PV-10 in Combination With Pembrolizumab for Treatment of Metastatic Melanoma

Phase 1b. Up to 24 eligible subjects will be enrolled in an initial cohort in the Phase 1b
portion of the study (Main Cohort). Up to an additional 24 eligible subjects who have failed
to achieve a complete or partial response to or progressed on prior checkpoint inhibition
will be enrolled in a first expansion cohort (Expansion Cohort 1). Up to an additional 24
eligible subjects with Stage III unresectable, in-transit or satellite melanoma will be
enrolled in a second expansion cohort (Expansion Cohort 2). Each subject in each Phase 1b
cohort will receive the combination of IL PV-10 and pembrolizumab.

Phase 2. A total of an estimated 120 eligible subjects will be randomized in a 1:1 ratio to
the two treatment arms (i.e., PV-10 + pembrolizumab or pembrolizumab alone) in the Phase 2
portion of the study. This number of subjects may be modified based on emerging evidence of
preliminary efficacy and effect size from the Phase 1b and initial Phase 2 portions of the
study.

Subjects assigned to receive PV-10 in Phase 1b and 2 will receive initial IL PV-10 to their
injectable lesions commencing on study Day 1 for up to 12 weeks (i.e., investigational
Treatment Phase of the study). PV-10 may be re-administered at 21-day (3-week) intervals
during the Treatment Phase of the study to any remaining, uninjected injectable lesions until
all injectable lesions have been injected. Lesions that fail to exhibit complete ablation may
be re-injected on this schedule.

Pembrolizumab will be administered at 21-day (3-week) intervals per prescribing information
(label) commencing on study Day 1 for up to 24 months or until disease progression, toxicity
requiring discontinuation of study treatment or study termination.

Inclusion Criteria:

1. Age 18 years or older, male or female.

2. Histologically or cytologically confirmed diagnosis of melanoma.

3. Stage IV or Stage III (unresectable, in-transit or satellite) melanoma.

4. At least 1 Injectable Lesion (i.e., cutaneous, subcutaneous, soft tissue, superficial
nodal or palpable nodal lesion with longest diameter at least 5 mm that is suitable
for injection with PV-10).

5. A minimum of 1 measurable Target Lesion that can be accurately measured by calipers,
computed tomography (CT) or magnetic resonance imaging (MRI) consisting of at least
one of the following:

- at least one cutaneous lesion (each lesion ≥ 10 mm longest diameteror up to 5
lesions in aggregate having a sum of longest diameters ≥ 10 mm); and/or

- at least one subcutaneous or soft tissue lesion (each lesion ≥ 10 mm in longest
diameter by CT or MRI); and/or

- at least one nodal lesion (each lesion ≥ 15 mm in short axis diameter by CT or
MRI); and/or

- at least one visceral lesion (each lesion ≥ 10 mm in longest diameter by CT or
MRI).

6. Performance Status: Eastern Cooperative Oncology Group (ECOG) 0-1.

7. Clinical Laboratories:

- absolute neutrophil count (ANC) ≥ 1.5 x 109/L and platelet count ≥100 x 109/L

- estimated creatinine clearance (CrCl, by Cockcroft-Gault formula) or estimated
glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m2

- total bilirubin ≤ 3 times the upper limit of normal (ULN)

- aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase
(ALP) ≤ 5 times the upper limit of normal (ULN)

8. Thyroid function abnormality ≤ Common Toxicity Criteria for Adverse Effects (CTCAE)
Grade 2.

Exclusion Criteria:

1. Untreated or clinically active melanoma brain metastases.

- Subjects with ≤ 3 brain metastases and each ≤ 1 cm size that were treated with
either surgical resection and/or radiation therapy are eligible for study
participation provided (a) there is no evidence of progressive central nervous
system (CNS) disease on brain imaging at least 30 days after definitive treatment
and (b) the subject is not taking prednisone at >10 mg or equivalent daily.

- Subjects with > 1 cm or > 3 in number treated brain metastases are eligible for
study participation provided (a) there is no evidence of progressive CNS disease
on brain imaging at least 90 days after treatment with surgery and/or radiation
therapy and (b) if the subject is not taking prednisone at >10 mg or equivalent
daily.

2. Prior treatment with PV-10 or any checkpoint inhibitor; however, subjects (a) who have
failed to achieve a complete or partial response within 24 weeks following initiation
of checkpoint inhibition or (b) who progressed after more than 12 weeks of checkpoint
inhibition are eligible for study participation in the Phase 1b Expansion Cohort 1
without washout period for checkpoint inhibition.

3. Other prior cancer therapy or anti-cancer vaccine within the lesser of 4 weeks or 5
half-lives before initial study treatment.

4. Known sensitivity to any of the products or components to be administered during
dosing.

5. Concurrent or Intercurrent Illness:

- History or evidence of symptomatic autoimmune pneumonitis, glomerulonephritis,
vasculitis, or other systemic autoimmune disease.

- Evidence of clinically significant immunosuppression.

- Impaired wound healing or other extremity complications due to severe or
uncontrolled diabetes mellitus in subjects whose Injectable Lesions are located
in an extremity.

- Severe peripheral vascular disease (i.e., severe claudication [pain occurring
after less than 200 meters of walking], rest pain, ischemic ulceration or
gangrene) in subjects whose Injectable Lesions are located in an extremity.

- Significant concurrent or intercurrent illness, psychiatric disorders, or alcohol
or chemical dependence that would, in the opinion of the Investigator, compromise
the subject's safety or compliance or interfere with interpretation of study
results.

- Uncontrolled thyroid disease or cystic fibrosis.

- Clinically significant acute or unstable cardiovascular, cerebrovascular
(stroke), renal, gastrointestinal, pulmonary, immunological, endocrine, or
central nervous system disorders.

- Malignancy other than melanoma within 2 years of enrollment except for:
adequately treated (i.e., with curative intent) basal or squamous cell carcinoma,
in situ carcinoma of the cervix, in situ ductal adenocarcinoma of the breast, in
situ prostate cancer, or limited stage bladder cancer.

6. Pregnancy:

- Female subjects who are pregnant or lactating.

- Female subjects who have positive serum pregnancy test taken within 14 days of
initiation of study treatment.

- Female subjects of childbearing potential (defined as having a menstrual cycle
within the past 12 months and not having had a surgical procedure to accomplish
sterilization) who are not using highly effective contraception (e.g., oral
contraceptives, intrauterine devices, double barrier methods such as condoms and
diaphragms, abstinence or equivalent measures).

- Male subjects who are unwilling to use acceptable method of effective
contraception.

7. Subjects unable to comprehend and give informed consent are excluded.