda z determination. AUC(0- inf)=AUC0-t plus Clastpred/lambda z where Clastpred was last predicted concentration. Lambda Z was terminal elimination rate constant determined from the terminal slope of the log-transformed plasma concentration curve using linear regression on terminal data points of the curve.

Racc (AUC) is defined as the accumulation factor to assess the increase in exposure until steady state is reached. Accumulation ratio for AUC was calculated as AUC, after dosing on Day 15 divided by AUC, after dosing on Day 1 of Cycle 1.

Accumulation ratio of Cmax was calculated as Cmax, after dosing on Day 15 divided by Cmax, after dosing on Day 1 of Cycle 1.

BOR was determined according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) as assessed by investigators. BOR is defined as the best response of any of the complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) recorded from the date of randomization until disease progression. CR: Disappearance of all evidence of target and non-target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 millimeter (mm). PR: At least 30% reduction from baseline in the sum of the longest diameter (SLD) of all lesions. Stable disease (SD) defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest SLD while on study. PD is defined as at least a 20 percent (%) increase in the SLD of target lesion, taking as reference the smallest SLD recorded from baseline or the appearance of 1 or more new lesions.

Clinical benefit defined as Complete Response (CR), Partial Response (PR) or Stable Disease (SD) for \>= 12 weeks. Clinical benefit was assessed according to RECIST Version 1.1. CR: defined as disappearance of all target and all non-target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 millimeter (mm). PR: At least 30% reduction from baseline in the sum of the longest diameter (SLD) of all lesions. SD: defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest SLD while on study. PD is defined as at least a 20 percent (%) increase in the SLD of target lesion, taking as reference the smallest SLD recorded from baseline or the appearance of 1 or more new lesions.

Progression-free survival (PFS) defined as the time from first study drug administration to either first observation of progressive disease (PD) (as assessed by Investigators according to RECIST v1.1) or occurrence of death due to any cause, whichever occurs first. Progressive disease (PD) defined as at least a 20% increase in sum of longest diameter (SLD) of target lesions, taking as reference the smallest SLD recorded from baseline or the appearance of 1 or more new lesions. PFS was measured using Kaplan-Meier (KM) estimates. Here the 20 mg dose level was selected for stratification as the highest dose level equal to or smaller than the median of all dose levels administered to at least 1 participant.

The laboratory measurements included hematology, biochemistry, and urinalysis values were graded with National Cancer Institute - Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.03 toxicity grades (where Grade 1 = mild, Grade 2 = moderate, Grade 3 = severe, Grade 4 = life threatening and Grade 5 = death). Number of participants with change from baseline to grade 3 or higher values for the hematology, biochemistry and urinalysis parameters were reported.

Vital sign assessments included assessments of heart rate, diastolic blood pressure, systolic blood pressure, weight, respiratory rate and temperature. Clinical relevance was assessed by the investigator. Number of participants who had any clinically meaningful change from baseline in vital signs were reported.

ECG parameters included rhythm, heart rate (as measured by RR interval), PR interval, QRS duration, QT intervals, and corrected QT(QTc) intervals. Clinical significance was determined by the investigator. Number of participants with clinically meaningful change from baseline in 12-lead ECG were reported.

ECOG PS score is widely used by doctors and researchers to assess how a participants' disease is progressing, and is used to assess how the disease affects the daily living abilities of the participant, and determine appropriate treatment and prognosis. The score ranges from Grade 0 to Grade 5, where Grade 0 = Fully active, able to carry on all pre-disease performance without restriction, Grade 1 = Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature (like light house work, office work), Grade 2 = Ambulatory and capable of all self-care but unable to carry out any work activities, Grade 3 = Capable of only limited self-care, confined to bed or chair more than 50% of waking hours and Grade 4 = Completely disabled. Cannot carry on any self-care. Totally confined to bed or chair, Grade 5 = Death. Number of participants with ECOG performance status score of 2 or higher than 2 were reported.

Objective response is defined as the percentage of participants with complete response (CR) and partial response (PR). CR is defined as disappearance of all evidence of target and non-target lesions. PR: At least 30% reduction from baseline in the sum of the longest diameter (SLD) of all lesions.