Safety, Tolerability and Pharmacokinetics of MRG-106 in Patients With Mycosis Fungoides (MF), CLL, DLBCL or ATLL

Study Design:

- Part A: Cohorts of 3-6 patients diagnosed with MF will receive up to five intratumoral
injections of cobomarsen over a period of up to 15 days with follow-up for an additional
20 days, beginning with the maximum deliverable intratumoral dose. Doses may be
decreased in subsequent cohorts to determine the minimum pharmacodynamically active
dose.

- Parts B-F: Patients in these parts of the study will be diagnosed with MF (Parts B and
C), CLL (Part D), DLBCL (Part E), or ATLL (Part F). All patients will receive
subcutaneous or intravenous cobomarsen (or a combination of systemic and intratumoral
administration for MF patients only) on Days 1, 3 and 5, and will continue dosing on a
weekly schedule until the patient becomes intolerant, develops clinically significant
side effects, progresses, or the trial is terminated. Doses administered will not exceed
a dose level predicted to be safe based on all prior treatment experience with the drug.
Patients in Part B may continue on a stable background therapy for their disease during
their treatment with cobomarsen, while patients in Parts C-F will be treated with
cobomarsen alone.

Inclusion Criteria:

- Parts A-C only: Patients must have biopsy proven MF, clinical stage I, II, or III
(excluding visceral or nodal involvement), and must be refractory to or intolerant of
established therapies for their condition

- Part D only: Patients diagnosed with CLL who are intolerant to, or have disease that
is relapsed/refractory after, at least two prior therapies

- Part E only: Patients with biopsy-proven DLBCL who are intolerant to, or have disease
that is relapsed/refractory after, at least two prior therapies, including any
anti-CD20 monoclonal antibody and chemotherapy with curative intent

- Part F only: Patients with documented HTLV-1 infection and histologically or
cytologically proven ATLL of any stage, and who are intolerant to, or have disease
that is relapsed/refractory after, at least one prior therapy

- Females must not be pregnant or lactating. Women of child-bearing potential must use a
highly effective method of contraception throughout their study participation and for
at least 6 months following the last dose of study drug.

- Males must be surgically sterile, abstinent, or if engaged in sexual relations with a
female of child-bearing potential, must be willing to use a highly effective method of
contraception throughout their study participation and for at least 6 months after the
last dose of study drug.

Exclusion Criteria:

- Evidence of renal or liver dysfunction at screening

- Clinically significant anemia, neutropenia or thrombocytopenia at screening

- History of bleeding diathesis or coagulopathy

- Clinically significant cardiovascular disease, history of myocardial infarction within
the last 6 months, or evidence of QTc interval prolongation at screening

- Serologically positive for HIV; serologically positive for Hepatitis B or Hepatitis C
with evidence of liver dysfunction or documented liver cirrhosis

- Prior malignancies within the past 3 years (with allowance for adequately treated in
situ carcinoma of the cervix uteri, and basal cell or localized squamous cell
carcinoma of the skin treated with curative intent)

- Use of an investigational small molecule drug during the 30 days prior to screening or
use of an investigational oligonucleotide or biologic drug during the prior 90 days