Safety, Tolerability, and Pharmacokinetic (PK) Study of DHES0815A in Participants With Human Epidermal Growth Factor Receptor (HER)2-Positive Breast Cancer

Genentech, Inc.14 enrolled

Overview

This first-in-human, Phase 1, open-label, multicenter, dose-escalation study will evaluate the safety, tolerability, and PK of DHES0815A as a single agent in participants with advanced and/or metastatic HER2-positive breast cancer for whom established treatment has proven ineffective or intolerable or is unavailable. The study may include a dose-expansion cohort (based on an ongoing assessment of the totality of data obtained in this study) to further assess safety, tolerability, PK, and preliminary anti-tumor activity.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Breast Cancer

Interventions

DHES0815A

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Key Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Measurable disease by RECIST v1.1 with at least one measurable target lesion * Locally advanced or metastatic HER2-positive breast cancer that has relapsed or is refractory to established therapies * Adequate hematologic and end-organ function * For dose-expansion cohort only: no more than two prior systemic chemotherapy-containing regimens in the advanced/metastatic setting (excluding trastuzumab emtansine, which is considered a targeted cytotoxic agent) Key Exclusion Criteria: * Treatment with chemotherapy, hormonal therapy (except hormone replacement therapy, oral contraceptives), immunotherapy, biologic therapy, radiation therapy (except palliative radiation to bony metastases), or herbal therapy as cancer therapy within 4 weeks prior to initiation of DHES0815A * History of exposure to the protocol specified doses of anthracyclines * Pregnancy, lactation, or breastfeeding * Major surgical procedure within 4 weeks prior to Day 1 * Evidence of a significant uncontrolled concomitant disease of the nervous system, pulmonary, autoimmune, renal, hepatic, endocrine, or gastrointestinal disorders; or a serious non-healing wound or fracture * Known active bacterial, viral, fungal, mycobacterial, or other infection * Clinically significant history of liver disease, including active viral or other hepatitis, current alcohol abuse, or cirrhosis * Untreated or active central nervous system (CNS) metastases * Cardiopulmonary dysfunction, including inadequate left ventricular ejection function at baseline, less than 50% by either echocardiogram (ECHO) or multiple-gated acquisition scan (MUGA) * QT interval corrected through use of Fridericia's formula (QTcF) \> 470 milliseconds (ms)

Outcomes

Primary Outcomes

Number of Participants With Adverse Events (AEs) and Serious AEs (SAEs) With Severity Determined as Per National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v4.0

AE is any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product, regardless of causal attribution. SAE is any AE that is fatal, is life threatening, requires or prolongs inpatient hospitalization, results in persistent/significant disability/incapacity and is congenital anomaly/birth defect. Severity of AEs were graded per NCI CTCAE v4.0. Grade 1: Mild; asymptomatic/mild symptoms; clinical/diagnostic observations only; or intervention not indicated; Grade 2: Moderate; minimal, local/non-invasive intervention indicated; or limiting age-appropriate instrumental activities of daily living; Grade 3: Severe/medically significant, but not immediately life-threatening: hospitalization/prolongation of hospitalization indicated; disabling/limiting self-care activities of daily living; Grade 4: Life-threatening consequences/urgent intervention indicated; Grade 5: Death related to AE.

Time frame: From Day 1 to end of study (up to approximately 39 months)

Number of Participants With Dose-limiting Toxicity (DLT)

DLT=any one events occurring during DLT assessment window: ≥15% decrease from baseline in left ventricular ejection fraction (LVEF)/≥10% decrease to \<50% LVEF; Grade ≥ 3 non-hematologic toxicity; Grade ≥4 neutropenia (absolute neutrophil count \<500 cells/microliters \[μL\]) lasting \<7 days; Grade ≥3 febrile neutropenia; Grade ≥4 anemia; Grade ≥4 thrombocytopenia; Grade 3 thrombocytopenia associated with clinically significant bleeding; Any increase in hepatic transaminase (ALT or AST) \>3\*baseline in combination with either an increase in direct bilirubin \>2\*upper limit of normal/clinical jaundice, in absence of cholestasis/other contributory factors. NCI CTCAE v4.0. was used to grade these events.Grade1: Mild; asymptomatic/mild symptoms; clinical/diagnostic observations only; Grade2: Moderate; minimal, local/non-invasive intervention indicated;Grade3: Severe/medically significant, but not immediately life-threatening;Grade4: Life-threatening consequences/urgent intervention indicated.

Time frame: From Day 1 up to Day 21

Duration of Treatment

Treatment duration was calculated from the first dose of study drug to the last dose of study drug administration.

Time frame: From Day 1 up to last dose of study drug (up to approximately 39 months)

Total Cumulative Dose

Time frame: From Day 1 up to last dose of study drug (up to approximately 39 months)

Change From Baseline in LVEF as Assessed by Echocardiogram (ECHO) or Multiple-Gated Acquisition (MUGA) Scan

LVEF is the fraction of blood (in percent) pumped out of the heart's left ventricular chamber with each heartbeat and is a measure of cardiac output for the heart. Baseline LVEF value and the change from baseline to the worst value in LVEF measurement were reported. LVEF was measured by ECHO or MUGA scan.

Time frame: Baseline, end of Cycle 1, Days 15-21 of Cycles 2, 4, and 6, and every four cycles thereafter up to the study discontinuation visit (up to approximately 39 months)

Secondary Outcomes

Concentration of DHES0815A Total Antibody

DHES0815A total antibody is one of three key pharmacokinetic analytes of DHES0815A.

Time frame: Pre-dose and 30 minutes (min) post-dose on Day 1 Cycles 1-4; 4 hour (h) post-dose on Day 1 Cycle1; post-dose on Days 2, 3, 11, 17 Cycle 1; post-dose on Days 8 and 15 Cycles 1-4; study discontinuation visit (up to approx. 39 months) (Cycle length=21 days)

Concentration of Plasma Conjugated Pyrrolo [2,1-c] [1,4] Benzodiazepine Monoamide (PDB-MA)

Conjugated PDB-MA is one of three key pharmacokinetic analytes of DHES0815A.

Concentration of Plasma Unconjugated PDB-MA

Plasma Unconjugated PDB-MA is one of three key pharmacokinetic analytes of DHES0815A.

Number of Participants With Objective Response Assessed According to Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1)

Objective response was defined as a complete response (CR) or partial response (PR) on two consecutive occasions ≥ 4 weeks apart, as determined by the investigator according to RECIST v1.1. CR, defined as disappearance of all target lesions. PR, defined as at least a 30% decrease in the sum of diameters of all target lesions, taking as reference the baseline sum of diameters, in the absence of CR. OR=CR+PR.

Time frame: From start of treatment until confirmation of CR or PR (up to approximately 39 months)

Duration of Response (DoR) Assessed According to RECIST v1.1

DOR was defined as the time from the first occurrence of a documented objective response to disease progression (PD) or death from any cause, whichever occurred first, as determined by the investigator according to RECIST v1.1. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum of diameters on study (including baseline). In addition to the relative increase of 20%, the sum of diameters must also demonstrate an absolute increase of \>/= 5 millimeters (mm).