Phase 1, First-in-human, Dose-finding and Expansion Study to Evaluate XmAb®808 in Combination With Pembrolizumab in Advanced Solid Tumors

Xencor

Status and phase: Enrolling; Phase 1

Conditions: Melanoma Excluding Uveal Melanoma; TNBC - Triple-Negative Breast Cancer; Castration-resistant Prostate Cancer; Urothelial Carcinoma; Renal Cell Carcinoma, Clear Cell; Ovarian Cancer, Epithelial; Non-small Cell Lung Cancer, Squamous or Non-squamous; Colorectal Cancer; Head and Neck Squamous Cell Carcinoma

Treatments: Biological: Keytruda® (pembrolizumab); Biological: XmAb®808

Study type: Interventional

Funder types: Industry

Identifiers

NCT05585034

XmAb808-01

Details and patient eligibility

About

The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of intravenous (IV) administration of XmAb808 in combination with pembrolizumab in subjects with selected advanced solid tumors and to identify the minimum safe and biologically effective/recommended dose (RD) and schedule for XmAb808.

Full description

This is a Phase 1, open-label, first-in-human (FIH), multiple-dose, dose escalation study with cohort expansion at the RD, designed to evaluate the safety and tolerability of XmAb808 in combination with pembrolizumab. This study will be conducted in 2 parts: Part A (dose escalation) and Part B (cohort expansion).

Enrollment: 220 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria:

• Part A: Histologically confirmed advanced/metastatic castration-resistant prostate adenocarcinoma, epithelial ovarian cancer, head and neck squamous cell carcinoma, non-small cell lung cancer, urothelial carcinoma, melanoma, renal cell carcinoma, triple-negative breast cancer, or colorectal cancer that has progressed on standard therapies
• Part B: Histologically confirmed advanced/metastatic castration-resistant prostate cancer that is PD1-naïve; head and neck squamous cell carcinoma that is PD1-naïve or has progressed on prior PD1 therapy; or melanoma that is PD1-naïve or has progressed on prior PD1 therapy
• Measurable disease by RECIST 1.1; subjects with prostate cancer who have evaluable disease according to PCWG3 criteria may enroll
• Life expectancy > 3 months
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

Key Exclusion Criteria:

• Subjects currently receiving other anticancer therapies
• Any prior treatment with an investigational agent targeting CD28
• History of a life-threatening adverse event related to prior immunotherapy
• Known active central nervous system involvement by malignant disease. Subjects with previously treated brain metastases may participate provided they are radiologically and clinically stable

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Sequential Assignment

Masking: None (Open label)

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220 participants in 1 patient group

Dose Escalation and Expansion XmAb®808 administered in combination with pembrolizumab

Experimental group

Description:

XmAb®808 in combination with pembrolizumab

Treatment:

Biological: XmAb®808

Biological: Keytruda® (pembrolizumab)