Trial Outcomes & Findings for Phase 2 Study of the Monoclonal Antibody MGAH22 (Margetuximab) in Patients With Relapsed or Refractory Advanced Breast Cancer (NCT NCT01828021)

Last Updated: 2025-03-13

Results Overview

Response based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria based on Cycle 2, Day 21 computed tomography (CT) scans. Response is categorized as complete response (CR): disappearance of all target lesions, confirmed at ≥ 4 weeks; partial response (PR): ≥ 30% decrease in target lesions from baseline, confirmed at ≥ 4 weeks; progressive disease (PD): ≥ 20% increase over smallest sum observed with an absolute increase of at least 5 mm, or appearance of new lesions; and stable disease (SD): neither PR or PD criteria met. A Simon two-stage design was planned in which an initial cohort of 21 patients was treated. If 2 or more responses (PR or CR) are seen at the first tumor re-evaluation on day 21 of Cycle 2, the study would be expanded to include up to 41 patients (20 additional patients in Cohort 2, the second stage of the study) in order to determine whether further development of the drug is warranted (5 or more responses in 41 evaluable patients).

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

25 participants

Primary outcome timeframe

Cycle 2, Day 21

Results posted on

2025-03-13

Participant Flow

Enrollment occurred at 6 US oncology centers -- 4 academic institutions and 2 clinical research centers, between May 2013 and November 2016.

Participant milestones

Participant milestones
Measure	Margetuximab Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody Margetuximab was administered by IV infusion at a dose of 6.0 mg/kg on Days 1, 8, and 15 of each 28-day cycle or or 15 mg/kg every 3 weeks of each 21-day cycle
Overall Study STARTED	25
Overall Study COMPLETED	0
Overall Study NOT COMPLETED	25

Reasons for withdrawal

Reasons for withdrawal
Measure	Margetuximab Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody Margetuximab was administered by IV infusion at a dose of 6.0 mg/kg on Days 1, 8, and 15 of each 28-day cycle or or 15 mg/kg every 3 weeks of each 21-day cycle
Overall Study Adverse Event	5
Overall Study Lack of Efficacy	17
Overall Study Withdrawal by Subject	2
Overall Study Ileal obstruction, unrelated	1

Baseline Characteristics

Phase 2 Study of the Monoclonal Antibody MGAH22 (Margetuximab) in Patients With Relapsed or Refractory Advanced Breast Cancer

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Margetuximab n=25 Participants Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody
Age, Continuous	60.5 Years STANDARD_DEVIATION 10.08 • n=5 Participants
Sex: Female, Male Female	25 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	2 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	2 Participants n=5 Participants
Race (NIH/OMB) White	20 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants
Region of Enrollment United States	25 participants n=5 Participants
Eastern Cooperative Oncology Group (ECOG) Performance Status Performance Status 0	14 Participants n=5 Participants
Eastern Cooperative Oncology Group (ECOG) Performance Status Performance Status 1	11 Participants n=5 Participants

PRIMARY outcome

Timeframe: Cycle 2, Day 21

Population: All patients with baseline tumor evaluation, received any amount of study drug, and had a tumor evaluation at Cycle 2 Day 21

Outcome measures

Outcome measures
Measure	Margetuximab n=22 Participants Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody
Best Overall Response Stable Disease	6 participants
Best Overall Response Progressive Disease	12 participants
Best Overall Response Not Done	4 participants
Best Overall Response Complete Response	0 participants
Best Overall Response Partial Response	0 participants

SECONDARY outcome

Timeframe: Day 49

Population: All patients with baseline tumor measurement, at least one dose of study drug, and Cycle 2 Day 21 tumor assessment

Response rate is the proportion of patients achieving a best response of complete response or partial response when such responses are confirmed at least 28 days after initial observation of response. Response based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria based on Cycle 2, Day 21 computed tomography (CT) scans. Response is categorized as complete response (CR): disappearance of all target lesions, confirmed at ≥ 4 weeks; partial response (PR): ≥ 30% decrease in target lesions from baseline, confirmed at ≥ 4 weeks; progressive disease (PD): ≥ 20% increase over smallest sum observed with an absolute increase of at least 5 mm, or appearance of new lesions; and stable disease (SD): neither PR or PD criteria met.

Outcome measures

Outcome measures
Measure	Margetuximab n=22 Participants Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody
Response Rate	0 Participants

Adverse Events

Margetuximab

Serious events: 6 serious events

Other events: 24 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Margetuximab n=25 participants at risk Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody
Gastrointestinal disorders Ascites	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Diarrhea	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Nausea	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Pancreatitis	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Small intestinal obstruction	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Vomiting	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Hepatobiliary disorders Bile duct obstruction	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Hepatobiliary disorders Portal hypertension	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Renal and urinary disorders Renal failure acute	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Cardiac disorders Supraventricular extrasystoles	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Cardiac disorders Ventricular extrasystoles	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Alanine aminotransferase increased	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Aspartate aminotransferase increased	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Metastases to meninges	4.0% 1/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days

Other adverse events

Other adverse events
Measure	Margetuximab n=25 participants at risk Monotherapy of Anti-HER2 monoclonal antibody Margetuximab: Anti-HER2 monoclonal antibody
Gastrointestinal disorders Nausea	36.0% 9/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Vomiting	24.0% 6/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Diarrhea	20.0% 5/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Abdominal pain	12.0% 3/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Gastrointestinal disorders Ascites	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
General disorders Fatigue	24.0% 6/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
General disorders Chest pain	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
General disorders Chills	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Nervous system disorders Headache	16.0% 4/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Nervous system disorders Neuropathy periphera	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Injury, poisoning and procedural complications Infusion related reaction	20.0% 5/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Injury, poisoning and procedural complications Procedural nausea	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Alanine aminotransferase increased	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Aspartate aminotransferase increased	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Blood alkaline phosphatase increased	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Ejection fraction decreased	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Investigations Lymphoctye count decreased	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Respiratory, thoracic and mediastinal disorders Cough	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Respiratory, thoracic and mediastinal disorders Dyspnea	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Musculoskeletal and connective tissue disorders Back pain	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Blood and lymphatic system disorders Anemia	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Metabolism and nutrition disorders Decreased appetite	12.0% 3/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Psychiatric disorders Anxiety	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Psychiatric disorders Depression	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Renal and urinary disorders Renal failure acute	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days
Vascular disorders Hypertension	8.0% 2/25 • Adverse events were collected from time of consent until End of Study visit; average time on treatment was 35.6 days

Additional Information

VP, Scientific Communications

TerSera Therapeutics LLC

Phone: 1-844-334-4035

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place