Study of Pembrolizumab (MK-3475) in Combination With Romidepsin

Study Groups:

If you are found to be eligible to take part in this study, you will be assigned to a study
group based on when you join this study. Up to 3 groups of up to 6 participants will be
enrolled in Phase 1 of the study, and up to 21 participants will be enrolled in Phase 2.

If you are enrolled in Phase 1, the dose of romidepsin you receive will depend on when you
join this study. The first group of participants will receive the highest dose level of
romidepsin. A second group will receive a lower dose of romidepsin than the group before it,
if intolerable side effects are seen. A third group will receive an even lower dose if there
are still intolerable side effects.

If you are enrolled in Phase 2, you will receive romidepsin at the highest dose that was
tolerated in Phase 1.

All participants will receive the same dose level of pembrolizumab.

Study Drug Administration:

You will receive the study drugs in 21-day study cycles. On Day 1 of each cycle, romidepsin
will be given first, followed by pembrolizumab. Romidepsin will be given by vein over about 4
hours on Days 1 and 8 of every cycle. You will receive pembrolizumab by vein over about 30
minutes after romidepsin on Day 1 of each cycle.

If you are in Phase 2, you will not receive romidepsin on Day 1 of Cycle 1.

Length of Study:

You may continue taking the study drugs for up to 36 cycles, as long as the doctor thinks it
is in your best interest. You will no longer be able to take the study drug if the disease
gets worse, if intolerable side effects occur, or if you are unable to follow study
directions.

Your participation on the study will be over after the follow-up visits.

Study Visits:

You will have study visits on Days 1 and 8 of Cycle 1. You will then have study visits on
Days 1 and 8 of Cycles 2 and 3. After that, you will only have study visits on Day 1 of
Cycles 4 and beyond. At each of these visits:

- You will have a physical exam.

- Blood (1 tablespoon) will be drawn for routine tests.

- On Day 1 of Cycle 1 and within 72 hours before Day 1 of each cycle, if you can become
pregnant, part of the above routine blood sample or urine will be collected for a
pregnancy test. To take part in this study, you must not be pregnant.

At some of these visits, additional tests will be performed:

- On Day 1 of every cycle that you receive romidepsin, you will have an EKG within 6 hours
before you receive romidepsin.

- On Day 1 of Cycles 1-3, Day 8 of Cycles 1 and 2, and Day 15 of Cycle 1, blood (about 1
teaspoon) will be drawn for research tests.

- On Day 1 of Cycle 2 and every 2 cycles after that, blood (about 1 tablespoon) will be
drawn for thyroid function tests.

- On Day 1 of Cycle 4 and every 3 cycles after that, you will have the same imaging scans
(such as CTs or PET/CTs) you had at screening to check the status of the disease.

End-of-Dosing Visits:

When you stop receiving the study drugs, blood (about 1 tablespoon) will be drawn for routine
tests and thyroid function tests. You will have these blood tests again 30 days later.

Follow-Up:

Every 12 weeks after the second end-of-dosing visit:

- Blood (about 1 tablespoon) will be drawn for routine tests and thyroid function tests.

- You will have the same imaging scans (such as CTs or PET/CTs) you had at screening to
check the status of the disease.

You will also be called every 12 weeks to be asked about your health. This call should last
about 15 minutes.

Inclusion Criteria:

1. Patients with peripheral T-cell lymphoma (including but not limited to PTCL-NOS,
antioimmunoblastic T-cell lymphoma, anaplastic large T-cell lymphoma). Patients with
mycosis fungoides with large cell transformation with measurable disease is eligible.

2. Disease status defined as refractory to or relapsed after >/=1 prior treatment lines.

3. Subjects with ALK+ ALCL should have been treated with, be ineligible for, or have
refused chemotherapy and brentuximab prior to enrollment on the current study.

4. Patients with a measurable disease, defined by a node or mass with the longest
diameter >/= 1.5cm

5. Be willing and able to provide written informed consent/assent for the trial.

6. Be >/= 18 years of age on day of signing informed consent.

7. Patients with PTCL should have radiographically measurable disease >/= 1.5cm.

8. Be willing to provide tissue from a newly obtained core or excisional biopsy of a
tumor lesion. Newly-obtained is defined as a specimen obtained up to 6 weeks (42 days)
prior to initiation of treatment on Day 1. Subjects for whom newly-obtained samples
cannot be provided (e.g. inaccessible or subject safety concern) may submit an
archived specimen.

9. Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG)
Performance Scale.

10. Demonstrate adequate organ function: Absolute neutrophil count (ANC) >/=1,500 /mcL;
Platelets >/= 100,000 / mcL; Hemoglobin >/=9 g/dL or >/=5.6 mmol/L without transfusion
or erythropoietin (EPO) dependency (within 7 days of assessment); Serum creatinine OR
Measured or calculated creatinine clearance Glomerular filtration rate (GFR) can also
be used in place of creatinine or creatinine clearance (CrCl) normal (ULN) OR >/= 60 mL/min for subject with creatinine levels > 1.5 X institutional
ULN; Serum total bilirubin total bilirubin levels > 1.5 ULN; AST (SGOT) and ALT (SGPT) ULN for subjects with liver metastases; Albumin >/=2.5 mg/dL;

11. Continuation 9) International Normalized Ratio (INR) or Prothrombin Time (PT) ULN unless subject is receiving anticoagulant therapy as long as PT or Partial
thromboplastin time (PTT) is within therapeutic range of intended use of
anticoagulants; Activated Partial Thromboplastin Time (aPTT)anticoagulant therapy, as long as PT or PTT is within
therapeutic range of intended use of anticoagulants; a) Creatinine clearance should be
calculated per institutional standard.

12. Female subject of childbearing potential should have a negative urine or serum
pregnancy within 72 hours prior to receiving the first dose of study medication. If
the urine test is positive or cannot be confirmed as negative, a serum pregnancy test
will be required.

13. Female subjects of childbearing potential must be willing to use an adequate method of
contraception, for the course of the study through 120 days after the last dose of
study medication.

14. Note: Abstinence is acceptable if this is the usual lifestyle and preferred
contraception for the subject.

15. Male subjects of childbearing potential must agree to use an adequate method of
contraception, starting with the first dose of study therapy through 120 days after
the last dose of study therapy. Note: Abstinence is acceptable if this is the usual
lifestyle and preferred contraception for the subject.

Exclusion Criteria:

1. Is currently participating and receiving study therapy or has participated in a study
of an investigational agent and received study therapy or used an investigational
device within 4 weeks of the first dose of treatment.

2. Has a diagnosis of immunodeficiency, is receiving systemic steroids above physiologic
dose (>10mg/day prednisone or equivalent) within 7 days of start of therapy or is
receiving any other fomr of immunosuppressive therapy.

3. Has a known history of active TB (Bacillus Tuberculosis)

4. Hypersensitivity to pembrolizumab or any of its excipients.

5. Has had a prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to study
Day 1 or who has not recovered (i.e., due to agents administered more than 4 weeks earlier.

6. Has had prior chemotherapy, targeted small molecule therapy, or radiation therapy
within 2 weeks prior to study Day 1 or who has not recovered (i.e., baseline) from adverse events due to a previously administered agent. Note: Subjects
with study. Note: If subject received major surgery, they must have recovered adequately
from the toxicity and/or complications from the intervention prior to starting
therapy.

7. Has a known additional malignancy that is progressing or requires active treatment.
Exceptions include basal cell carcinoma of the skin or squamous cell carcinoma of the
skin that has undergone potentially curative therapy or in situ cervical cancer.

8. Has known active central nervous system (CNS) metastases and/or carcinomatous
meningitis. Subjects with previously treated brain metastases may participate provided
they are stable (without evidence of progression by imaging for at least four weeks
prior to the first dose of trial treatment and any neurologic symptoms have returned
to baseline), have no evidence of new or enlarging brain metastases, and are not using
steroids for at least 7 days prior to trial treatment. This exception does not include
carcinomatous meningitis which is excluded regardless of clinical stability.

9. Has active autoimmune disease that has required systemic treatment in the past 2 years
(i.e. with use of disease modifying agents, corticosteroids or immunosuppressive
drugs). Replacement therapy (eg., thyroxine, insulin, or physiologic corticosteroid
replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a
form of systemic treatment.

10. Has known history of non-infectious pneumonitis that required systemic steroid use, or
has active pneumonitis.

11. Has an active infection requiring systemic therapy.

12. Has a history or current evidence of any condition, therapy, or laboratory abnormality
that might confound the results of the trial, interfere with the subject's
participation for the full duration of the trial, or is not in the best interest of
the subject to participate, in the opinion of the treating investigator.

13. Has known psychiatric or substance abuse disorders that would interfere with
cooperation with the requirements of the trial.

14. Is pregnant or breastfeeding, or expecting to conceive or father children within the
projected duration of the trial, starting with the pre-screening or screening visit
through 120 days after the last dose of trial treatment.

15. Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent.

16. Has a known history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies).

17. Has known active Hepatitis B (e.g., HBsAg reactive) or Hepatitis C (e.g., HCV RNA
[qualitative] is detected).

18. Baseline electrocardiogram (EKG) shows QTcF > 470 msec

19. Concomitant use of strong CYP3A4 inhibitors and inducers.

20. Has received a live vaccine within 30 days of planned start of study therapy. Note:
Seasonal influenza vaccines for injection are generally inactivated flu vaccines and
are allowed; however intranasal influenza vaccines (e.g., Flu-Mist®) are live
attenuated vaccines, and are not allowed.

21. Has undergone prior allogeneic hematopoietic stem cell transplantation within the last
5 years. (Subjects who have had a transplant greater than 5 years ago are eligible as
long as there are no symptoms of Graft versus Host Disease (GVHD).