PVSRIPO for Recurrent Glioblastoma (GBM)

PVSRIPO is a genetically recombinant, non-pathogenic poliovirus:rhinovirus chimera with a
tumor-specific conditional replication phenotype. It consists of the genome of the live
attenuated poliovirus serotype 1 (SABIN) vaccine (PV1S) with its cognate internal ribosomal
entry site (IRES) element replaced with that of human rhinovirus type 2 (HRV2). PVSRIPO has
been manufactured at NCI-Frederick, NCI, NIH.

Catheter Implantation: PVSRIPO will be delivered directly into the tumor. A stereotactic
biopsy will be performed prior to virus administration for frozen section confirmation of
viable tumor and further analysis. The biopsy needle will be placed with stereotactic
guidance by a Cosman-Robert-Wells, MRI-compatible, stereotactic head frame or similar
frameless device. Immediately following the stereotactically-guided tumor biopsy, a catheter
will be implanted in the operating room (OR) at a site the same or different from that used
for the biopsy using sterile techniques. A CT may be used to confirm catheter placement
post-operatively.

Agent infusion: The entire volume of the agent to be delivered will be pre-loaded into a
syringe by the investigational pharmacist and connected to the catheter under sterile
conditions in the Neuro-Surgical Intensive Care Unit (NSICU) or neuro step down unit just
prior to the beginning of infusion. Drug infusion will occur in the NSICU or neuro step down
unit so that all other emergency facilities will be available. Patients will be infused
through a Medfusion 3500 or 3010 infusion pump pre-programmed to a delivery rate of 500
microliters/hour. The total amount of the inoculum delivered to the patient will be 3 ml. The
virus injection procedure will be completed within 6.5 hours. The catheter will be removed
following the post-PVSRIPO infusion MRI.

Biopsy sampling and analyses: Biopsy material will be obtained from tumor tissue prior to
virus administration. This tissue material will be subjected to routine histology to confirm
tumor recurrence by the study neuropathologist, Dr. R. McLendon or his designate. Molecular
genetic tests will also be conducted on extracts of tumor cells from the protocol-specified
biopsy prior to PVSRIPO infusion. After acquiring sufficient tissue for standard clinical
pathologic testing, up to three additional core biopsies will be obtained, if possible. The
additional core biopsies will be used for genetic analysis, including full genome or full
exome sequencing, as well as other molecular genetic testing. This testing will include, but
is not limited to, DNA sequencing, gene amplification, and gene expression. Additional
pathology tests on the protocol-specified biopsy tissue may be included, if a sufficient
amount of tissue remains after standard clinical pathologic testing.

Selected patients who benefited from the initial infusion of PVSRIPO within this protocol
will be eligible for a second infusion. All procedures previously described will be followed;
however, the addition of a single dose of lomustine 8 weeks after PVSRIPO administration will
alter the schedule of events that was previously described.

During the dose escalation phase of the study, the starting amount (dose level 1) of PVSRIPO
to be delivered was 1.0 x 10^8 tissue culture infectious dose (TCID50). Dose level 2 was 3.3
x 10^8 TCID50, dose level 3 was 1.0 x 10^9 TCID50, dose level 4 was 3.3 x 10^9 TCID50, and
dose level 5 wase 1.0 x 10^10 TCID50. 50% Tissue Culture Infective Dose (TCID50) is the unit
of measure of infectious virus titer.

To minimize the number of patients treated at low-dose levels during the dose escalation
phase, we used a two-step continual reassessment method (CRM) design that included an
escalation step and a model-guided step. In the dose escalation phase, dose levels were
rapidly escalated as preclinical data suggested that dose-limiting toxicity (DLT) would not
occur at any of the five dose levels that were being evaluated. Decisions concerning dose
escalation for subsequent patients were based upon the occurrence of DLT during the first 4
weeks after treatment administration. Initially, each patient was observed for ≥ 4 weeks
before the next patient was treated. Starting at dose level 1, one patient was to be treated
at each higher dose level. If no DLT was observed within 4 weeks of administration, then the
next patient was to be treated at the next higher dose. If no DLTs were observed among
patients treated on the first four dose levels, subsequent patients were to be treated at
dose level 5. The escalation step was to be interrupted if a patient assigned to one of the
first 4 dose levels or more than 20% of patients treated at dose level 5 experienced a DLT.
In that case, further dose escalation or de-escalation would be guided by the
likelihood-based implementation of the CRM, in which the one-parameter hyperbolic tangent
model would be used to estimate the probability of DLT at each of the 5 dose levels based
upon available data. The highest dose level for which this estimated probability is less than
20% would be identified as the maximum tolerated dose (MTD).

After completion of the dose escalation phase and determination of the MTD, the study
protocol was amended to allow continued patient accrual to a dose expansion phase, in order
to aid in the determination of the Recommended Phase II Dose (RP2D), and to garner more
information about patient safety. The RP2D of PVSRIPO is the safe, therapeutic dose where
patients have not experienced undue side effects from PVSRIPO or from the management of
cerebral inflammation secondary to PVSRIPO administration. To address difficulties tapering
patients off of steriods, the dose was reduced to dose level 2 (3.3 x 10^8 TCID50) for the
dose expansion phase. After 6 patients were treated at dose level 2 in the dose expansion
phase, due to continued difficulties tapering patients off steroids, the protocol was amended
to further reduce the dose to dose level -1 (5.0 x 10^7 TCID50) with the goal of limiting the
occurrence of known possible side effects of prolonged steroid use in patients who otherwise
benefit from this investigational therapy. After the treatment of 24 patients at dose level
-1, despite the fact that these patients were able to remain off significant doses of
steroids, the patients benefiting the most from PVSRIPO appeared to be those who had
experienced minimal or easily controllable inflammation. Hence, the protocol was amended to
reduce the PVSRIPO dose to dose level -2 (1.0 x 10^7 TCID50) with the goal of limiting the
occurrence of undesirable burden from inflammation and its treatment on as many subjects (and
caregivers) as possible. Based upon additional animal studies, dose level -2 (1.0 x 10^7
TCID50) would also be a therapeutic dose. Reduction to dose level -2 was not due to concerns
for the safety of the patients on dose level -1, but due to the observation that less
inflammatory reaction appeared to be a predictor of better survival and treatment response.
After treating 15 patients at dose level -2, based upon pre-clinical and clinical data
collected on dose levels -1 and -2, there was no evidence of pre-clinically or clinically
important differences between these dose levels. Therefore, the decision was made to treat
all future study patients at dose level -1 (5.0 x 10^7 TCID50).

Inclusion Criteria:

1. Disease Status. Patients must have a recurrent supratentorial WHO Grade IV malignant
glioma based on imaging studies with measurable disease (≥ 1 cm or ≤ 5.5 cm of
contrast-enhancing tumor). Prior histopathology consistent with a World Health
Organization (WHO) Grade IV malignant glioma confirmed by the study pathologist, Roger
McLendon, or his designate.

2. Age. Due to the potential implications of the treatment on the developing CNS, all
patients must be ≥ 18 years of age at the time of entry into the study.

3. Performance Status. The patient must have a Karnofsky Performance Score (KPS) of ≥ 70%
at the time of entry.

4. Laboratory Studies

- Platelet count ≥ 125,000/microliter prior to biopsy. Platelets ≥
100,000/microliter prior to infusion

- Prothrombin and Partial Thromboplastin Times ≤ 1.2 x normal prior to biopsy

- Positive serum anti-poliovirus titer prior to biopsy (except for retreatment)

- Creatinine ≤ 1.2 x normal prior to biopsy

- Total bilirubin, SGOT, SGPT, alkaline phosphatase ≤ 2.5 x normal prior to biopsy

- Neutrophil count ≥ 1000 prior to biopsy

- Hemoglobin ≥ 9 prior to biopsy

5. Poliovirus Immunization Booster. The subject must have received a boost immunization
with trivalent inactivated IPOL™ (Sanofi-Pasteur) at least 1 week prior to
administration of the study agent.

6. Disease Confirmation. At the time of biopsy, prior to administration of virus, the
presence of recurrent tumor must be confirmed by histopathological analysis.

7. Informed Consent. A signed informed consent form approved by the Duke University
Institutional Review Board (IRB) will be required for patient enrollment into the
study. Patients must be able to read and understand the informed consent document and
must sign the informed consent indicating that they are aware of the investigational
nature of this study.

8. Brain MRI. Able to undergo brain MRI with and without contrast

Exclusion Criteria:

1. Pregnancy. Because of the unknown risk of virus administration potentially affecting a
developing fetus or growing infant, females who are pregnant or breast-feeding during
the study period will be excluded. Adults of reproductive potential not employing an
effective method of birth control will be excluded. Sexually active women of child
bearing potential, whose partner is male, must use medically accepted birth control.
Sexually active men, whose partner is a female of child bearing potential, must use a
medically accepted birth control.

2. Disease Status. Because patients will receive drug intracerebrally, patients with an
impending, life-threatening cerebral herniation syndrome, based on the assessment of
the study neurosurgeons, Allan Friedman, John Sampson, or Peter Fecci, or their
designate, will be excluded.

3. Medical Conditions. Because the potential toxicities from the agent being studied in
this protocol may be similar to some known diseases or may be more dangerous in the
context of certain known diseases, the following patients will be excluded to avoid
confounding the study results:

- Patients with an active infection requiring intravenous treatment or having an
unexplained febrile illness (Tmax > 99.5 F/37.5 C).

- Patients with known immunosuppressive disease or known human immunodeficiency
virus infection.

- Unstable or severe intercurrent medical conditions such as severe heart (New York
Heart Association Class 3 or 4) or known lung (FEV1 < 50%) disease, uncontrolled
diabetes mellitus.

- Albumin allergy. Albumin is added to the agent as a stabilizer. Patients with a
known allergy will be excluded.

- Gadolinium allergy. Gadolinium is used as contrast for the MRI.

4. Previous Poliomyelitis. A history of neurological complications due to poliovirus
infection would imply previous virus replication in the CNS. Based on animal studies,
previous exposure to poliovirus administered intracerebrally can reduce subsequent
virus replication in the CNS.

5. Prior Therapy. Patients who have not recovered from the toxic effects of prior
chemotherapy and/or radiation therapy will be excluded. Guidelines for this recovery
period are dependent upon the specific therapeutic agent being used:

- Patients may not have received chemotherapy or bevacizumab ≤ 4 weeks [except for
nitrosourea (6 weeks) or metronomic dosed chemotherapy such as daily etoposide or
cyclophosphamide (1 week)] prior to starting the study drug unless patients have
recovered from side effects of such therapy.

- Patients may not have received immunotherapy ≤ 4 weeks prior to starting the
study drug unless patients have recovered from side effects of such therapy.

- Patients may not be less than 12 weeks from radiation therapy, unless progressive
d disease outside of the radiation field or 2 progressive scans at least 4 weeks
apart or histopathologic confirmation

- Patients must have completed all standard of care treatments including surgical
procedure and radiation therapy (at least 59Gy):

- If the MGMT promoter in their tumor is known to be unmethylated, patients
are not mandated to have received chemotherapy prior to participating in
this trial.

- If the MGMT promoter in their tumor is known to be methylated or the MGMT
promoter status is unknown at the time of screening, patients must have
received at least one chemotherapy regimen prior to participating in this
trial.

6. Location and Extent of Tumor. Because of the potential toxicities from the agent,
patients with neoplastic lesions in the brainstem, cerebellum or spinal cord,
radiological evidence of multifocal disease, or leptomeningeal disease. Patients with
evidence of diffuse subependymal disease or tumor in the brainstem, cerebellum, spinal
cord, or CSF will be excluded. Since the study agent is a local treatment, patients
with radiological evidence of active (growing) multifocal disease, tumors extending
into or crossing the corpus callosum or leptomeningeal disease, will be excluded.

7. Subjects must not have diagnosis of agammaglobulinemia. Patients with the following
will be excluded:

- Undetectable anti-tetanus toxoid IgG (except for retreatment)

- Known history of agammaglobulinemia

8. Patient on greater than 4mg per day of dexamethasone within the 2 weeks prior to
admission for PVSRIPO infusion

9. Patient has worsening steroid myopathy (history of gradual progression of bilateral
proximal muscle weakness, and atrophy of proximal muscle groups)

10. Patients with prior, unrelated malignancy requiring current active treatment with the
exception of cervical carcinoma in situ and adequately treated basal cell or squamous
cell carcinoma of the skin

Eligibility Criteria for Retreatment:

Subjects can be considered for PVSRIPO retreatment if they meet some of the pertinent
inclusion and exclusion criteria above. In addition, the subject must also satisfy the
following criteria:

- Patient must have benefited from initial treatment with PVSRIPO (i.e. be at least 12
months following their initial PVSRIPO infusion).

- Patient must have a recurrence of their supratentorial WHO grade IV malignant glioma
based on imaging studies with measurable disease (≥ 1 cm of contrast-enhancing tumor).

- At the time of biopsy, prior to administration of virus, the presence of recurrent
tumor must be confirmed by histopathological analysis, unless already proven within
the last 3 months via tissue sampling (biopsy or resection).

- The patient must have received a new boost immunization with trivalent inactivated
IPOL™ (Sanofi-Pasteur) at least 1 week and no more than 4 weeks prior to
re-administration of the study agent. The boost immunization may be obtained locally,
prior to signing consent, as long as the patient has been informed about this study
procedure via phone script.

- A new signed informed consent form for retreatment approved by the Duke University
Institutional Review Board (IRB) will be required for retreatment. Patients must be
able to read and understand the informed consent document and must sign the informed
consent indicating that they are aware of the investigational nature of this study.