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Capecitabine and 131I-huA33 in Patients With Metastatic Colorectal Cancer

Phase I Trial of Oral Capecitabine Combined With 131I-huA33 in Patients With Metastatic Colorectal Cancer

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00291486
Enrollment
19
Registered
2006-02-14
Start date
2003-10-31
Completion date
2012-08-29
Last updated
2022-10-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Colorectal Neoplasms

Brief summary

The purpose of this clinical trial is to determine whether it is safe to treat patients with advanced colorectal cancer, with humanised A33 antibody tagged with radioactive iodine (131I-huA33) in combination with chemotherapy (capecitabine).

Detailed description

This clinical trial tests the combination of humanised A33 monoclonal antibody tagged with radioactive iodine 131 (131I-huA33) together with capecitabine chemotherapy in patients with advanced colorectal cancer. When colorectal cancer has spread to other organs, it is generally considered incurable but with a limited number of treatment options. Colorectal cancer cells express proteins on their surface known as antigens, and one of these is called the A33 antigen. An antibody which targets the A33 antigen was initially developed in the mouse and found to bind to human colorectal cancer cells. Because humans developed immune reactions when given the mouse antibody, an antibody, which is more like normal human antibodies, was developed (humanised A33 antibody). In order to increase its effectiveness, radioactive iodine (131I) has been attached to the antibody so that the antibody can deliver radiation directly to colorectal cancer cells. Previous studies have shown that both the unlabelled humanised A33 antibody as well as the humanised A33 antibody tagged with radioactive iodine can be administered safely to humans with no major allergic reactions. The addition of chemotherapy to radiolabelled 131I-huA33 may result in a treatment that is more effective for the treatment of colorectal cancer than either agent alone. The purpose of this study is to determine whether it is safe to give humanised A33 antibody tagged with radioactive iodine together with chemotherapy. Different dose levels of radioactive iodine attached to a constant dose of antibody will be given together with a fixed total daily capecitabine chemotherapy dose. Providing humanised A33 antibody tagged with radioactive iodine and chemotherapy is tolerated well without major side effects, the dose of capecitabine chemotherapy given with 131I-huA33 will also be increased in order to determine the highest dose that can be given safely in combination with radio-labelled 131I-huA33. The effectiveness of the treatment combination against advanced colorectal cancer will also be assessed. Patients with advanced colorectal cancer who have never previously received chemotherapy using capecitabine may be eligible to participate in the study. A total of between 15 and 30 patients are expected to be recruited. Screening blood tests will be performed to determine eligibility, as well as baseline heart and lung function tests and appropriate scans to measure tumour size and assess radiation within the body. Patients will be given a trace-labelled (small radiation dose) infusion of 131I-huA33 into a vein followed a week later by the treatment infusion of 131I-huA33. The first infusion will be given as an outpatient, but for the second, patients will be hospitalized and confined to a radiation-shielded room until radiation levels fall to safe limits. Oral iodine drops will also be given for 28 days in order to protect the thyroid gland from the effects of radioactive iodine. Capecitabine chemotherapy will be taken orally and will commence at the time of the treatment infusion. Each cycle of capecitabine chemotherapy involves the medication being taken twice per day for a total of 14 days followed by 7 days rest. A total of 4 cycles of capecitabine will be given after the treatment infusion. Blood samples will be taken just before the treatment infusion and then weekly for 13 weeks. There will be weekly physical examinations until 9 weeks after the treatment infusion and again at 12 weeks. Total study duration is 13 weeks from the trace-labelled infusion of 131I-huA33, that is 12 weeks from the treatment infusion of 131I-huA33. Patients will only receive one treatment infusion of 131I-huA33 antibody.

Interventions

DRUGCapecitabine

Capecitabine was administered orally at doses between 1000 and 1500 mg/m2/day depending on assigned dose level for 14 days per 21-day cycle. Daily doses were rounded to the nearest 150 mg.

DRUG131I-huA33 (131-Iodine on humanised monoclonal antibody A33)

All patients received a dose of 5 mg huA33 conjugated to 5-8 mCi 131I. The therapy dose of 131I-huA33 comprised a constant protein dose of 10 mg/m2 huA33 regardless of dose level. The 131I-huA33 therapy dose was determined by the assigned dose level (i.e. 20, 30 or 40 mCi/m2 131I).

Sponsors

National Cancer Institute (NCI)
CollaboratorNIH
Ludwig Institute for Cancer Research
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Metastatic colorectal cancer. * Histologically or cytologically proven colorectal cancer. * Measurable disease on CT scan with at least one lesion \>/= 2cm diameter (to allow adequate infusion imaging). * Expected survival of at least 4 months. * ECOG performance status 0-2. * Vital laboratory parameters should be within normal range including: 1. Neutrophils \>/= 1.5 x 10\^9/L; 2. Platelets \>/= 150 x 10\^9/L; 3. Serum bilirubin \</= 34 micromol/L; 4. Calculated creatinine clearance \> 50 ml/min. * Age \>/= 18 years. * Able and willing to give valid written informed consent.

Exclusion criteria

* Previous treatment with capecitabine. * Untreated active metastatic disease to the central nervous system (new or enlarging lesions on CT or MRI), or within 3 months of treatment (ie surgery or radiotherapy) for brain metastases. * Other serious illnesses, eg, serious infections requiring antibiotics, bleeding disorders. * Liver involvement with metastatic disease \> 50% liver volume. * Chemotherapy, radiation therapy, or immunotherapy within 4 weeks before study entry (6 weeks for nitrosoureas). * Previous external beam irradiation except if: (i) it was for standard adjuvant pelvic radiation for rectal cancer; (ii) it was for localised irradiation for skin cancer; or (iii) the sum total of all previous external beam irradiation port areas is not greater than 25% of the total red marrow. * Previous treatment with a monoclonal antibody or antibody fragment AND a positive huA33 human anti-human antibody (HAHA) titre. * Concomitant treatment with systemic corticosteroids. Topical or inhalational corticosteroids are permitted. * Mental impairment that may compromise the ability to give informed consent and comply with the requirements of the study. * Lack of availability of the patient for clinical and laboratory follow-up assessment. * Participation in any other clinical trial involving another investigational agent within 4 weeks prior to enrollment. * Pregnancy or breastfeeding. * Women of childbearing potential: Refusal or inability to use effective means of contraception.

Design outcomes

Primary

MeasureTime frameDescription
Number of Patients With Dose-Limiting Toxicities (DLT)7 weeksAdverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE v3.0). DLT was defined as any of the following related events: Any grade 2 or greater allergic reaction related to huA33. Any grade ≥ 3 non-haematological toxicity related to 131I-huA33 or capecitabine. * These toxicities included palmar plantar erythema, but skin rash thought to be related to huA33 protein was not a DLT as previous studies have shown no relation of this toxicity to dose of huA33 or radioiodine dose. * Capecitabine cardiotoxicity grade ≥ 3 - including vasospasm, acute coronary syndrome and arrhythmia, necessitated the cessation of study drug in the affected patient but were not considered DLT as these are recognized as idiosyncratic in nature and not known to be related to capecitabine dose. Any grade ≥ 4 neutropenia ≥ 7 days in duration or any thrombocytopenia with a platelet count \< 10 x 10\^9/L.

Secondary

MeasureTime frameDescription
Biodistribution of 131I-huA33 Measured by Whole Body Clearance and Normal Organ Clearance Reported as Mean Biological Half-life (T1/2 Biological) After Initial 131I-huA33 Infusion1 weekT1/2 biological is the clearance of the isotope from the whole body. Following the initial 131I-huA33 infusion, gamma camera scans were acquired over a 1 week period (1-4 hours, Day 1, Day 2 or 3, and Day 4 or 5). Whole body clearance, or biological half time, T1/2 biological, was calculated from the whole body anterior and posterior planar images. A region of interest (ROI) was calculated to encompass the whole body, and for each ROI at each time point, the mean counts per pixel per minute was normalised to imaging time point Day 1.
Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial Infusion1 weekGamma camera imaging with anterior and posterior whole body scans using conjugate view methodology were performed on four occasions (1-4 hours, Day 1, Day 2 or 3, and Day 4 or 5) following completion of the intravenous initial infusion. Dosimetric analysis was performed on the series of gamma camera whole-body planar images acquired in all patients following the first infusion. Organ radioactivity content was estimated from the geometric mean of anterior and posterior regions of interest counts. The counts for each organ were corrected for background using regions of interest drawn adjacent to each organ where whole body thickness was comparable.
Mean Total Tumor Dose of 131I-huA335 weeksGamma camera imaging were performed on four occasions (1-4 hours, Day 1, Day 2 or 3, and Day 4 or 5) following completion of the initial infusion and 7+2 days post-therapy infusion in week 2, and again in week 3 or 4 and week 5 following the therapy infusion. Dosimetry analysis was performed on the series of gamma camera whole-body planar images. Tumor radioactivity content after the initial infusion was estimated from the geometric mean of anterior and posterior regions of interest counts. The counts for each organ were corrected for background using regions of interest drawn adjacent to each tumor. Resultant counts were converted to activity using a camera sensitivity factor calculated from a gamma camera standard of known activity which was scanned at the same time.
Pharmacokinetics (PK) of 131I-huA33 as Measured by T½α and T½β (Half Lives of the Initial and Terminal Phases of Disposition, Respectively)5 weeksBlood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).
Pharmacokinetics (PK) of 131I-huA33 as Measured by Clearance (CL)5 weeksBlood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 13II-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).
Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).13 weeksTumor responses were evaluated using appropriate imaging and categorized according to RECIST at Screening (within 2 weeks of the first dose of study treatment), and at week 13. Per RECIST, target lesions are categorized as follows: complete response (CR): disappearance of all target lesions; partial response (PR): ≥ 30% decrease in the sum of the longest diameter of target lesions; progressive disease (PD): ≥ 20% increase in the sum of the longest diameter of target lesions; stable disease (SD): small changes that do not meet above criteria (Therasse et al 2000).
Pharmacokinetics (PK) of 131I-huA33 as Measured by the Volume of the Central Compartment (V1)5 weeksBlood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).
Pharmacokinetics (PK) of 131I-huA33 as Measured by Maximum Serum Concentration (Cmax)5 weeksBlood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).
Pharmacokinetics (PK) of 131I-huA33 as Measured by Area Under the Serum Concentration Curve Extrapolated to Infinite Time (AUC)5 weeksBlood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).
Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA3313 weeksSerum samples for human anti-human antibody (HAHA) assessment were collected prior to each 131I-huA33 infusion, at weekly intervals during weeks 0-7, then alternate weeks until the end-of-study visit. Measurement of immune responses to huA33 in patients serum was performed using a BIAcore 2000 biosensor (Biacore AB, Uppsala, Sweden).
Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)5 weeksBlood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 13II-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Countries

Australia

Participant flow

Participants by arm

ArmCount
Cohort 1
20 mCi 131I-huA33, 1500 mg/m2/day capecitabine All patients received an initial dose of 5 mg huA33 conjugated to 5-8 mCi 131I on day 0. This was followed 7 ± 2 days later by inpatient administration of the therapy dose given as a single infusion of 131I-huA33 with a constant protein dose of 10 mg/m2 huA33. The 131I-huA33 therapy dose was determined by the assigned dose level (i.e. 20, 30 or 40 mCi/m2 131I). Capecitabine was administered at doses between 1000 and 1500 mg/m2/day depending on assigned dose level for 14 days per 21-day cycle for 4 cycles. Daily doses were rounded to the nearest 150 mg.
3
Cohort 2
30 mCi 131I-huA33, 1500 mg/m2/day capecitabine All patients received an initial dose of 5 mg huA33 conjugated to 5-8 mCi 131I on day 0. This was followed 7 ± 2 days later by inpatient administration of the therapy dose given as a single infusion of 131I-huA33 with a constant protein dose of 10 mg/m2 huA33. The 131I-huA33 therapy dose was determined by the assigned dose level (i.e. 20, 30 or 40 mCi/m2 131I). Capecitabine was administered at doses between 1000 and 1500 mg/m2/day depending on assigned dose level for 14 days per 21-day cycle for 4 cycles. Daily doses were rounded to the nearest 150mg.
6
Cohort 3
30 mCi 131I-huA33, 1000 mg/m2/day capecitabine All patients received an initial dose of 5 mg huA33 conjugated to 5-8 mCi 131I on day 0. This was followed 7 ± 2 days later by inpatient administration of the therapy dose given as a single infusion of 131I-huA33 with a constant protein dose of 10 mg/m2 huA33. The 131I-huA33 therapy dose was determined by the assigned dose level (i.e. 20, 30 or 40 mCi/m2 131I). Capecitabine was administered at doses between 1000 and 1500 mg/m2/day depending on assigned dose level for 14 days per 21-day cycle for 4 cycles. Daily doses were rounded to the nearest 150 mg.
3
Cohort 4
40 mCi 131I-huA33, 1000 mg/m2/day capecitabine All patients received an initial dose of 5 mg huA33 conjugated to 5-8 mCi 131I on day 0. This was followed 7 ± 2 days later by inpatient administration of the therapy dose given as a single infusion of 131I-huA33 with a constant protein dose of 10 mg/m2 huA33. The 131I-huA33 therapy dose was determined by the assigned dose level (i.e. 20, 30 or 40 mCi/m2 131I). Capecitabine was administered at doses between 1000 and 1500 mg/m2/day depending on assigned dose level for 14 days per 21-day cycle for 4 cycles. Daily doses were rounded to the nearest 150 mg.
3
Cohort 5
40 mCi 131I-huA33, 1250 mg/m2/day capecitabine All patients received an initial dose of 5 mg huA33 conjugated to 5-8 mCi 131I on day 0. This was followed 7 ± 2 days later by inpatient administration of the therapy dose given as a single infusion of 131I-huA33 with a constant protein dose of 10 mg/m2 huA33. The 131I-huA33 therapy dose was determined by the assigned dose level (i.e. 20, 30 or 40 mCi/m2 131I). Capecitabine was administered at doses between 1000 and 1500 mg/m2/day depending on assigned dose level for 14 days per 21-day cycle for 4 cycles. Daily doses were rounded to the nearest 150 mg.
4
Total19

Withdrawals & dropouts

PeriodReasonFG000FG001FG002FG003FG004
Overall StudyAdverse Event03010
Overall StudyDisease progression10100
Overall StudyWithdrawal by Subject00001

Baseline characteristics

CharacteristicCohort 1Cohort 2Cohort 3Cohort 4Cohort 5Total
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
0 Participants4 Participants0 Participants0 Participants2 Participants6 Participants
Age, Categorical
Between 18 and 65 years
3 Participants2 Participants3 Participants3 Participants2 Participants13 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
1 Participants1 Participants0 Participants0 Participants0 Participants2 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
2 Participants5 Participants3 Participants3 Participants4 Participants17 Participants
Region of Enrollment
Australia
3 participants6 participants3 participants3 participants4 participants19 participants
Sex: Female, Male
Female
1 Participants2 Participants2 Participants0 Participants1 Participants6 Participants
Sex: Female, Male
Male
2 Participants4 Participants1 Participants3 Participants3 Participants13 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
deaths
Total, all-cause mortality
0 / 30 / 60 / 30 / 30 / 4
other
Total, other adverse events
3 / 36 / 63 / 33 / 34 / 4
serious
Total, serious adverse events
0 / 33 / 60 / 31 / 30 / 4

Outcome results

Primary

Number of Patients With Dose-Limiting Toxicities (DLT)

Adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE v3.0). DLT was defined as any of the following related events: Any grade 2 or greater allergic reaction related to huA33. Any grade ≥ 3 non-haematological toxicity related to 131I-huA33 or capecitabine. * These toxicities included palmar plantar erythema, but skin rash thought to be related to huA33 protein was not a DLT as previous studies have shown no relation of this toxicity to dose of huA33 or radioiodine dose. * Capecitabine cardiotoxicity grade ≥ 3 - including vasospasm, acute coronary syndrome and arrhythmia, necessitated the cessation of study drug in the affected patient but were not considered DLT as these are recognized as idiosyncratic in nature and not known to be related to capecitabine dose. Any grade ≥ 4 neutropenia ≥ 7 days in duration or any thrombocytopenia with a platelet count \< 10 x 10\^9/L.

Time frame: 7 weeks

Population: All patients who received at least one dose of study treatment.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Cohort 1Number of Patients With Dose-Limiting Toxicities (DLT)0 Participants
Cohort 2Number of Patients With Dose-Limiting Toxicities (DLT)2 Participants
Cohort 3Number of Patients With Dose-Limiting Toxicities (DLT)0 Participants
Cohort 4Number of Patients With Dose-Limiting Toxicities (DLT)0 Participants
Cohort 5Number of Patients With Dose-Limiting Toxicities (DLT)0 Participants
Secondary

Biodistribution of 131I-huA33 Measured by Whole Body Clearance and Normal Organ Clearance Reported as Mean Biological Half-life (T1/2 Biological) After Initial 131I-huA33 Infusion

T1/2 biological is the clearance of the isotope from the whole body. Following the initial 131I-huA33 infusion, gamma camera scans were acquired over a 1 week period (1-4 hours, Day 1, Day 2 or 3, and Day 4 or 5). Whole body clearance, or biological half time, T1/2 biological, was calculated from the whole body anterior and posterior planar images. A region of interest (ROI) was calculated to encompass the whole body, and for each ROI at each time point, the mean counts per pixel per minute was normalised to imaging time point Day 1.

Time frame: 1 week

Population: All patients who received the initial infusion of 131I-huA33.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Biodistribution of 131I-huA33 Measured by Whole Body Clearance and Normal Organ Clearance Reported as Mean Biological Half-life (T1/2 Biological) After Initial 131I-huA33 InfusionWhole Body Clearance (T1/2 biologic)219.56 hoursStandard Deviation 62.81
Cohort 1Biodistribution of 131I-huA33 Measured by Whole Body Clearance and Normal Organ Clearance Reported as Mean Biological Half-life (T1/2 Biological) After Initial 131I-huA33 InfusionNormal Organ Clearance in the Liver (T1/2 biological - liver)62.29 hoursStandard Deviation 22.05
Cohort 1Biodistribution of 131I-huA33 Measured by Whole Body Clearance and Normal Organ Clearance Reported as Mean Biological Half-life (T1/2 Biological) After Initial 131I-huA33 InfusionNormal Organ Clearance in the kidney (T1/2 biological - kidney)104.89 hoursStandard Deviation 56.22
Secondary

Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)

Blood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 13II-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Time frame: 5 weeks

Population: CL is a key parameter to assess the impact of capecitabine on huA33 therapy. The doses of huA33 were the same, results are presented by capecitabine dose level in patients who received study therapy and had PK samples taken. The results excluded the following patients due to curve fit instability; 1 after the initial infusion, and 1 after the therapy infusion. Another was excluded from the results measured after the therapy infusion due to a positive human anti-human antibody (HAHA) in Week 1.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)Initial dose CL34.88 ml/hrStandard Deviation 9.81
Cohort 1Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)Therapy dose CL26.88 ml/hrStandard Deviation 6.66
Cohort 2Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)Initial dose CL40.54 ml/hrStandard Deviation 7.41
Cohort 2Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)Therapy dose CL39.41 ml/hrStandard Deviation 5.55
Cohort 3Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)Initial dose CL34.65 ml/hrStandard Deviation 1.85
Cohort 3Impact of Capecitabine on 131I-huA33 Clearance (CL) as Measured by Initial and Therapy Dose Clearance (CL)Therapy dose CL35.53 ml/hrStandard Deviation 4.76
p-value: 0.361ANOVA
Secondary

Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial Infusion

Gamma camera imaging with anterior and posterior whole body scans using conjugate view methodology were performed on four occasions (1-4 hours, Day 1, Day 2 or 3, and Day 4 or 5) following completion of the intravenous initial infusion. Dosimetric analysis was performed on the series of gamma camera whole-body planar images acquired in all patients following the first infusion. Organ radioactivity content was estimated from the geometric mean of anterior and posterior regions of interest counts. The counts for each organ were corrected for background using regions of interest drawn adjacent to each organ where whole body thickness was comparable.

Time frame: 1 week

Population: All patients who received the initial infusion of 131I-huA33.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial InfusionLiver0.12 cGy/MBqStandard Deviation 0.03
Cohort 1Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial InfusionSpleen0.18 cGy/MBqStandard Deviation 0.06
Cohort 1Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial InfusionKidney0.14 cGy/MBqStandard Deviation 0.05
Cohort 1Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial InfusionLung0.09 cGy/MBqStandard Deviation 0.03
Cohort 1Mean Specific Absorbed Dose of 131I-huA33 for Normal Organs Calculated From the Initial InfusionRed Marrow0.056 cGy/MBqStandard Deviation 0.011
Secondary

Mean Total Tumor Dose of 131I-huA33

Gamma camera imaging were performed on four occasions (1-4 hours, Day 1, Day 2 or 3, and Day 4 or 5) following completion of the initial infusion and 7+2 days post-therapy infusion in week 2, and again in week 3 or 4 and week 5 following the therapy infusion. Dosimetry analysis was performed on the series of gamma camera whole-body planar images. Tumor radioactivity content after the initial infusion was estimated from the geometric mean of anterior and posterior regions of interest counts. The counts for each organ were corrected for background using regions of interest drawn adjacent to each tumor. Resultant counts were converted to activity using a camera sensitivity factor calculated from a gamma camera standard of known activity which was scanned at the same time.

Time frame: 5 weeks

Population: All patients who received the initial and therapy infusions and had tumors of sufficient size for accurate tumor quantitation and dosimetry. Nine patients had tumors too small to be analyzed. Results are presented by the radiolabeled dose of huA33 given as well as all patients.

ArmMeasureValue (MEAN)Dispersion
Cohort 1Mean Total Tumor Dose of 131I-huA3313.83 GyStandard Deviation 7.61
Cohort 3Mean Total Tumor Dose of 131I-huA3313.15 GyStandard Deviation 7.26
Cohort 4Mean Total Tumor Dose of 131I-huA3314.89 GyStandard Deviation 9.08
Secondary

Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33

Serum samples for human anti-human antibody (HAHA) assessment were collected prior to each 131I-huA33 infusion, at weekly intervals during weeks 0-7, then alternate weeks until the end-of-study visit. Measurement of immune responses to huA33 in patients serum was performed using a BIAcore 2000 biosensor (Biacore AB, Uppsala, Sweden).

Time frame: 13 weeks

Population: All patients who received at least one dose of study therapy and had HAHA measured at the respective timepoint.

ArmMeasureGroupCategoryValue (COUNT_OF_PARTICIPANTS)
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentPositive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentNegative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Negative HAHA2 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Positive HAHA0 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Negative HAHA3 Participants
Cohort 1Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentPositive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentNegative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Negative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Negative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Negative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Negative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Negative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Negative HAHA6 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Negative HAHA4 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Negative HAHA3 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Positive HAHA0 Participants
Cohort 2Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Negative HAHA3 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Negative HAHA1 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Negative HAHA3 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Positive HAHA1 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Negative HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Positive HAHA0 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Positive HAHA1 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Negative HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Negative HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentNegative HAHA3 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Positive HAHA0 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Positive HAHA1 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Negative HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentPositive HAHA0 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Positive HAHA0 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Positive HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Positive HAHA0 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Negative HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Negative HAHA2 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Positive HAHA0 Participants
Cohort 3Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Negative HAHA2 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Positive HAHA1 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Negative HAHA3 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Negative HAHA3 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Positive HAHA0 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Positive HAHA0 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Negative HAHA2 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Negative HAHA2 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Positive HAHA0 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Positive HAHA1 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Positive HAHA1 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentPositive HAHA0 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Negative HAHA2 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Negative HAHA3 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Positive HAHA1 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Positive HAHA0 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Negative HAHA2 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Negative HAHA2 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Positive HAHA1 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentNegative HAHA3 Participants
Cohort 4Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentNegative HAHA4 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Positive HAHA2 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Negative HAHA4 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Positive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Pre-treatmentPositive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 6Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 2Negative HAHA2 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Positive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Positive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 1Positive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 8Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Positive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 12-13Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 4Negative HAHA3 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 3Positive HAHA1 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 10-11Positive HAHA0 Participants
Cohort 5Number of Patients With Human Anti-human Antibodies (HAHA) to 131I-huA33Week 5Positive HAHA0 Participants
Secondary

Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).

Tumor responses were evaluated using appropriate imaging and categorized according to RECIST at Screening (within 2 weeks of the first dose of study treatment), and at week 13. Per RECIST, target lesions are categorized as follows: complete response (CR): disappearance of all target lesions; partial response (PR): ≥ 30% decrease in the sum of the longest diameter of target lesions; progressive disease (PD): ≥ 20% increase in the sum of the longest diameter of target lesions; stable disease (SD): small changes that do not meet above criteria (Therasse et al 2000).

Time frame: 13 weeks

Population: All patients who received at least one dose of study treatment and were evaluable for response. One patient in Cohort 5 was not evaluable due to the patient's request to discontinue the study prior to this evaluation.

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
Cohort 1Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PR0 Participants
Cohort 1Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).CR0 Participants
Cohort 1Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PD2 Participants
Cohort 1Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).SD1 Participants
Cohort 2Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).CR0 Participants
Cohort 2Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PR1 Participants
Cohort 2Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PD2 Participants
Cohort 2Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).SD3 Participants
Cohort 3Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PR0 Participants
Cohort 3Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PD1 Participants
Cohort 3Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).CR0 Participants
Cohort 3Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).SD2 Participants
Cohort 4Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).CR0 Participants
Cohort 4Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).SD1 Participants
Cohort 4Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PD2 Participants
Cohort 4Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PR0 Participants
Cohort 5Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).SD3 Participants
Cohort 5Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).CR0 Participants
Cohort 5Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PD0 Participants
Cohort 5Number of Patients With Tumour Response Assessed by Response Evaluation Criteria in Solid Tumors (RECIST).PR0 Participants
Secondary

Pharmacokinetics (PK) of 131I-huA33 as Measured by Area Under the Serum Concentration Curve Extrapolated to Infinite Time (AUC)

Blood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Time frame: 5 weeks

Population: In all cohorts, both doses of huA33 were the same. The amount of radioactivity administered does not impact the PK of the protein. The results excluded the following patients due to curve fit instability; 1 after the initial infusion, and 1 after the therapy infusion. Another was excluded from the results measured after the therapy infusion due to a positive human anti-human antibody (HAHA) in Week 1.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by Area Under the Serum Concentration Curve Extrapolated to Infinite Time (AUC)AUC after initial 131I-huA33 infusion130.43 mcg.hr/mLStandard Deviation 36.35
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by Area Under the Serum Concentration Curve Extrapolated to Infinite Time (AUC)AUC after therapy 131I-huA33 infusion592.46 mcg.hr/mLStandard Deviation 161.33
Secondary

Pharmacokinetics (PK) of 131I-huA33 as Measured by Clearance (CL)

Blood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 13II-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Time frame: 5 weeks

Population: In all cohorts, the doses of huA33 were the same. The amount of radioactivity administered does not impact the PK of the protein. The results are presented for all patients who received study therapy and had PK samples taken. The results excluded the following patients due to curve fit instability; 1 after the initial infusion, and 1 after the therapy infusion. Another was excluded from the results measured after the therapy infusion due to a positive human anti-human antibody (HAHA) in Week 1.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by Clearance (CL)CL after initial 131I-huA33 infusion36.72 mL/hrStandard Deviation 8.01
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by Clearance (CL)CL after therapy 131I-huA33 infusion32.60 mL/hrStandard Deviation 8.02
Comparison: Comparison of CL between initial infusion and therapy infusionp-value: 0.144t-test, 1 sided
Secondary

Pharmacokinetics (PK) of 131I-huA33 as Measured by Maximum Serum Concentration (Cmax)

Blood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Time frame: 5 weeks

Population: In all cohorts, both doses of huA33 were the same. The amount of radioactivity administered does not impact the PK of the protein. The results excluded the following patients due to curve fit instability; 1 after the initial infusion, and 1 after the therapy infusion. Another was excluded from the results measured after the therapy infusion due to a positive human anti-human antibody (HAHA) in Week 1.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by Maximum Serum Concentration (Cmax)Cmax after initial 131I-huA33 infusion1.53 mcg/mLStandard Deviation 0.24
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by Maximum Serum Concentration (Cmax)Cmax after therapy 131I-huA33 infusion5.52 mcg/mLStandard Deviation 0.77
Secondary

Pharmacokinetics (PK) of 131I-huA33 as Measured by T½α and T½β (Half Lives of the Initial and Terminal Phases of Disposition, Respectively)

Blood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Time frame: 5 weeks

Population: In all cohorts, both doses of huA33 were the same. The amount of radioactivity administered does not impact the PK of the protein. The results are presented for all patients who received study therapy and had PK samples taken. Two patients were not included in the determination of mean parameter values due to curve fit instability (one after initial infusion and one after therapy infusion) and one due to a positive human anti-human antibody (HAHA) response in Week 1 (therapy infusion).

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by T½α and T½β (Half Lives of the Initial and Terminal Phases of Disposition, Respectively)T½α after initial 131I-huA33 infusion15.78 hoursStandard Deviation 4.68
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by T½α and T½β (Half Lives of the Initial and Terminal Phases of Disposition, Respectively)T½α after therapy 131I-huA33 infusion28.63 hoursStandard Deviation 8.93
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by T½α and T½β (Half Lives of the Initial and Terminal Phases of Disposition, Respectively)T½β after initial 131I-huA33 infusion100.24 hoursStandard Deviation 20.92
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by T½α and T½β (Half Lives of the Initial and Terminal Phases of Disposition, Respectively)T½β after therapy 131I-huA33 infusion152.60 hoursStandard Deviation 49.59
Secondary

Pharmacokinetics (PK) of 131I-huA33 as Measured by the Volume of the Central Compartment (V1)

Blood samples for pharmacokinetics (PK) were drawn in week 0 immediately pre-initial 131I-huA33 infusion; then 5 minutes, 60 minutes and 2 hours post-initial 131I-huA33 infusion, Day 1, Day 2 or Day 3, Day 4 or Day 5. In week 1, PK samples were collected immediately pre-therapy 131I-huA33 infusion, 5 minutes, 24 ± 2 hours and approximately 7 days post-therapy 131I-huA33 infusion, then weekly until 4 weeks post therapy. Pharmacokinetic calculations were performed on serum 131I-huA33 data using a curve fitting Program (WinNonLin version 5.2; Pharsight Co., Mountain View, CA).

Time frame: 5 weeks

Population: In all cohorts, both doses of huA33 were the same. The amount of radioactivity administered does not impact the PK of the protein. The results excluded the following patients due to curve fit instability; 1 after the initial infusion, and 1 after the therapy infusion. Another was excluded from the results measured after the therapy infusion due to a positive human anti-human antibody (HAHA) in Week 1.

ArmMeasureGroupValue (MEAN)Dispersion
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by the Volume of the Central Compartment (V1)V1 after initial 131I-huA33 infusion3204.26 mLStandard Deviation 605.59
Cohort 1Pharmacokinetics (PK) of 131I-huA33 as Measured by the Volume of the Central Compartment (V1)V1 after therapy 131I-huA33 infusion3363.69 mLStandard Deviation 649.64

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026