GB5121 in Adult Subjects With Relapsed/Refractory CNS Lymphoma


About this study

The purpose of this 3-part study, comprising a phase 1b dose escalation, dose expansion, and a phase 2, is to assess the safety, tolerability, dose-limiting toxicity(ies), maximum tolerated dose, and/or optimal biological dose, determine the recommended phase 2 dose, preliminary anti-tumor activity and efficacy of the recommended phase 2 dose of GB5121.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

1. Patients must have histologically/cytologically confirmed primary central nervous
system lymphoma (PCNSL), primary vitreoretinal lymphoma (PVRL), or CNS-only
involvement of a systemic B-cell lymphoma.

2. All patients must have relapsed/refractory disease and must have received all possible
standard-of-care CNS-directed therapy treatment regimens or patients for which further
standard-of-care treatment options are contraindicated or declined.

3. Patients must be able to tolerate gadolinium-enhanced magnetic resonance imaging (MRI)
scans, or contrast-enhanced computed tomography (CT).

4. Patients with parenchymal lesions must have baseline imaging (gadolinium-enhanced MRI
or if contraindicated, contrast-enhanced CT, of the brain) within 28 days prior to
first study drug dose. For patients with leptomeningeal disease only, cerebrospinal
fluid (CSF) cytology must document lymphoma cells and/or imaging findings consistent
with leptomeningeal disease after informed consent and prior to first study dose (at
the discretion of the Investigator).

5. Patients with parenchymal lesions must have measurable disease (disease that has at
least one lesion on imaging ≥ 10 mm in the longest diameter) on imaging
(gadolinium-enhanced MRI or if contraindicated, contrast-enhanced CT, of the brain)
prior to first study dose.

6. Patients must be able to tolerate and consent for a lumbar puncture and/or have
pre-existing placement of an Ommaya reservoir, unless clinically contraindicated.

7. Patients must have a performance status of 0, 1, or 2 on the Eastern Cooperative
Oncology Group (ECOG) Performance Scale.

8. Demonstrate adequate bone marrow and organ function.

Exclusion Criteria:

1. Patients are concurrently using other approved or investigational antineoplastic

2. Patients have an active concurrent malignancy requiring active therapy.

3. Patients are allergic to components of the study drug.

4. Patients have a known bleeding diathesis (eg, von Willebrand's disease) or hemophilia.

5. Patients who require therapeutic anticoagulation, including dual antiplatelet agents.
Patients who have received therapeutic anticoagulation, including dual antiplatelet
agents, within 5 half-lives of the anticoagulant or 14 days, whichever is longer,
prior to starting the study drug. Patients who require the use of antiplatelet agents
should be discussed with the Sponsor's Medical Monitor.

6. Patients have significant abnormalities on screening electrocardiogram (ECG) and
active and significant cardiovascular disease such as uncontrolled or symptomatic
arrhythmias, congestive heart failure, uncontrolled hypertension, valvular disease,
pericarditis, or myocardial infarction within 6 months of screening.

7. Patients with any of the following will be excluded:

1. A marked baseline prolongation of QT/QTc interval (eg, repeated demonstration of
a QTc interval > 480 ms [CTCAE grade 2]) using Frederica's QT correction formula.

2. A history of additional risk factors for Torsades de Pointes (eg, heart failure,
hypokalemia, family history of long QT syndrome).

3. The use of concomitant medications that prolong the QT/QTc interval.

8. Patients are known to have a history of active or chronic infection with hepatitis C
virus (HCV), hepatitis B virus (HBV), as determined by serologic tests.

9. Known history of infection with human immunodeficiency virus (HIV).

10. Patients are known to have an uncontrolled active infection.

11. Patients have a history of stroke or intracranial hemorrhage within 6 months prior to

12. Patients have a life-threatening illness, medical condition, or organ system
dysfunction that, in the opinion of the Investigator, could compromise the subject's
safety or put the study outcomes at undue risk.

13. Women who are pregnant or nursing (lactating).

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Eligibility last updated 10/18/22. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Arushi Khurana, M.B.B.S.

Closed for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Allison Rosenthal, D.O.

Closed for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

Jacksonville, Fla.

Mayo Clinic principal investigator

Han Tun, M.D.

Closed for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

More information


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