Denosumab + Pembrolizumab in Patients With Stage IV Melanoma

STUDY OBJECTIVES

Co-primary Objectives

- Assess the mechanistic (immune-mediated and/or direct antitumor effect) and
pharmacodynamics effect (tissue saturation studies) of denosumab alone (i.e., after two
loading doses of denosumab are given on day 1 and day 8) in patients with unresectable
stage III or distant metastatic PD-1/PD-L1 inhibitor-naïve cutaneous melanoma (stage
III/IV) by performing translational research on peripheral blood and tumor biopsy
samples collected at baseline and on day 20+or-2 (week 4) of the study.

- Assess the immune-mediated and direct antitumor effect of denosumab in combination with
pembrolizumab in patients with unresectable stage III or distant metastatic PD-1/PD-L1
inhibitor-naïve cutaneous melanoma (AJCC stage III/IV) by performing translational
research on peripheral blood and tumor biopsy samples collected at weeks 16, 28 and 40
of the study and comparing the results with those from baseline and day 20+or-2 ( week
4, denosumab alone).

Secondary Objectives

- Assess the safety of the denosumab-pembrolizumab combination in unresectable stage III
or distant metastatic PD-1/PD-L1 inhibitor-naïve cutaneous melanoma (AJCC stage III/IV)
by NCI-CTCAE v.5.0.

- Determine antitumor response by RECIST v1.1 criteria of the denosumab-pembrolizumab
combination at 16 weeks in patients with unresectable stage III or distant metastatic
PD-1/PD-L1 inhibitor-naïve cutaneous melanoma (AJCC stage III/IV).

- Determine the 1-year OS rate of the pembrolizumab-denosumab combination in patients with
unresectable stage III or distant metastatic PD-1/PD-L1 inhibitor-naïve cutaneous
melanoma (AJCC stage III/IV).

- Determine the 6-month PFS rate of the denosumab-pembrolizumab combination in patients
with unresectable stage III or distant metastatic PD-1/PD-L1 inhibitor-naive cutaneous
melanoma (AJCC stage III/IV).

Endpoints Co-primary Endpoints

- The immune-mediated mechanism of action of denosumab alone will be evaluated in blood
and tumor samples collected at baseline and on day 20+or- 2 (Week 4) of the study.
Multiparameter flow cytometry and ELISA assays will be performed on peripheral
blood/serum samples as outlined above in section 1.10.1 Tumor biopsy samples will be
evaluated by IHC and IF studies as outlined above in section 1.10.2 (See referenced
sections for assay details. The investigators will estimate differences after 3 weeks of
denosumab treatment versus baseline).

- The immune-mediated mechanism of action of denosumab combined with pembrolizumab will be
evaluated in blood and tumor samples collected at weeks 16, 28 and 40 of the study.
Multi-parameter flow cytometry and ELISA assays will be performed on peripheral
blood/serum samples collected at weeks 16, 28 and 40 as outlined above in section
1.10.1. Tumor biopsy samples obtained at week 16 will be evaluated by IHC and IF studies
as outlined above in section 1.10.2 (See referenced sections for assay details. The
investigators will describe differences in immunomodulatory/antitumor effects observed
with denosumab therapy with later immunomodulatory/antitumor effects observed after the
addition of pembrolizumab to denosumab).

Secondary Endpoints

- AEs experienced by patients receiving denosumab-pembrolizumab will be assessed per
NCI-CTCAE v.5.0.

- The overall RR (CR + PR) at 16 weeks will assessed based on RECIST v1.1 criteria.

- Overall Survival (OS) rate at 1-year is defined as the time from day 1 of study
treatment until death as a result of any cause within one year of initiating study
treatment.

- Progression Free Survival (PFS) rate at 6 months is defined as the time from day 1 of
treatment until disease progression or death status measured 6 months after initiating
study treatment. Progression events will be defined per RECIST v1.1 criteria.

Procedures

Subjects in this trial will be given denosumab, 120 mg s.c. q4 weeks, starting on day 1 of
study treatment. An additional loading dose of denosumab will be administered on day 8.
Pembrolizumab, 200 mg will be administered intravenously (IV) every 3 weeks and initiated 21
days after the first dose of denosumab is given. Combination therapy with both agents will
continue as long as subjects benefit from therapy for up to 1 year. Study therapy will be
discontinued for intolerable toxicity, disease progression or for other reasons at the
discretion of the investigator. If subjects are not withdrawn prematurely then their last
dose of study medications will be administered approximately 49 weeks after denosumab was
initiated.

Inclusion Criteria:

1. Signed written informed consent and HIPAA authorization for release of personal health
information.

2. Age ≥ 18 years at the time of consent.

3. Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-2.

4. Histologically confirmed melanoma of cutaneous primary; metastatic melanoma from
unknown primary are allowed because melanoma of unknown primary is biologically
similar to cutaneous melanomas.

5. AJCC stage III/IV unresectable disease. Both should be measurable by RECIST v1.1
criteria.

6. Must have available and consent to collect archived tumor blocks from previous
surgeries confirming or treating metastatic disease (e.g. radical lymph node
dissection); if not available or of insufficient quantity (e.g. < 2-mm2 size tumor) or
quality (> 50% necrosis, < 30% tumor cells) they can be enrolled into the trial, if
they consent to have a tumor biopsy before treatment initiation.

7. Must agree to undergo one on-treatment biopsy on week 4of the study; the biopsy at
week 16 is optional.

8. Must agree to have 100 mL blood drawn for study purposes on week 1 , day 20+or-2 (week
4), week 16, week 28, week 40 and end of treatment.

9. Demonstrate adequate organ function, as defined in the table; all screening labs to be
obtained within 72 hours prior to registration.

10. Females of childbearing potential must have a negative serum pregnancy test within 72
hours prior to study treatment. Note: Females are considered of child bearing
potential unless they are surgically sterile (have undergone a hysterectomy, bilateral
tubal ligation, or bilateral oophorectomy) or they are naturally postmenopausal for at
least 12 consecutive months.

11. Females of childbearing potential must be willing to use adequate method of
contraception, as outlined in Section 4.5.2 - Oral contraception is required 14 days
prior to initiation of study medications until 120 days after treatment
discontinuation. Note: Abstinence is acceptable if this is the usual lifestyle and
preferred contraception for the subject.

12. Male patients with female partners must have had a prior vasectomy or agree to use an
adequate method of contraception as outlined in Section 4.5.2 - 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.

13. As determined by the enrolling physician or protocol designee, willingness and ability
of the subject to understand and comply with study procedures.

14. Previous radiation therapy is allowed, provided it is completed ≥14 days prior to
starting denosumab and patient has recovered adequately from any related toxicities
(grade≤1).

15. If patient has received adjuvant treatments, in particular ipilimumab and high dose
interferon, any toxicities must have resolved to grade 1 or less. Grade 2 toxicities
attributed to ipilimumab from autoimmune endocrinopathies that require permanent
hormone replacement therapy are allowed as long as they are adequately treated. This
implies that patients should be off systemic steroids for treatment of any of these or
other autoimmune toxicities (e.g. colitis, rash).

Exclusion Criteria:

1. History of prior malignancy, with the exception of the following:

- Non-melanoma skin cancers, non-invasive bladder cancer, and carcinoma in situ of
the cervix,

- Prior history of prostate, provided that patient is not under active systemic
treatment other than hormonal therapy and with documented undetectable prostate
specific antigen (PSA < 0.2 ng/mL),

- Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) provided
patient has isolated lymphocytosis (Rai stage O), and does not require systemic
treatment [for "B" symptoms, Richter's transformation, lymphocyte doubling time
(< 6 months), lymphadenopathy or hepatosplenomegaly],

- Lymphoma or any type or hairy-cell leukemia, provided patient is not on an active
systemic treatment and is in complete remission, as evidenced by Positron
Emission Tomography (PET)/CT scans and bone marrow biopsies for at least 3
months,

- History of malignancy, provided patient has completed therapy and is free of
disease for ≥ 2 years. If patient has had other malignancy within the last 2
years from which he/she may have been completely cured by surgery alone, he/she
may considered to be enrolled on condition that the risk of development of
distant metastatic disease based on the American Joint Committee in Cancer (AJCC)
staging system is less than 30%.

2. Has known active central nervous system (CNS) metastases that are symptomatic and
require antiepileptic drugs or corticosteroids. Patients with carcinomatous meningitis
are also excluded. Subjects with previously treated brain metastases may participate
provided they are stable (without evidence of progression by imaging) for at least 2
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. Patients with leptomeningeal disease are excluded.

3. Treatment with any investigational drug, immunotherapy or chemotherapy within 28 days
prior to study treatment (i.e., initiation of denosumab). Treatment with any targeted
therapy (e.g. Mitogen-Activated Protein Kinases (MAPK) inhibitors) is allowed as long
as at least 15 days have elapsed since last dose of drug.

4. Patients discontinuing prior therapy with tyrosine kinase inhibitors for melanoma
should be off these medications for at least 15 days before starting study treatment.

5. Prior PD-1/PD-L1 therapies in the adjuvant setting; targeted therapies or prior
ipilimumab in the adjuvant setting are allowed.

6. Any condition, including laboratory abnormalities, that in the opinion of the
investigator places the subject at unacceptable risk, if he/she were to participate in
the study. This includes, but is not limited, to serious medical conditions or
psychiatric illness likely to interfere with participation in this clinical study.

7. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy
equivalent to daily doses of prednisone of 10 mg or greater (or an equivalent dose of
other corticosteroids) or any other form of immunosuppressive therapy within 7 days
prior to the first dose of trial treatment.

8. Has a known history of active tuberculosis (Bacillus Tuberculosis).

9. 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.

10. Hypersensitivity to pembrolizumab or denosumab or any of their excipients.

11. 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 (e.g., thyroxine, insulin, or physiologic corticosteroid
replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a
form of systemic treatment.

12. Has a history of non-infectious pneumonitis that required steroids or evidence of
interstitial lung disease or current active, non-infectious pneumonitis. Episodic,
brief (< 7 day) exposure to systemic corticosteroids (e.g. steroid taper for poison
ivy or Chronic Obstructive Pulmonary Disease (COPD) exacerbation) is allowed.

13. Has a history of an acute coronary event (e.g. myocardial infarction) within 6 months
since study entry, uncontrolled and symptomatic coronary artery disease, or congestive
heart failure New York Heart Association class III/IV.

14. Has an active infection requiring systemic therapy within 7 days prior to treatment
initiation.

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

16. Known serologic status reflecting active hepatitis B or C infection. Patients that are
hepatitis B core antibody positive, but antigen negative, will need a negative
polymerase chain reaction (PCR) prior to enrollment. [Note: Hepatitis B antigen or PCR
positive patients will be excluded].

17. 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.

18. Known active metabolic bone disease such as Paget's disease, Cushing's disease,
hyperprolactinemia, over the last year 12 months, known history of osteoporosis that
is symptomatic (e.g. history of fractures, bone pain), or hypercalcemia/hypocalcemia
of any type (serum free calcium being more than 1.1 x upper limit of normal (ULN) and
less than 0.9 x, lower limits normal. LLN) over the last 2 weeks since study
initiation that requires treatment beyond calcium and vitamin D supplementation.

19. Prior treatment with denosumab. Use of bisphosphonates for treatment of metastatic
bone disease, but not for hypercalcemia of malignancy, is allowed.

20. History of current evidence of osteonecrosis or osteomyelitis of the jaw, active
dental or jaw problems necessitating known invasive dental procedure during the study,
or non-healed dental or oral surgery. Note: Patient should be referred to dentist
before study treatment initiation for poor dentition or other dental issues that, in
the opinion of the treating physician, may increase the risk of osteonecrosis of the
jaw.