Study to Evaluate Safety, Tolerability, and Optimal Dose of Candidate GBM Vaccine VBI-1901 in Recurrent GBM Subjects

This is a two-part, dose-escalation study to define the safety, tolerability, and optimal
dose level of candidate GBM vaccine VBI-1901 with subsequent extension of optimal dose level
in recurrent GBM subjects. Subjects in the dose escalation (Part A of trial) as well as
extension phase of the trial (Part B) will continue to receive vaccine every 4 weeks until
tumor progression per iRANO criteria.

PART A DOSE ESCALATION

Inclusion Criteria: PART A Dose Escalation

1. 18-70 years of age

2. Histologically confirmed WHO grade IV glioblastoma

3. Unequivocal evidence of a tumor recurrence (any number of recurrences) or progression
after an initial treatment regimen (prior to enrollment on this study) as assessed by
MRI of the brain with and without contrast within 30 days prior to the initiation of
injections of VBI‐1901. An initial therapy requires surgery and radiation therapy,
with or without temozolomide. In addition, alternate therapy (with or instead of
temozolomide) is permitted as part of initial therapy.

4. Recovery from the effects of surgery.

5. Corticosteroid (dexamethasone or equivalent) dosage ≤ 4mg daily that has been stable
or decreasing for at least 5 days.

6. Recovery from prior therapy toxicity defined as resolution of all treatment-related
adverse events (AEs) to Grade ≤ 1 or pre-treatment baseline (except alopecia).

7. Karnofsky performance status (KPS) score ≥ 70%.

8. Adequate organ function, including the following:

1. Absolute neutrophil count (ANC) ≥ 1,000/μL, platelets ≥ 100,000/μL

2. Serum creatinine < 1.5 × the upper limit of normal (ULN)

3. Bilirubin < 1.5 × ULN

4. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) < 2.5 × ULN

9. Women of childbearing potential: negative urine pregnancy test within 14 days prior to
the start of VBI-1901 treatment.

10. Female subjects of childbearing potential and sexually active male subjects must agree
to use an acceptable form of contraception for heterosexual activity (i.e., oral
contraceptives, double barrier methods, hormonal injectable, transdermal, or implanted
contraceptives, tubal ligation, or vasectomy of their sexual partner(s) for > 30 days
before Screening, during the study, and for 60 days after the last dose of study
drug).

11. Female subjects without childbearing potential (spontaneous amenorrhea for > 12 months
or surgically sterilized by tubal ligation, hysterectomy, or bilateral oophorectomy >
6 months before Screening) are eligible for inclusion without contraceptive use
restriction.

12. Able and willing to comply with protocol requirements in the opinion of the
Investigator, including being able to have an MRI"

13. Written consent has been obtained.

14. Tumor specimen available for central pathological review.

Exclusion Criteria: PART A Dose Escalation

1. Contrast-enhancing residual tumor that is associated with either diffuse sub-
ependymal or leptomeningeal dissemination.

2. Requirement of systemic corticosteroid therapy > 4 mg/day of dexamethasone or
equivalent or requirement of increasing dose of systemic corticosteroids during the 7
days prior to the start of VBI-1901 treatment.

3. Evidence of HCMV viremia in serum of > 18,200 (4.3Log10) IU/mL using FDA approved
COBAS® AmpliPrep/COBAS® TaqMan® HCMV test (Roche).

4. Surgical resection or major surgical procedure within 4 days prior to the start of
VBI- 1901, or stereotactic biopsy within 7 days prior to the start of VBI-1901.

5. Active infection requiring intravenous antibiotics or antiviral.

6. History of cancer (other than GBM or prostate) within the past 2 years that could
negatively impact survival and/or potentially confound tumor response assessments
within this study.

7. Known immunosuppressive disease or active systemic autoimmune disease such as systemic
lupus erythematosus, human immunodeficiency virus infection, Hepatitis B virus or
Hepatitis C virus infections. Subjects with vitiligo, type 1 diabetes mellitus,
hypothyroidism due to autoimmune condition only requiring hormone replacement therapy,
psoriasis not requiring systemic therapy, or conditions not expected to recur in the
absence of an external trigger are permitted to enroll.

8. Immunosuppressive agent within 4 weeks prior to the start of VBI-1901 treatment.

9. Evidence of intra-tumoral or peri-tumoral hemorrhage on baseline, other than those
that are ≤Grade 1 and either post-operative or stable on at least 2 consecutive MRI
scans.

10. Any condition which in the investigator's opinion makes the subject unsuitable for
study participation.

11. Lack of family or social support structure that would preclude continued participation
in the study.

PART B

Inclusion Criteria: Part B

1. 18-70 years of age.

2. Histologically confirmed WHO grade IV glioblastoma, and no IDH mutation found by
either IHC and/or sequencing during or before screening.

3. Unequivocal evidence of a first tumor recurrence with measurable disease, defined as 1
cm but no greater than 3 cm of enhancing tissue measured in 2 planes (axial, coronal,
or sagittal) after an initial treatment regimen (prior to enrollment on this study)
consisting of surgical intervention (tumor resection) and radiation, with or without
temozolomide chemotherapy, as assessed by MRI of the brain with and without contrast
within 30 days prior to the initiation of injections of VBI‐1901.

4. At least 12 weeks since radiotherapy treatment prior to first dose of VBI‐1901

5. Recovery from the effects of surgery.

6. Corticosteroid (dexamethasone or equivalent) dosage ≤ 4mg daily that has been stable
or decreasing for at least 5 days.

7. Recovery from prior therapy toxicity, defined as resolution of all treatment-related
adverse events (AEs) to Grade ≤ 1 or pre-treatment baseline (except alopecia).

8. Karnofsky performance status (KPS) score ≥ 70%.

9. Adequate organ function, including the following:

1. Absolute neutrophil count (ANC) ≥ 1,000/μL, platelets ≥ 100,000/μL;

2. Serum creatinine < 1.5 × the upper limit of normal (ULN);

3. Bilirubin < 1.5 × ULN;

4. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) < 2.5 × ULN.

10. Women of childbearing potential must have a negative urine pregnancy test within 14
days prior to the start of VBI-1901 treatment.

11. Female subjects of childbearing potential and sexually active male subjects must agree
to use an acceptable form of contraception for heterosexual activity (i.e., oral
contraceptives, double barrier methods, hormonal injectable, transdermal, or implanted
contraceptives, tubal ligation, or vasectomy of their sexual partner(s) for > 30 days
before Screening, during the study, and for 60 days after the last dose of study
drug).

12. Female subjects without childbearing potential (spontaneous amenorrhea for > 12 months
or surgically sterilized by tubal ligation, hysterectomy, or bilateral oophorectomy >
6 months before Screening) are eligible for inclusion without contraceptive use
restriction.

13. Able and willing to comply with protocol requirements, in the opinion of the
Investigator.

14. Written consent has been obtained.

15. Tumor specimen available for central pathological review.

Exclusion Criteria: Part B

1. Contrast-enhancing residual tumor that is any of the following:

1. Greater than 3 cm in 2 planes (axial, coronal, or sagittal);

2. Multi-focal (defined as two separate areas of contrast enhancement measuring at
least 1 cm in 2 planes that are not contiguous on either fluid-attenuated
inversion recovery (FLAIR) or T2 sequences);

3. Associated with either diffuse sub-ependymal or leptomeningeal dissemination.

2. Requirement of systemic corticosteroid therapy > 4 mg/day of dexamethasone or
equivalent or requirement of increasing dose of systemic corticosteroids during the 7
days prior to the start of VBI-1901 treatment.

3. Evidence of HCMV viremia in plasma of >18,200 (4.3log10) IU/mL using FDA approved
COBAS® AmpliPrep/COBAS® TaqMan® HCMV test (Roche).

4. Prior treatment involving immunotherapy, including oncolytic viruses, therapeutic
vaccination, or biologics (e.g. monoclonal antibodies) presumed to have
immunomodulatory effects.

5. Surgical resection or major surgical procedure within 14 days prior to the start of
VBI- 1901, or stereotactic biopsy within 14 days prior to the start of VBI-1901.

6. Radiation therapy, local therapy (except for surgical re-resection), or systemic
therapy following first recurrence/progressive disease. Excluded local therapies
include stereotactic radiation boost, implantation of carmustine biodegradable wafers
(Gliadel), intratumoral or convection- enhanced delivery administered agents, etc.

7. Active infection requiring intravenous antibiotics or antivirals.

8. History of cancer (other than GBM or prostate) within the past 2 years that has
metastatic or local recurrence potential and could negatively impact survival and/or
potentially confound tumor response assessments within this study.

9. Known immunosuppressive disease or active systemic autoimmune disease such as systemic
lupus erythematosus, human immunodeficiency virus infection, Hepatitis B virus or
Hepatitis C virus infections. Subjects with vitiligo, type 1 diabetes mellitus,
hypothyroidism due to autoimmune condition only requiring hormone replacement therapy,
psoriasis not requiring systemic therapy, or conditions not expected to recur in the
absence of an external trigger are permitted to enroll.

10. Immunosuppressive agent within 4 weeks prior to the start of VBI-1901 treatment.

11. Evidence of intra- or peri-tumoral hemorrhage on baseline MRI scan, other than those
that are ≤Grade 1 and either post-operative or stable on at least 2 consecutive MRI
scans.

12. Any condition which in the investigator's opinion makes the subject unsuitable for
study participation.

13. Lack of family or social support structure that would preclude continued participation
in the study.