NCT06952010

Brief Summary

This is a phase 1, first-in-human, open-label, dose-escalation study of XB628, a first-in-class bispecific antibody natural killer (NK) cell engager that targets NK group 2 member A (NKG2A), an inhibitory receptor on NK cells, and programmed cell death-ligand 1 (PD-L1).

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
75

participants targeted

Target at P75+ for phase_1

Timeline
18mo left

Started May 2025

Typical duration for phase_1

Geographic Reach
1 country

11 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress41%
May 2025Nov 2027

First Submitted

Initial submission to the registry

April 23, 2025

Completed
7 days until next milestone

First Posted

Study publicly available on registry

April 30, 2025

Completed
1 day until next milestone

Study Start

First participant enrolled

May 1, 2025

Completed
2.1 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 31, 2027

Expected
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

November 30, 2027

Last Updated

May 14, 2026

Status Verified

May 1, 2026

Enrollment Period

2.1 years

First QC Date

April 23, 2025

Last Update Submit

May 12, 2026

Conditions

Solid TumorAdvanced Solid TumorMetastatic Solid TumorImmune Sensitive Tumor

Keywords

XB628Solid tumorAdvanced solid tumorMetastatic solid tumorImmune sensitive tumorPD-L1

Outcome Measures

Primary Outcomes (2)

  • Number of Participants with Dose Limiting Toxicities (DLTs)

    21 days

  • Number of Participants with Serious Adverse Events (SAEs), Treatment-emergent Adverse Events (TEAEs), and Adverse Events (AEs) Leading to Dose Withholding, Treatment Discontinuation, or Death

    27 months

Secondary Outcomes (10)

  • Area Under the Concentration-time Curve (AUC) of XB628

    25 months

  • Maximum Plasma Concentration (Cmax) of XB628

    25 months

  • Time to Maximum Concentration (Tmax) of XB628

    25 months

  • Elimination Half-life (T1/2) of XB628

    25 months

  • Apparent Clearance (CL/F) of XB628

    25 months

  • +5 more secondary outcomes

Study Arms (1)

XB628

EXPERIMENTAL

Group(s) of participants with recurrent advanced or metastatic solid tumors will receive escalating dose levels doses of XB628.

Biological: XB628

Interventions

XB628BIOLOGICAL

Intravenous infusion(s)

XB628

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1.
  • Minimum life expectancy of ≥ 12 weeks.
  • Have a recurrent advanced or metastatic solid tumor that is histologically or cytologically confirmed.
  • Adequate organ and marrow function.
  • Not amenable to curative treatment with surgery or radiation.
  • Received at least 1 line of prior systemic anticancer therapy in the recurrent or metastatic setting.
  • Acceptable alternative therapy was received, refused, intolerable, or no longer effective.
  • Capable of understanding and complying with the protocol requirements and provide signed informed consent according to the protocol and local requirements.

You may not qualify if:

  • Primary brain tumors or known active brain metastases.
  • Major surgery (eg, gastrointestinal surgery, removal or biopsy of brain metastasis) within 4 weeks before the first dose of study treatment.
  • Received radiation therapy within 1 week before the first dose of study treatment or clinically relevant ongoing complications from prior radiation therapy.
  • Received prior therapy targeting NK cells (eg, monalizumab).
  • A woman of childbearing potential has a positive serum pregnancy test within 7 days prior to study treatment.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (11)

Exelixis Clinical Site #5

San Francisco, California, 94158, United States

RECRUITING

Exelixis Clinical Site #4

New Haven, Connecticut, 06520, United States

RECRUITING

Exelixis Clinical Site #8

Tampa, Florida, 33612, United States

RECRUITING

Exelixis Clinical Site #10

Boston, Massachusetts, 02114, United States

RECRUITING

Exelixis Clinical Site #11

Boston, Massachusetts, 02114, United States

RECRUITING

Exelixis Clinical Site #6

St Louis, Missouri, 63108, United States

RECRUITING

Exelixis Clinical Site #7

New York, New York, 10029, United States

RECRUITING

Exelixis Clinical Site #1

Hickory, North Carolina, 28602, United States

RECRUITING

Exelixis Clinical Site #3

Nashville, Tennessee, 37203, United States

RECRUITING

Exelixis Clinical Site #9

Houston, Texas, 77030, United States

RECRUITING

Exelixis Clinical Site #2

San Antonio, Texas, 78229, United States

RECRUITING

MeSH Terms

Conditions

Neoplasm Metastasis

Condition Hierarchy (Ancestors)

Neoplastic ProcessesNeoplasmsPathologic ProcessesPathological Conditions, Signs and Symptoms

Study Officials

  • Medical Director

    Exelixis

    STUDY DIRECTOR

Central Study Contacts

Exelixis Clinical Trials

CONTACT

1-888-EXELIXIS (888-393-5494)druginfo@exelixis.com

Backup or International

CONTACT

650-837-7400

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NA
Masking
NONE
Purpose
TREATMENT
Intervention Model
SEQUENTIAL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

April 23, 2025

First Posted

April 30, 2025

Study Start

May 1, 2025

Primary Completion (Estimated)

May 31, 2027

Study Completion (Estimated)

November 30, 2027

Last Updated

May 14, 2026

Record last verified: 2026-05

Data Sharing

IPD Sharing
Will not share

Locations

US(11)