Skip to content

Study to Evaluate Mechanisms of Acquired Resistance to Panitumumab

Phase 2 Study of Panitumumab Plus Irinotecan Followed by Panitumumab Plus AMG 479 in Subjects With Metastatic Colorectal Carcinoma Expressing Wild Type KRAS and Refractory to Oxaliplatin-or Irinotecan- and Oxaliplatin-containing Regimens to Evaluate Mechanisms of Acquired Resistance to Panitumumab

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00891930
Enrollment
74
Registered
2009-05-01
Start date
2009-05-05
Completion date
2013-07-22
Last updated
2024-07-17

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

Conditions

Metastatic Colorectal Cancer

Keywords

wild-type KRAS, panitumumab, biomarker, mechanisms of acquired resistance, metastatic colorectal cancer

Brief summary

This study is designed to evaluate the mechanism(s) of resistance to the anti-epidermal growth factor receptor (EGFR) antibody panitumumab given in combination with irinotecan in metastatic colorectal carcinoma (mCRC) patients with wild-type Kirsten rat sarcoma-2 virus oncogene (KRAS) tumor status at the time of initial diagnosis.

Detailed description

In Part 1, all participants will undergo a baseline tumor biopsy and will receive panitumumab with irinotecan. Participants who respond or have stable disease will continue to receive treatment until radiographically-confirmed disease progression. These participants will then undergo a second tumor biopsy and blood sampling and then proceed to Part 2 of the study. Participants with radiographically confirmed disease progression at the time of the first tumor measurement will undergo blood sampling and proceed directly to Part 2. In Part 2, participants will receive panitumumab with ganitumab. In both parts of the study, panitumumab and irinotecan (Part 1) and panitumumab and ganitumab (Part 2) will be administered every 2 weeks until disease progression, intolerability, withdrawal of consent, death, or unless otherwise indicated by the study team.

Interventions

BIOLOGICALPanitumumab

Panitumumab 6 mg/kg administered via IV infusion over 60 minutes

BIOLOGICALGanitumab

AMG 479 12 mg/kg adminstered by IV infusion over 60 minutes

DRUGIrinotecan

Irinotecan starting dose of 180 mg/m² adminstered via IV infusion

Sponsors

NantBioScience, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

* Histologically or cytologically confirmed metastatic adenocarcinoma of the colon or rectum; * Subjects with wild-type KRAS tumor status confirmed by an Amgen approved central laboratory assessment or an experienced local laboratory assessment of archival tumor tissue (preferably from the primary tumor); * Radiographic evidence of disease progression while on or ≤ 6 months after completion of treatment with irinotecan- and oxaliplatin- or oxaliplatin-based chemotherapy for mCRC; * Radiographic measurement of tumor burden done within 28 days prior to Day 1 (start of treatment with investigational product); * At least 1 uni-dimensionally measurable lesion ≥ 20 mm using conventional computed tomography (CT) or magnetic resonance imaging (MRI) or ≥ 10 mm by spiral CT scan per modified RECIST v1.0. Lesion must not be chosen from a previously irradiated field, unless there has been documented disease progression in that field after irradiation and prior to enrollment. All sites of disease must be evaluated; * At least 1 tumor (preferably a metastasis or unresected primary tumour) that is amenable to core biopsy, as determined by the clinician who will perform the biopsy; * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1; * A life expectancy estimate of ≥ 3 months; * Willing to undergo two serial core biopsy procedures of tumors (metastasis or unresected primary); * other criteria may apply

Exclusion criteria

* History of other primary cancer, unless: * Malignancy treated with curative intent and with no known active disease present for ≥ 3 years before enrollment and felt to be at low risk for recurrence by the treating physician, * Adequately treated non-melanomatous skin cancer or lentigo maligna without evidence of disease, * Adequately treated cervical carcinoma in situ without evidence of disease, * Prostatic intraepithelial neoplasia without evidence of prostate cancer; * History of prior or concurrent central nervous system (CNS) metastases; * Prior treatment with anti-EGFR (eg, panitumumab, cetuximab or small molecule inhibitors (eg, erlotinib, gefitinib); * Prior treatment with monoclonal antibodies directed against insulin-like growth factor-1 receptor (IGF-1R) or small molecule inhibitors directed against IGF-1R; * Use of systemic chemotherapy or radiotherapy ≤ 21 days before enrollment. Subjects must have recovered from acute toxicities related to radiotherapy; * Use of any antibody therapy (eg, bevacizumab) ≤ 42 days before enrolment; * Use of anti-tumor therapies including prior experimental agents or approved anti-tumor small molecules ≤ 30 days before enrolment; * Known allergy or hypersensitivity to any component of panitumumab, irinotecan, or AMG 479; * Known uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) polymorphisms predisposing to increased irinotecan toxicity; * History of irinotecan intolerance that may interfere with planned treatment; * History of interstitial lung disease (eg, pneumonitis, pulmonary fibrosis) or evidence of interstitial lung disease on baseline chest CT scan; * Clinically significant cardiovascular disease (including myocardial infarction, unstable angina, symptomatic congestive heart failure, serious uncontrolled cardiac arrhythmia) ≤ 1 year before enrolment; * Active inflammatory bowel disease or other active bowel disease causing chronic diarrhea (defined as ≥ grade 2 per Common Terminology Criteria for Adverse Events (CTCAE) version 3.0); * Known positive test(s) for human immunodeficiency virus (HIV) infection, hepatitis C virus, acute or chronic active hepatitis B infection; * Major surgical procedure ≤ 28 days before enrollment or minor surgical procedure ≤ 14 days before enrollment. Subjects must have recovered from surgery related toxicities. Core biopsy, central venous catheter placement, fine needle aspiration, thoracentesis, or paracentesis is not considered a major or minor surgical procedure; - Other investigational procedures or drugs (ie, participation in another clinical study) ≤ 30 days before enrolment; * other criteria may apply

Design outcomes

Primary

MeasureTime frameDescription
PFS Hazard RatioFrom baseline up to 152 weeks (from baseline to the time of the second biopsy prior to entering part 2) .KRAS mutation status changed from wild-type at baseline to mutant at time of second biopsy in part 1, as measured by the PFS hazard ratio. Hazard ratio is presented as wild-type: mutant
Objective Response Rate in Part 2From time of randomization until confirmed complete response or partial response (part 2: up to 119 weeks)Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.

Secondary

MeasureTime frameDescription
Progression-Free Survival for Part 2119 weeks from the start of part 2, up to a maximum duration of 152 weekTime from the start of Part 2 to the first date of disease progression per the modified RECIST v1.0 or death by any cause, initiating a new line of antitumor therapy, or receiving study treatment in Part 2, whichever is earlier. Disease progression is a \>= 20% increase in the sum of the longest diameter of the target lesions as compared to the smallest sum while on study per RECIST v1.0.
Overall Survival for Part 1from first dose of investigational product up to 152 weeksTime from the first dose of investigational product to death from any cause in Part 1.
Overall Survival for Part 2from the start of Part 2 up to 119 weeksTime from the start of Part 2 to death from any cause.
Objective Response Rate for Part 1from first dose of investigational product up to 152 weeksPer Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Objective Response (OR) = CR + PR.
Duration of Response for Part 1from first dose of investigational product up to 152 weeksTime from first confirmed objective response to disease progression per modified RECIST v1.0 in Part 1. An objective response is defined as a confirmed complete response or partial response per modified RECIST v1.0 criteria during the treatment period. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Objective Response (OR) = CR + PR; Disease progression is a \>= 20% increase in the sum of the longest diameter of the target lesions as compared to the smallest sum while on study.
Part 2 Time to Response and Duration of ResponseFrom time of randomization until confirmed complete response or partial response (part 2: up to 119 weeks)Time to response was defined as the time from study day 1 to the first observation of an objective response (confirmed complete response or partial response using modified Response Evaluation Criteria in Solid Tumors \[RECIST\]). Duration of response was the time from the first observation of an objective response to the subsequent time of disease progression (per modified RECIST or clinical progression, whichever came first) or death due to any cause. Objective response = a tumor response assessment of either complete response or partial response per modified Response Evaluation Criteria in Solid Tumors \[RECIST\]. Per RECIST: a complete response is the disappearance of all target lesions; a partial response is defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.
Time to Response for Part 1from first dose of investigational product up to 152 weeksTime from the first dose of investigational product to the date of first confirmed objective response in Part 1. An objective response is defined as a confirmed complete response or partial response per modified RECIST v1.0 criteria during the treatment period. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Objective Response (OR) = CR + PR.
Progression-Free Survival for Part 1from first dose of investigational product up to 152 weeksTime from the first dose of investigational product to the first date of disease progression per the modified RECIST v1.0 or death by any cause, initiating a new line of antitumor therapy, or receiving study treatment in Part 2, whichever is earlier in Part 1. Disease progression is a \>= 20% increase in the sum of the longest diameter of the target lesions as compared to the smallest sum while on study per RECIST v1.0

Participant flow

Pre-assignment details

Upon radiographically confirmed disease progression per modified RECIST version 1.0, eligible subjects from part 1 proceeded to part 2 of the study to receive panitumumab plus ganitumab.

Participants by arm

ArmCount
Part 1
Participants received panitumumab (6 mg/kg starting dose) with irinotecan (starting dose of 180 mg/m²) every 2 weeks (Q2W) during Part 1. Upon radiographically confirmed disease progression, participants proceeded to Part 2 of the study and received treatment with panitumumab (6 mg/kg starting dose) and ganitumab (12 mg/kg starting dose) Q2W.
74
Part 2
Participants received panitumumab (6 mg/kg starting dose) with irinotecan (starting dose of 180 mg/m²) every 2 weeks (Q2W) during Part 1. Upon radiographically confirmed disease progression, participants proceeded to Part 2 of the study and received treatment with panitumumab (6 mg/kg starting dose) and ganitumab (12 mg/kg starting dose) Q2W.
36
Total110

Withdrawals & dropouts

PeriodReasonFG000
Part 1 Panitumumab + IrinotecanDeath66
Part 1 Panitumumab + IrinotecanFull Consent Withdrawn2
Part 1 Panitumumab + IrinotecanLost to Follow-up1
Part 2 Panitumumab + AMG479Death30
Part 2 Panitumumab + AMG479Full Consent Withdrawn1

Baseline characteristics

CharacteristicPart 1TotalPart 2
Age, Continuous
Part 1
62.2 years
STANDARD_DEVIATION 9.8
62.2 years
STANDARD_DEVIATION 9.8
Age, Continuous
Part 2
62.9 years
STANDARD_DEVIATION 10.1
62.9 years
STANDARD_DEVIATION 10.1
Race (NIH/OMB)
Part 1
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 1
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 1
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 1
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 1
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 1
Unknown or Not Reported
1 Participants1 Participants0 Participants
Race (NIH/OMB)
Part 1
White
73 Participants73 Participants0 Participants
Race (NIH/OMB)
Part 2
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 2
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 2
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 2
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 2
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Part 2
Unknown or Not Reported
0 Participants1 Participants1 Participants
Race (NIH/OMB)
Part 2
White
0 Participants35 Participants35 Participants
Sex: Female, Male
Part 1
Female
27 Participants27 Participants0 Participants
Sex: Female, Male
Part 1
Male
47 Participants47 Participants0 Participants
Sex: Female, Male
Part 2
Female
0 Participants11 Participants11 Participants
Sex: Female, Male
Part 2
Male
0 Participants25 Participants25 Participants
Subjects With Metastatic Colorectal Carcinoma Expressing Wild-type KRAS and Refractory to Oxaliplati
Part 1
74 Participants74 Participants0 Participants
Subjects With Metastatic Colorectal Carcinoma Expressing Wild-type KRAS and Refractory to Oxaliplati
Part 2
0 Participants36 Participants36 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
66 / 7430 / 36
other
Total, other adverse events
74 / 7435 / 36
serious
Total, serious adverse events
26 / 748 / 36

Outcome results

Primary

Objective Response Rate in Part 2

Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.

Time frame: From time of randomization until confirmed complete response or partial response (part 2: up to 119 weeks)

ArmMeasureValue (NUMBER)
Part 1Objective Response Rate in Part 20.00 percentage of participants
Primary

PFS Hazard Ratio

KRAS mutation status changed from wild-type at baseline to mutant at time of second biopsy in part 1, as measured by the PFS hazard ratio. Hazard ratio is presented as wild-type: mutant

Time frame: From baseline up to 152 weeks (from baseline to the time of the second biopsy prior to entering part 2) .

ArmMeasureValue (NUMBER)
Part 1PFS Hazard Ratio0.365 months
p-value: 0.013Regression, Cox
Secondary

Duration of Response for Part 1

Time from first confirmed objective response to disease progression per modified RECIST v1.0 in Part 1. An objective response is defined as a confirmed complete response or partial response per modified RECIST v1.0 criteria during the treatment period. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Objective Response (OR) = CR + PR; Disease progression is a \>= 20% increase in the sum of the longest diameter of the target lesions as compared to the smallest sum while on study.

Time frame: from first dose of investigational product up to 152 weeks

ArmMeasureValue (MEDIAN)
Part 1Duration of Response for Part 17.7 months
Secondary

Objective Response Rate for Part 1

Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Objective Response (OR) = CR + PR.

Time frame: from first dose of investigational product up to 152 weeks

ArmMeasureValue (NUMBER)
Part 1Objective Response Rate for Part 121.62 percentage of participants
Secondary

Overall Survival for Part 1

Time from the first dose of investigational product to death from any cause in Part 1.

Time frame: from first dose of investigational product up to 152 weeks

ArmMeasureValue (MEDIAN)
Part 1Overall Survival for Part 111.6 months
Secondary

Overall Survival for Part 2

Time from the start of Part 2 to death from any cause.

Time frame: from the start of Part 2 up to 119 weeks

ArmMeasureValue (MEDIAN)
Part 1Overall Survival for Part 27.6 months
Secondary

Part 2 Time to Response and Duration of Response

Time to response was defined as the time from study day 1 to the first observation of an objective response (confirmed complete response or partial response using modified Response Evaluation Criteria in Solid Tumors \[RECIST\]). Duration of response was the time from the first observation of an objective response to the subsequent time of disease progression (per modified RECIST or clinical progression, whichever came first) or death due to any cause. Objective response = a tumor response assessment of either complete response or partial response per modified Response Evaluation Criteria in Solid Tumors \[RECIST\]. Per RECIST: a complete response is the disappearance of all target lesions; a partial response is defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Time frame: From time of randomization until confirmed complete response or partial response (part 2: up to 119 weeks)

Population: Due to no subjects having complete or partial responses, these Secondary Outcomes were not summarized.

Secondary

Progression-Free Survival for Part 1

Time from the first dose of investigational product to the first date of disease progression per the modified RECIST v1.0 or death by any cause, initiating a new line of antitumor therapy, or receiving study treatment in Part 2, whichever is earlier in Part 1. Disease progression is a \>= 20% increase in the sum of the longest diameter of the target lesions as compared to the smallest sum while on study per RECIST v1.0

Time frame: from first dose of investigational product up to 152 weeks

ArmMeasureValue (MEDIAN)
Part 1Progression-Free Survival for Part 14.6 months
Secondary

Progression-Free Survival for Part 2

Time from the start of Part 2 to the first date of disease progression per the modified RECIST v1.0 or death by any cause, initiating a new line of antitumor therapy, or receiving study treatment in Part 2, whichever is earlier. Disease progression is a \>= 20% increase in the sum of the longest diameter of the target lesions as compared to the smallest sum while on study per RECIST v1.0.

Time frame: 119 weeks from the start of part 2, up to a maximum duration of 152 week

ArmMeasureValue (MEDIAN)
Part 1Progression-Free Survival for Part 21.7 months
Secondary

Time to Response for Part 1

Time from the first dose of investigational product to the date of first confirmed objective response in Part 1. An objective response is defined as a confirmed complete response or partial response per modified RECIST v1.0 criteria during the treatment period. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Objective Response (OR) = CR + PR.

Time frame: from first dose of investigational product up to 152 weeks

ArmMeasureValue (MEAN)Dispersion
Part 1Time to Response for Part 12.0 monthsStandard Deviation 0.4

Source: ClinicalTrials.gov · Data processed: Mar 8, 2026