Loncastuximab Tesirine in WM

May 18, 2026 updated by: Shayna Sarosiek, MD

A Phase II Study Evaluating Loncastuximab Tesirine in Patients With Previously Treated Waldenström Macroglobulinemia

This study is being done to examine the safety and effectiveness of loncastuximab tesirine as a possible treatment for participants with Waldenström Macroglobulinemia (WM).

The name of the study drug involved in this study is:

  • Loncastuximab tesirine

Study Overview

Status

Active, not recruiting

Detailed Description

This is a single-arm, open-label, phase II study to evaluate the safety and efficacy of loncastuximab tesirine in patients with Waldenström Macroglobulinemia (WM) who have received at least 2 prior treatments, including an anti-CD20 antibody such as rituximab and a BTK inhibitor such as ibrutinib.

The U.S. Food and Drug Administration (FDA) has not approved loncastuximab tesirine for Macroglobulinemia (WM) but it has been approved for other uses. Loncastuximab tesirine is a type of therapy called an antibody drug conjugate. This type of treatment is an antibody to CD19, a protein that is typically found on B-cells and plasma cells in patients with Macroglobulinemia (WM). This is a targeted therapy that uses an antibody (immunoglobulin) to deliver a toxin directly to the cancer.

The research study procedures include screening for eligibility and study treatment including evaluations and follow up visits.

It is expected that about 36 people will take part in this research study.

ADC Therapeutics is supporting this research study by providing funding and the study drug.

Study Type

Interventional

Enrollment (Actual)

21

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Massachusetts
      • Boston, Massachusetts, United States, 02215
        • Beth Israel Deaconess Medical Center
      • Boston, Massachusetts, United States, 02115
        • Dana Farber Cancer Institute
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Mayo Clinic
    • Washington
      • Seattle, Washington, United States, 98109
        • Fred Hutch

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Clinicopathological diagnosis of Waldenström Macroglobulinemia
  • Symptomatic disease meeting criteria for treatment using consensus panel criteria from the Second International Workshop on Waldenström macroglobulinemia.
  • At least 2 prior lines of treatment, including an anti-CD20 monoclonal antibody-containing regimen and a BTK inhibitor.
  • Age 18 years or older
  • Measurable disease, defined as presence of immunoglobulin M (IgM) paraprotein with a minimum serum IgM level of > 2 times the upper limit normal.
  • ECOG performance status ≤2 (Karnofsky ≥60%, see Appendix A)
  • Women of childbearing potential: Females of childbearing potential (FCBP) must agree to use two reliable forms of contraception simultaneously or have or will have complete abstinence from heterosexual intercourse during the following time periods related to this study: 1) while participating in the study; and 2) for at least 9 months after discontinuation from the study. FCBP must be referred to a qualified provider of contraceptive methods if needed.
  • Men must agree to use a latex condom during sexual contact with a female of childbearing potential (FCBP) even if they have had a successful vasectomy 1) while participating in the study; and 2) for at least 6 months after discontinuation from the study.
  • Participants must have normal organ and marrow function as defined below:

    • Absolute neutrophil count ≥1000/ uL. Growth factors are not permitted <14 days prior to C1D1.
    • Platelets ≥50,000/ uL. Platelet transfusions are not permitted <14 days prior to C1D1.
    • Hemoglobin ≥ 7 g/dL. RBC transfusions are not permitted <14 days prior to C1D1.
    • Total bilirubin ≤ 1.5 X ULN, or ≤3 x ULN with documented liver metastases and/or Gilbert's Disease
    • AST(SGOT)/ALT(SGPT) ≤2.5 × institutional upper limit of normal, or ≤5 X ULN with documented liver metastases
    • Creatinine clearance ≥ 30 ml/min using Cockcroft/Gault formula
  • Able to adhere to the study visit schedule and other protocol requirements.
  • Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

  • Prior treatment with CD19 targeted therapy.
  • Participants who are receiving any other investigational agents.
  • Clinically significant third space fluid accumulation (i.e., ascites requiring drainage or pleural effusion that is either requiring drainage or associated with shortness of breath) unless proven by cytology to be malignant due to WM.
  • Pregnant or breastfeeding.
  • Participants with known CNS lymphoma.
  • Participants with known history of Human Immunodeficiency Virus (HIV), chronic hepatitis B virus (HBV) or hepatitis C (HCV) requiring active treatment. Note: Participants with serologic evidence of prior vaccination to HBV (i.e., HBs Ag-, and anti-HBs+ and anti-HBC-) and positive anti-HBc from IVIG may participate.
  • Significant cardiovascular disease defined as:

    • Unstable angina within the past 6 months, or
    • History of myocardial infarction within the past 6 months
    • Any Class 3 or 4 cardiac disease as defined by the New York Heart Association Functional Classification, or
    • Uncontrolled or symptomatic arrhythmias
  • Participants with a history of Stevens-Johnson syndrome (SJS) or Toxic Epidermal Necrolysis (TEN)
  • Concurrent systemic immunosuppressant therapy.
  • Vaccinated with live, attenuated vaccines within 4 weeks of first dose of study drug.
  • Recent infection requiring systemic treatment that was completed ≤ 14 days before the first dose of the study drug.
  • Major surgery within 4 weeks of first dose of study drug.
  • Participants with ongoing alcohol or drug abuse.
  • History of a non-lymphoma malignancy, except adequately treated local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, localized prostate cancer, other adequately treated stage 1 or 2 cancer currently in complete remission, or any other cancer that is in a complete remission.
  • Prior or ongoing clinically significant illness, medical condition, surgical history, physical finding, EKG finding, or laboratory abnormality that, in the investigator's opinion, could affect the safety of the patient; alter the absorption, distribution, metabolism or excretion of the study drug; or impair the assessment of study results.
  • Participants with ongoing >grade 1 toxicities from prior therapy (alopecia any grade and/or grade 2 neuropathy are permitted).
  • Participants with clinically significant history of liver disease, including cirrhosis or hepatitis (viral, autoimmune, etc).
  • Participants who are unwilling or unable to comply with the protocol.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Loncastuximab Tesirine + Dexamethasone

Participants will be given

  • Loncastuximab Tesirine on Day 1 of every 28 day study cycle and continue for up to 6 cycles.

Participants will also receive pre-medications to reduce the chance of having a sensitivity reaction to the study treatment. Participants who tolerate the study treatment without a reaction may have pre-medications changed per determination of their doctor.

  • Dexamethasone will be given prior to study treatment on Day -1 or up to 2 hours prior to loncastuximab tesirine and the day after treatment
Administered by intravenous infusion
Other Names:
  • Zynlonta
Taken orally or administered by intravenous infusion
Other Names:
  • Decadron
  • Dexamethasone Intensol
  • Dexpak
  • Taperpak

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Overall Response Rate
Time Frame: 4 weeks up to 6 months
Overall Response Rate= Minor response (>25%-50% reduction in serum IgM from baseline) + Partial Response (>50-90% reduction in serum IgM from baseline) + Very Good Partial Response (>90% reduction in serum IgM from baseline) + Complete Response (resolution of all symptoms, normalization of serum IgM with disappearance of IgM paraprotein, resolution of any adenopathy or splenomegaly).
4 weeks up to 6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With Complete Response
Time Frame: 6 months
A complete response is defined as having resolution of WM related symptoms, normalization of serum IgM levels with complete disappearance of IgM paraprotein by immunofixation, and resolution of any adenopathy or splenomegaly.
6 months
Number of Participants With Very Good Partial Response
Time Frame: 6 months
Very Good Partial Response (VGPR): is defined as ≥90% reduction in serum IgM levels, or normalization of serum IgM levels.
6 months
Number of Participants With Partial Response
Time Frame: 6 months
Partial response (PR) is defined as achieving a ≥50% reduction in serum IgM levels.
6 months
Number of Participants With Minor Response
Time Frame: 6 months
Minor Response (MR): A minor response (MR) is defined 25-49% reduction in serum IgM levels.
6 months
Number of Participants With Stable Disease
Time Frame: 6 months
Stable disease is defined as having <25% increase in serum IgM levels and <25% reduction in serum IgM levels
6 months
Progression Free Survival
Time Frame: 3 years
Amount of time following loncastuximab administration until >25% increase in serum IgM
3 years
Bone marrow response
Time Frame: 6 months
Absolute change in bone marrow burden of disease from baseline
6 months
Overall Response Rate Among Participants Without MYD88 Mutations
Time Frame: 6 months
Overall Response Rate in participants who tested negative for a MYD88 mutation= Minor response (>25%-50% reduction in serum IgM from baseline) + Partial Response (>50-90% reduction in serum IgM from baseline) + Very Good Partial Response (>90% reduction in serum IgM from baseline) + Complete Response (resolution of all symptoms, normalization of serum IgM with disappearance of IgM paraprotein, resolution of any adenopathy or splenomegaly).
6 months
Overall Response Rate Among Participants Without CXCR4 Mutations
Time Frame: 6 months
Overall Response Rate in participants who tested negative for a CXCR4 mutation= Minor response (>25%-50% reduction in serum IgM from baseline) + Partial Response (>50-90% reduction in serum IgM from baseline) + Very Good Partial Response (>90% reduction in serum IgM from baseline) + Complete Response (resolution of all symptoms, normalization of serum IgM with disappearance of IgM paraprotein, resolution of any adenopathy or splenomegaly).
6 months
Number of Participants With Treatment-related Adverse Events
Time Frame: 6 months
Number of participants who experienced an adverse event while on loncastuximab tesirine
6 months
Number of Participants With IgM Flare
Time Frame: 6 months
Number of participants who experienced an IgM Flare while on loncastuximab tesirine
6 months
Number of Participants With Tumor Lysis Syndrome
Time Frame: 6 months
Number of participants who experienced Tumor Lysis Syndrome while on loncastuximab tesirine
6 months
Impact of loncastuximab tesirine in the participants' quality of life
Time Frame: 6 months
Quality of life questionnaire European Organisation for Research and Treatment of Cancer. Scores range from 0-100 with high scores indicating a better outcome.
6 months
Overall Response Rate Among CXCR4 Mutated Participants
Time Frame: 6 months
Overall Response Rate for participants who tested positive for a CXCR4 mutation= Minor response (>25%-50% reduction in serum IgM from baseline) + Partial Response (>50-90% reduction in serum IgM from baseline) + Very Good Partial Response (>90% reduction in serum IgM from baseline) + Complete Response (resolution of all symptoms, normalization of serum IgM with disappearance of IgM paraprotein, resolution of any adenopathy or splenomegaly).
6 months
Overall Response Rate Among Participants With MYD88 Mutations
Time Frame: 6 months
Overall Response Rate in participants who tested positive for a MYD88 mutation= Minor response (>25%-50% reduction in serum IgM from baseline) + Partial Response (>50-90% reduction in serum IgM from baseline) + Very Good Partial Response (>90% reduction in serum IgM from baseline) + Complete Response (resolution of all symptoms, normalization of serum IgM with disappearance of IgM paraprotein, resolution of any adenopathy or splenomegaly).
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Shayna Sarosiek, MD, Dana-Farber Cancer Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 17, 2022

Primary Completion (Actual)

May 1, 2026

Study Completion (Estimated)

August 1, 2028

Study Registration Dates

First Submitted

December 29, 2021

First Submitted That Met QC Criteria

December 29, 2021

First Posted (Actual)

January 13, 2022

Study Record Updates

Last Update Posted (Actual)

May 20, 2026

Last Update Submitted That Met QC Criteria

May 18, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The Dana-Farber / Harvard Cancer Center encourages and supports the responsible and ethical sharing of data from clinical trials. De-identified participant data from the final research dataset used in the published manuscript may only be shared under the terms of a Data Use Agreement. Requests may be directed to: [contact information for Sponsor Investigator or designee]. The protocol and statistical analysis plan will be made available on Clinicaltrials.gov only as required by federal regulation or as a condition of awards and agreements supporting the research.

IPD Sharing Time Frame

Data can be shared no earlier than 1 year following the date of publication

IPD Sharing Access Criteria

Contact the Belfer Office for Dana-Farber Innovations (BODFI) at innovation@dfci.harvard.edu

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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