Inclusion Criteria:

          -  Men or women, age 18 years or older

        Part 1:

        • Histology based upon bone marrow biopsies and/or fine needle aspirates as the sole means
        of diagnosis are not acceptable. All subtypes of B-cell NHL may be considered for the
        MT-3724 dose escalation. Presence of lymphadenopathy and/or splenomegaly with
        histopathological evaluation of a lymph node biopsy consistent with CLL.

        Part 2:

          1. Diffuse large B cell lymphoma (DLBCL). Histology based upon bone marrow biopsies
             and/or fine needle aspirates as the sole means of diagnosis are not acceptable.

          2. Subjects must have received at least one anti-CD20 antibody containing regimen that
             resulted in initial measurable response (partial or complete remission), followed by
             relapse/ recurrence.

          3. Life expectancy > 3 months.

          4. Eastern Cooperative Oncology Group (ECOG) performance score of ≤2.

          5. All lymphoma subjects are required to have measurable disease

          6. Patients must be at least 28 days past their last course of lymphoma

          7. Received any amount of anti-CD20 MAb therapy within the following periods before the
             start of treatment

          8. Received any amount of anti-CD20 MAb within the following periods before the start of
             treatment:

               1. Rituximab (Rituxan®): if a subject had received any amount of rituximab within
                  365 days of planned dose day 1 then a serum rituximab level must be negative
                  (<500 ng/ml) at the screening period

               2. Obinutuzumab (Gazyva®): 184 days

               3. Ofatumumab (Arzerra®): 88 days

               4. ibritumomab tiuxetan (Zevalin®): 10 days

          9. Adequate kidney function, assessed by the estimated glomerular filtration rate (eGFR)
             ≥60 mL/min

         10. Female patients of childbearing potential must have a negative serum or urine
             pregnancy test within 3 days prior to initiating dosing. Male and female subjects with
             reproductive potential must agree to use acceptable contraceptive methods until the
             end of study visit.

         11. Patients with known central nervous system metastases may be enrolled if they have
             received radiotherapy, do not require chronic steroid therapy, have had computed
             tomography or magnetic resonance imaging of the brain within 1 month of study entry
             that shows stable disease and they have no neurological symptoms other than low grade
             neuropathy.

        Exclusion Criteria:

          1. History of another cancer other than basal cell carcinoma or cervical intraepithelial
             neoplasia (CIN; i.e., cervical cancer in situ).

          2. Potential subjects cannot have experienced a significant (CTCAE Grade 3 or 4 with or
             without neutropenia) infection within 2 weeks of the first dose of MT-3724.

          3. Ongoing use of any approved or investigational antineoplastic therapies

          4. Systemic corticosteroid therapy at a prednisone dose > 20mg/day (or equivalent) within
             14 days prior to study enrollment

          5. Potential subjects with pre-existing AEs at screening that are severe or life
             threatening by CTCAE, v. 4.03 should not be enrolled.

          6. Patients with uncontrolled or severe cardiovascular disease, including myocardial
             infarct or unstable angina within 6 months prior to start of study treatment, New York
             Heart Association (NYHA) Class II or greater congestive heart failure, serious
             arrhythmias requiring medication for treatment, clinically significant pericardial
             disease, or cardiac amyloidosis may not be enrolled.

          7. Patients with a known history of drug abuse or any chronic neurologic, psychiatric,
             endocrine, metabolic, immunologic, hepatic or renal disease (including a history of
             hemolytic uremic syndrome) that in the opinion of the Investigator would adversely
             affect study participation.

          8. Potential subjects must not have received any vaccines for 28 days prior to
             administration of their first dose of MT-3724 and should not receive any vaccine
             during the study or within 28 days after their last dose of MT-3724. The single
             exception to this exclusion is for the annual influenza (flu) vaccine which can be
             given up to 14 days prior to first dose.

          9. History of hypersensitivity to study drug or to compounds of a similar class, or whose
             past history suggests an increased potential for an adverse hypersensitivity reaction
             to MT-3724 should not be enrolled.

         10. Patients with known active Hepatitis A or C, HIV or a present history of Hepatitis B

         11. Potential subjects who have undergone allogeneic hematopoietic stem cell
             transplantation.

         12. Women who are pregnant or breastfeeding.

         13. Potential subjects who have had major surgery within 6 weeks prior to the first dose
             of study drug or have major surgery planned during the first 12 weeks post MT 3724
             exposure.

        Part 3

        Inclusion Criteria:

          1. Subjects must have relapsed or refractory diffuse large B-cell lymphoma (DLBCL)
             according to the Revised European American Lymphoma/World Health Organization
             (REAL/WHO) classification.

          2. Subjects must have received at least 2 standard of care regimens for NHL treatment.

          3. Subjects must have at least one tumor lesion at screening

          4. Subjects must have life expectancy of >3 months from the start of treatment.

          5. Subjects must have ECOG performance status of 0-2.

          6. Adequate kidney function

          7. QTcF (Fridericia) ≤480 ms determined as the average of three QTcF values from the
             triplicate ECG obtained at screening.

          8. LVEF ≥45% by MUGA or echocardiogram obtained at screening.

          9. Female patients of childbearing potential must not be pregnant.. Male and female
             subjects with reproductive potential must agree to use acceptable contraceptive
             methods until the end of study visit.

         10. Subject must be able to comply with all study-related procedures and medication use.

        Exclusion Criteria:

          1. Received any amount of anti-CD20 MAb within the following periods before the start of
             treatment:

               1. Rituximab (Rituxan®/MabThera® or rituximab biosimilar): if administered within 12
                  to 37 weeks before the start of treatment, then serum rituximab level must be
                  assessed during the screening and confirmed as negative (<500 ng/mL)

               2. Obinutuzumab (Gazyva®/Gazyvaro®): 184 days.

               3. Ofatumumab (Arzerra®): 88 days.

          2. Received approved or investigational treatment for NHL (except anti-CD20 MAb and
             radioimmunoconjugates) within 4 weeks before the start of treatment.
             Radioimmunoconjugates are excluded within 12 weeks before the start of treatment.

          3. Received radiation therapy to target lesions ) within 4 weeks before the start of
             treatment, unless the lesions exhibited objective progression between radiation
             therapy and screening

             a. Palliative radiation therapy to non-target lesions within 4 weeks before the start
             of treatment may be permitted at the investigator's discretion.

          4. Received systemic immunosuppressive agents (except prescribed corticosteroids at doses
             ≤20 mg/day prednisone equivalent) within 2 weeks before the start of treatment

          5. Received any vaccines except injectable flu (inactivated or recombinant) vaccine
             within 4 weeks before the start of treatment, or likely to require any vaccines except
             injectable flu vaccine at any time from the start of treatment until 28 days after the
             last dose of MT-3724.

          6. Received allogeneic stem cell transplant.

          7. Current evidence of CTCAE Grade ≥2 (significant) 1 toxicity before the start of
             treatment, except for hair loss and those significant toxicities permitted in other
             eligibility criteria. Subjects with significant permitted in other eligibility
             criteria. Subjects with significant

          8. History or current evidence of significant infection, systemic infection or wound
             within 2 weeks before the start of treatment.

             a. Subjects with significant infection that has stabilized or improved with oral
             antibiotics before the start of treatment may be eligible at the investigator's
             discretion.

          9. Known or suspected hypersensitivity to the study drug or excipients contained in the
             study drug formulation.

         10. Current evidence of hypersensitivity or other underlying illness requiring systemic
             corticosteroids at doses >20 mg/day prednisone equivalent

         11. Patients with known active Hepatitis C, HIV or a present history of Hepatitis B

         12. Current evidence of incomplete recovery from surgery or radiotherapy at screening, or
             planned surgery or radiotherapy from the start of treatment until the short term
             follow-up visit, except minor elective surgery or palliative radiation therapy to
             non-target lesions deemed acceptable by the investigator.

         13. History of cardiovascular, renal, hepatic or any other disease within ≤3 months before
             the start of treatment

         14. History of another primary malignancy within the past 3 years (except for ductal
             breast cancer in situ, non-melanoma skin cancer, prostate cancer not requiring
             treatment, and cervical carcinoma in situ) that required systemic drug therapy or
             radiotherapy.

         15. Current evidence of new or growing brain or spinal metastases during screening.

         16. Women who are pregnant or breastfeeding.

         17. History of non-adherence to the schedule of procedures or medication use