A Window of Opportunity Trial: Avelumab in Non-metastatic Muscle Invasive Bladder Cancer

Avelumab is a fully human monoclonal PD-L1 antibody of the immunoglobulin G1 (IgG1) subclass.
It works by binding to PD-L1 on tumor cells, immune cells and/or stromal cells. This prevents
PD-L1 from interacting with PD-1. Inhibition of this interaction increases
activation/survival of antitumor lymphocytes. It also increases innate immunity by resulting
in decreased PD-1 suppression of NK cell function and bolsters antibody production by B cells
due to less PD-L1 binding of PD-1 on B-cells. Additionally, avelumab has been suggested to
have another mechanism involving antibody dependent cellular cytotoxicity (ADCC). ADCC in
these cases involves NK cell recognition and lysis of tumor cells that have antibody bound to
PD-L1. By blocking PD-L1, avelumab leads to less CD80 binding by PD-L1 and more CD80-CD28
binding in response to antigen presentation to T-cells. This results in increased
costimulatory signaling and is another mechanism by which avelumab may enhance T-cell
activation.

Avelumab has been shown to be efficacious across multiple metastatic tumor types, including
urothelial cancer. The phase Ib study has reported survival and safety outcomes with >12
months followup using pooled data on 249 patients with metastatic UC (Apolo et al, ESMO Sept
2017). Patients had been treated with a median of 2 prior therapies in the metastatic setting
and 13 patients who were cisplatin-ineligible were evaluated for safety alone. PD-L1
expression was not a criterion for enrollment. The confirmed objective response rate (ORR)
was 16.1%, with 5% complete responses and 11.2% partial responses. The 6-month
progression-free survival was 27%. The ORR was better than or comparable to chemotherapy in
historical controls. Among responders, 70.3% were maintained > 12 months. Treatment-related
adverse events (AE) occurred in 70%, with 10.7% of the total with AE's of grade >3.
Immune-mediated AE's occurred in 18.5%, of which 4% were grade >3. There is currently a phase
III clinical trial ongoing comparing avelumab to standard of care chemotherapy in the second
line setting or beyond for metastatic UC. Two other checkpoint inhibitors have been approved
in the last 2 years for first line treatment of patients with metastatic UC who are
ineligible for cisplatin-based therapy.

Inclusion Criteria:

- Have undergone TURBT showing newly diagnosed muscle invasive UCB (mixed histology is
allowed if the predominant histology is UCC) within 6 weeks prior to cycle 1, day 1 of
treatment.

- No prior systemic treatment for muscle invasive UCB

- Clinical T2-T4a disease

- No evidence of clinically positive lymph nodes or distant metastasis on computed
tomography (CT) scans of chest and CT or magnetic resonance imaging (MRI) studies of
the abdomen/pelvis. Imaging must be within 90 days of registration.

- Male or female subjects aged ≥ 18 years old.

- Must have adequate kidney, liver, and bone marrow function within 30 days of
registration, as follows:

- Absolute neutrophil count (ANC) ≥ 1.5 × 109/L

- platelet count ≥ 100 × 109/L

- hemoglobin ≥ 9 g/dL (may have been transfused)

- Total bilirubin level ≤ 1.5 × ULN

- AST and ALT levels ≤ 2.5 × ULN

- Estimated creatinine clearance ≥ 30 mL/min according to the Cockcroft-Gault formula

- Negative serum or urine pregnancy test at screening for women of childbearing
potential (WOCBP), within 30 days of registration.

- Both male and female subjects must agree to use highly effective contraception (see
Section 6.1 Table 8) while receiving avelumab and for at least 60 days after last
avelumab treatment if the risk of conception exists.

Female patients must agree to inform study coordinator or investigator immediately if they
think they have become pregnant during the study.

- Must have FFPE tissue available from the TURBT, and patient must consent to the use of
tissue specimens from TURBT and RC for the study.

- Patients must be ineligible for cisplatin-based NAC. Ineligibility criteria include:
creatinine clearance < 60 ml/min by Cockcroft-Gault formula, CTCAE grade ≥ 2 hearing
loss, CTCAE grade ≥ 2 neuropathy, and at discretion of medical oncologist.

- Must be eligible for RC in the opinion of the treating investigator, and willing to
undergo this procedure.

- ECOG performance status (PS) score of 0-2

- Signed informed consent form.

Exclusion Criteria:

Patients must not have any of the following:

- IMMUNOSUPRESSANTS: Current use of immunosuppressive medication or within 4 weeks of
C1D1, EXCEPT for the following: a. intranasal, inhaled, topical steroids, or local
steroid injection (e.g., intra-articular injection); b. Systemic corticosteroids at
physiologic doses ≤ 10 mg/day of prednisone or equivalent; c. Steroids as
premedication for hypersensitivity reactions (e.g., CT scan premedication).

- AUTOIMMUNE DISEASE: Active autoimmune disease that might deteriorate when receiving an
immuno-stimulatory agent. Patients with diabetes type I, vitiligo, psoriasis, or hypo-
or hyperthyroid diseases not requiring immunosuppressive treatment are eligible.
Patients with type I diabetes or hypo- or hyperthyroidism should be on stable doses of
medications for participation.

- ORGAN TRANSPLANTATION: Prior organ transplantation including allogenic stem-cell
transplantation.

- INFECTIONS: Active infection requiring systemic therapy.

- HIV/AIDS: Known history of testing positive for HIV or known acquired immunodeficiency
syndrome.

- HEPATITIS: Hepatitis B virus (HBV) or hepatitis C virus (HCV) infection at screening
(positive HBV surface antigen or HCV RNA if anti-HCV antibody screening test positive)

- VACCINATION: Vaccinate within 4 weeks of the first dose of avelumab and while on study
drug is prohibited except for administration of inactivated vaccines

- HYPERSENSITIIVTY TO STUDY DRUG: Known prior severe hypersensitivity to investigational
product or any component in its formulations, including known severe hypersensitivity
reactions to monoclonal antibodies (NCI CTCAE v4.03 Grade ≥ 3)

- CARDIOVASCULAR DISEASE: Clinically significant (i.e., active) cardiovascular disease:
cerebral vascular accident/stroke (< 6 months prior to enrollment), myocardial
infarction (< 6 months prior to enrollment), unstable angina, congestive heart failure
(≥ New York Heart Association Classification Class II), or serious cardiac arrhythmia
requiring medication.

- Other severe acute or chronic medical conditions including colitis, inflammatory bowel
disease, pneumonitis, pulmonary fibrosis or psychiatric conditions including recent
(within the past year) or active suicidal ideation or behavior; or laboratory
abnormalities that may increase the risk associated with study participation or study
treatment administration or may interfere with the interpretation of study results
and, in the judgment of the investigator, would make the patient inappropriate for
entry into this study.

- Relapsed MIBC (all patients participating in the study should be newly diagnosed)

- Concomitant UCC outside the bladder (e.g., ureter, urethra or renal pelvis)

- Underlying immune disorder (e.g., combined variable immunodeficiency syndrome)

- Erythropoietin receptor agonists within 30 days prior to enrollment.

- G-CSF, GM-CSF or TPO mimetics during the study period or within 3 weeks prior to study
enrollment

- Malignancies other than UCB within 5 years prior to Cycle 1, Day 1, with the exception
of those with low risk of metastasis or death treated with expected curative outcome
(such as, but not limited to, adequately treated carcinoma in situ of the cervix,
basal or squamous cell skin cancer, localized prostate cancer treated with curative
intent and absence of PSA relapse, or ductal carcinoma in situ of the breast treated
surgically with curative intent) or incidental prostate cancer (T1a, Gleason score ≤ 6
and PSA < 0.5 ng/ml)

- Prior immunotherapy with T-cell co-stimulation or checkpoint targeted agents (e.g.,
CTLA-4 inhibitors, anti-PD1 antibodies or anti-PD-L1 antibodies)

- Intravesical chemotherapy or biologic therapy within 6 weeks of Cycle 1, Day 1

- Current participation in another clinical trial for MIBC

- Nursing or pregnant woman

- Uncontrolled cystitis, significant bladder pain or spasms, or gross hematuria that in
the opinion of the principal investigator will preclude study participation

- Major surgical procedures within 4 weeks of registration (other than for diagnosis) or
anticipation that such a procedure will be needed during the study (other than RC)