Study to Evaluate Safety and Tolerability of XmAb13676 in Patients With CD20-expressing Hematologic Malignancies

Inclusion Criteria

• Able to provide written informed consent
• Diagnosis of either Non-CLL B cell malignancy or CLL/SLL
• Ineligible for or have exhausted standard therapeutic options and have relapsed or refractory disease
• ECOG performance status 0-2
• Fertile patients must agree to use highly effective contraception during and for 4 weeks after last dose of XmAb13676
• Able and willing to complete the entire study Additional Patient Inclusion Criteria for the DLBCL Cohort (Expansion Phase)
• Histologically confirmed diagnosis (specified by 2016 World Health Organization) of DLBCL or transformed low-grade lymphoma with measurable disease
• Patient must be refractory or have relapsed after 2 or more standard therapeutic options, at least one of which must have included anti-CD20 antibody therapy.
• Not a candidate for or refusing treatment with hematopoietic stem cell transplantation Additional Patient Inclusion Criteria for the Follicular Lymphoma Cohort (Expansion Phase)
• Diagnosis of follicular lymphoma Grades 1-3a
• Patient must be ineligible for or have exhausted standard therapeutic options and have had 2 or more prior systemic regimens. Additional Patient Inclusion Criteria for the Mantle Cell Lymphoma Cohort (Expansion Phase)
• Diagnosis of mantle cell lymphoma
• Patient must be ineligible for or have exhausted standard therapeutic options and have had 2 or more prior systemic regimens. Additional Patient Inclusion Criteria for the Waldenström Macroglobulinemia Cohort (Expansion Phase)
• Diagnosis of Waldenström macroglobulinemia
• Patient must be ineligible for or have exhausted standard therapeutic options and have had 2 or more prior systemic regimens. Additional Patient Inclusion Criteria for Richter Transformation Cohort (Expansion Phase)
• Diagnosis of Richter transformation Additional Patient Inclusion Criteria for Other Indolent Lymphomas Cohort (Expansion Phase)
• Diagnosis of other indolent B-cell, non-Hodgkin's lymphomas, specifically the following: MALT lymphoma, nodal marginal zone lymphoma, and splenic marginal zone lymphoma (NOTE: SLL is not eligible)
• Patient must be ineligible for or have exhausted standard therapeutic options and have had 2 or more prior systemic regimens.

Exclusion Criteria

• Cytotoxic chemotherapy, radiotherapy, or immunotherapy including other anti-CD20 antibodies within 4 weeks, or small molecule or investigational agents within 6 elimination half-lives of the first dose of XmAb13676
• Prior allogeneic stem cell or solid organ transplantation
• Failure to recover from Grade 3 or 4 toxicity from previous treatment
• Multiple myeloma/plasma cell leukemia or B cell acute lymphoblastic leukemia
• Known intolerance to CD20 monoclonal antibody therapy
• History of primary central nervous system lymphoma or neoplastic central nervous system disease
• Platelet count < 50 x 10^9/L
• Absolute neutrophil count < 1.0 x 10^9/L
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) at screening > 3x upper limit of normal (ULN)
• Bilirubin > 1.5 mg/dL unless prior diagnosis and documentation of ongoing hemolysis or Gilbert's syndrome has been made)
• Estimated creatinine clearance < 50 40 mL/min
• Active/uncontrolled autoimmune disease
• Clinically significant cardiac/cardiovascular disease, or pulmonary compromise
• Seizure disorder
• History of stroke with the past year6 mos prior to study entry
• History or evidence of a clinically unstable/uncontrollable disorder, condition or disease other than primary malignancy, that in the opinion of the Investigator would pose a risk to the patient safety or interfere with the study evaluation, procedures or completion
• Evidence of any serious bacterial, viral, parasitic or systemic fungal infections within the 30 days prior to study entry
• Positive test for human immunodeficiency virus (HIV) or hepatitis C (HCV) antibodies (unless HCV viral load test by PCR is negative)
• Positive test for HbsAg, or positive test for HBcAb (unless serology is positive due to recent intravenous immunoglobulin therapy). HBcAb positivity will be allowed if HBsAb is present.
• Patient is pregnant or breast feeding, or planning to become pregnant while enrolled in the study, up to the End of Study visit
• Positive urine pregnancy test (ie, urine human chorionic gonadotropin) at screening

Trial Phase Phase I

Trial Type Treatment

Lead Organization
Xencor, Inc.

• Primary ID XmAb13676-01
• Secondary IDs NCI-2016-01843
• Clinicaltrials.gov ID NCT02924402