Participants received single intravenous infusion of Berzosertib at a dose of 210 mg/m^2 on Day 2 and Day 5 in period 2 until disease progression or other criteria for study intervention discontinuation were met.

Participants received topotecan at a dose of 1.25 mg/m^2 intravenously on Days 1 through 5 of each 21-day cycle in period 2 until disease progression or other criteria for study intervention discontinuation were met.

AUC0-inf was calculated by combining AUC0-t and AUCextra. AUCextra represents an extrapolated value obtained by Clast pred/Lambda z, where Clast pred was the calculated plasma concentration at the last sampling time point at which the measured plasma concentration is at or above the Lower Limit of quantification (LLOQ) and Lambda z was the apparent terminal rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal log-linear phase.

Elimination Half Life (T1/2) was defined as the time required for the concentration or amount of drug in the body to be reduced by one-half. T1/2 was calculated by natural log 2 divided by Lambda z. Lambda z was determined from the terminal slope of the log-transformed plasma concentration curve using linear regression method.

CL is a quantitative measure of the rate at which a drug substance is removed from the body, calculated as dose divided by AUC0-infinity.

Vz is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Vz was calculated by dividing the dose with area under the concentration time curve from time zero to infinity multiplied with terminal elimination rate constant Lambda(z). Vz = Dose/AUC0-inf multiply Lambda z.

Vss is the theoretical volume that the total amount of administered drug would have to occupy (if it were uniformly distributed), to provide the same concentration as it is in blood plasma at steady state.

Cmax was obtained directly from the plasma concentration versus time curve. Cmax of total radioactivity was calculated in nanogram equivalents per milliliter (ng eq)/mL.

Area under the plasma concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule. AUC0-t was calculated in hour*nanogram equivalents per milliliter (h*[ng eq/mL]).

AUC0-inf was calculated by combining AUC0-t and AUCextra. AUCextra represents an extrapolated value obtained by Clast pred/Lambda z, where Clast pred was the calculated plasma concentration at the last sampling time point at which the measured plasma concentration is at or above the Lower Limit of quantification (LLOQ) and Lambda z was the apparent terminal rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal log-linear phase.

Elimination Half Life (T1/2) was defined as the time required for the concentration or amount of drug in the body to be reduced by one-half. T1/2 was calculated by natural log 2 divided by Lambda z. Lambda z was determined from the terminal slope of the log-transformed plasma concentration curve using linear regression method.

Cmax was obtained directly from the blood concentration versus time curve.

Area under the blood concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule.

AUC0-inf was calculated by combining AUC0-t and AUCextra. AUCextra represents an extrapolated value obtained by Clast pred/Lambda z, where Clast pred was the calculated plasma concentration at the last sampling time point at which the measured plasma concentration is at or above the Lower Limit of quantification (LLOQ) and Lambda z was the apparent terminal rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal log-linear phase.

Elimination Half Life (T1/2) was defined as the time required for the concentration or amount of drug in the body to be reduced by one-half. T1/2 was calculated by natural log 2 divided by Lambda z. Lambda z was determined from the terminal slope of the log-transformed plasma concentration curve using linear regression method.

Aeurine is defined as the amount of Berzosertib excreted in urine over the time interval from t1 (= start) and t2 (= end).

Feurine is defined as the amount of Berzosertib unchanged excreted in urine as percentage of the administered dose over the time interval t1 (= start) and t2 (= end).

Renal clearance was calculated as total amount of unchanged drug excreted in the urine between times t1 and t2 (Aeurine) divided by area under the plasma concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule.

12-lead ECG recordings included rhythm, heart rate (as measured by RR interval), PR interval, QRS duration, and QT interval. 12-lead ECG recordings were obtained after the participants have rested for at least 10 minutes in semi-supine position. Clinical significance was determined by the investigator. The number of participants with clinically significant changes from baseline in 12-lead ECG findings were reported.

An AE was defined as any untoward medical occurrence in a participant administered a pharmaceutical product, regardless of causal relationship with this treatment. Therefore, an AE can be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal product, regardless if it is considered related to the medicinal product. Serious AE: AE that resulted in any of the following outcomes: death; life threatening; persistent/significant disability/incapacity; initial/prolonged inpatient hospitalization; congenital anomaly/birth defect. TEAEs are defined as AEs that were reported or worsened on or after start of study drug dosing through the Safety Follow-up Visit. TEAEs included both serious TEAEs and non-serious TEAEs. Treatment related AEs: reasonably related to the study drug/study treatment.

Fefeces, fractions of total radioactivity excreted in feces as percentage of the administered dose between time t1 (= start) and t2 (= end).

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Fetotal, fractions of total radioactivity excreted in urine and feces as percentage of the administered dose between time t1 (= start) and t2 (= end).

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Cmax was obtained directly from the plasma concentration versus time curve.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Area under the plasma concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

AUC0-inf was calculated by combining AUC0-t and AUCextra. AUCextra represents an extrapolated value obtained by Clast pred/Lambda z, where Clast pred was the calculated plasma concentration at the last sampling time point at which the measured plasma concentration is at or above the Lower Limit of quantification (LLOQ) and Lambda z was the apparent terminal rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal log-linear phase.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Elimination Half Life (T1/2) was defined as the time required for the concentration or amount of drug in the body to be reduced by one-half. T1/2 was calculated by natural log 2 divided by Lambda z. Lambda z was determined from the terminal slope of the log-transformed plasma concentration curve using linear regression method.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

CL is a quantitative measure of the rate at which a drug substance is removed from the body, calculated as dose divided by AUC0-infinity.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Vz is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Vz was calculated by dividing the dose with area under the concentration time curve from time zero to infinity multiplied with terminal elimination rate constant Lambda(z). Vz = Dose/AUC0-inf multiply Lambda z.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Vss is the theoretical volume that the total amount of administered drug would have to occupy (if it were uniformly distributed), to provide the same concentration as it is in blood plasma at steady state.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Cmax was obtained directly from the plasma concentration versus time curve. Cmax of total radioactivity was calculated in nanogram equivalents per milliliter (ng eq)/mL.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Area under the plasma concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule. AUC0-t was calculated in hour*nanogram equivalents per milliliter (h*[ng eq/mL]).

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

AUC0-inf was calculated by combining AUC0-t and AUCextra. AUCextra represents an extrapolated value obtained by Clast pred/Lambda z, where Clast pred was the calculated plasma concentration at the last sampling time point at which the measured plasma concentration is at or above the Lower Limit of quantification (LLOQ) and Lambda z was the apparent terminal rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal log-linear phase.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Elimination Half Life (T1/2) was defined as the time required for the concentration or amount of drug in the body to be reduced by one-half. T1/2 was calculated by natural log 2 divided by Lambda z. Lambda z was determined from the terminal slope of the log-transformed plasma concentration curve using linear regression method.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Cmax was obtained directly from the blood concentration versus time curve.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Area under the blood concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

AUC0-inf was calculated by combining AUC0-t and AUCextra. AUCextra represents an extrapolated value obtained by Clast pred/Lambda z, where Clast pred was the calculated plasma concentration at the last sampling time point at which the measured plasma concentration is at or above the Lower Limit of quantification (LLOQ) and Lambda z was the apparent terminal rate constant determined by log-linear regression analysis of the measured plasma concentrations of the terminal log-linear phase.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Elimination Half Life (T1/2) was defined as the time required for the concentration or amount of drug in the body to be reduced by one-half. T1/2 was calculated by natural log 2 divided by Lambda z. Lambda z was determined from the terminal slope of the log-transformed plasma concentration curve using linear regression method.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Aeurine is defined as the amount of Berzosertib excreted in urine over the time interval from t1 (= start) and t2 (= end).

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Feurine is defined as the amount of Berzosertib unchanged excreted in urine as percentage of the administered dose over the time interval t1 (= start) and t2 (= end).

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Renal clearance was calculated as total amount of unchanged drug excreted in the urine between times t1 and t2 (Aeurine) divided by area under the plasma concentration versus time curve from time zero to the last sampling time t at which the concentration was at or above the lower limit of quantification (LLOQ). AUC0-t was calculated according to the mixed log-linear trapezoidal rule.

PK Analysis Set was a subset of the SAF included all participants who received at least one dose of IMP, in Period 1 and provide at least one measurable post-dose concentration. Here, "Overall Number of Participants Analyzed" signifies those participants who were evaluable for this outcome measure.

Vital signs included body temperature, heart rate, systolic and diastolic blood pressure and respiration rate. Number of participants with clinically significant findings in vital signs were reported. Clinical significance was decided by Investigator.

SAF included all participants who had received any dose of any study intervention.

12-lead ECG recordings included rhythm, heart rate (as measured by RR interval), PR interval, QRS duration, and QT interval. 12-lead ECG recordings were obtained after the participants have rested for at least 10 minutes in semi-supine position. Clinical significance was determined by the investigator. The number of participants with clinically significant changes from baseline in 12-lead ECG findings were reported.

SAF included all participants who had received any dose of any study intervention.

An AE was defined as any untoward medical occurrence in a participant administered a pharmaceutical product, regardless of causal relationship with this treatment. Therefore, an AE can be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal product, regardless if it is considered related to the medicinal product. Serious AE: AE that resulted in any of the following outcomes: death; life threatening; persistent/significant disability/incapacity; initial/prolonged inpatient hospitalization; congenital anomaly/birth defect. TEAEs are defined as AEs that were reported or worsened on or after start of study drug dosing through the Safety Follow-up Visit. TEAEs included both serious TEAEs and non-serious TEAEs. Treatment related AEs: reasonably related to the study drug/study treatment.

SAF included all participants who had received any dose of any study intervention.

Participants received single intravenous infusion of Berzosertib at a dose of 210 mg/m^2 on Day 2 and Day 5 in combination with topotecan at a dose of 1.25 mg/m^2 intravenously on Days 1 through 5 of each 21-day cycle in period 2 until disease progression or other criteria for study intervention discontinuation were met.

Participants received single intravenous infusion of [14C]Berzosertib at a dose of 210 milligrams per square meter (mg/m^2) on Day 1 in Period 1 and stay in clinical research unit (CRU) is required until the discharge criteria are met with a maximum confinement period of 15 days. In Period 2, participants received single intravenous infusion of Berzosertib at a dose of 210 mg/m^2 on Day 2 and Day 5 in combination with topotecan at a dose of 1.25 mg/m^2 intravenously on Days 1 through 5 of each 21-day cycle until disease progression or other criteria for study intervention discontinuation were met.