A Safety and Activity Study of SBT6050 in Combination With Other HER2-directed Therapies for HER2-positive Cancers

Silverback Therapeutics

Status and phase: Terminated; Phase 2; Phase 1

Conditions: HER2-positive Colorectal Cancer; HER2-positive Gastric Cancer; HER2-positive Breast Cancer; HER2-expressing Non-small Cell Lung Cancer

Treatments: Drug: tucatinib; Drug: SBT6050; Drug: trastuzumab; Drug: trastuzumab deruxtecan; Drug: capecitabine

Study type: Interventional

Funder types: Industry

Identifiers

NCT05091528

SBT6050-201

Details and patient eligibility

About

This study is designed to assess the safety and preliminary activity of SBT6050 in combination with trastuzumab deruxtecan (Part 1) or tucatinib plus trastuzumab +/- capecitabine (Part 2). Participants will be enrolled into each Arm based on cancer diagnosis and prior therapies.

Enrollment: 2 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Advanced or metastatic HER2-expressing (IHC 2+ or 3+) or HER2-amplified solid tumors

• Measurable disease per the the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 criteria

• Tumor lesion amenable for biopsy or able to submit an adequate recent archived tumor tissue for baseline testing, as follows:

  1. Breast cancer and colorectal cancer (CRC): archival biopsy tissue obtained after the last HER2-directed therapy (excluding trastuzumab and pertuzumab), or a fresh biopsy
  2. Gastric cancer and non-small-cell lung cancer (NSCLC): archival biopsy tissue taken within the past 12 months and after completion of last HER2-directed therapy, or a fresh biopsy

• ECOG Performance Status of 0 or 1

• Adequate hematologic, hepatic, renal, and cardiac function

Exclusion criteria

• History of allergic reactions to certain components of study treatment therapies
• Untreated brain metastases
• Currently active (or history of) autoimmune disease
• Taking the equivalent of >10 mg / day of prednisone
• Taking a medication that moderately induces CYP2C, strongly inhibits CYP2C8, or interacts with both enzymes (CYP3A and CYP2C8)
• Uncontrolled or clinically significant interstitial lung disease (ILD) / pneumonitis that requires systemic corticosteroid treatment or suspected ILD / pneumonitis
• HIV infection, active hepatitis B or hepatitis C infection

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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2 participants in 4 patient groups

SBT6050 + T-DXd (5.4 mg/kg)

Experimental group

Description:

SBT6050 plus trastuzumab deruxtecan

Treatment:

Drug: SBT6050

Drug: trastuzumab deruxtecan

Drug: trastuzumab deruxtecan

SBT6050 + T-DXd (6.4 mg/kg)

Experimental group

Description:

SBT6050 plus trastuzumab deruxtecan

Treatment:

Drug: SBT6050

Drug: trastuzumab deruxtecan

Drug: trastuzumab deruxtecan

SBT6050 + Tucatinib + Trastuzumab + Capecitabine

Experimental group

Description:

SBT6050 plus tucatinib, trastuzumab, and capecitabine

Treatment:

Drug: SBT6050

Drug: capecitabine

Drug: trastuzumab

Drug: tucatinib

SBT6050 + Tucatinib + Trastuzumab

Experimental group

Description:

SBT6050 plus tucatinib and trastuzumab

Treatment:

Drug: SBT6050

Drug: trastuzumab

Drug: tucatinib