Trial of pIL-12 Electroporation in Squamous Cell Carcinoma of the Head and Neck (IL12HNSCC)

Inclusion Criteria:

1. Histological or cytological diagnosis of squamous cell carcinoma (SCC) of head and
neck with American Joint Committee on Cancer (AJCC) Stage III, IVA or IVB and not
amenable to surgical resection or locoregional radiation therapy with curative intent.

2. Patients must have measurable disease as defined by Response Evaluation Criteria in
Solid Tumors (RECIST v1.1).

3. Patients must have at least one tumor accessible for intratumoral injection and EP on
investigator's assessment.

4. Patients must have at least one additional lesion (measurable by RECIST v1.1 or
non-target) identified as a control untreated lesion to be left untreated and followed
for response.

5. Patients may have had prior chemotherapy or immunotherapy or radiation therapy. Any
drug-related adverse events (AEs) identified during prior therapy must have been
well-controlled (typically resolution to ≤ Grade 2), or resolved upon investigator
review prior to initiation of the study therapy.

6. Patients must have platinum-refractory disease defined as disease progression within
12 months platinum-based chemoradiation with curative intent or any disease
progression on platinum-based chemotherapy in the absence of radiation.

7. Age ≥ 18 years old.

8. Patients must have agreed to a new biopsy of tumor (deemed accessible and safe for
biopsy by the investigator's assessment) and allowing acquired tissue to be used for
biomarker analysis. If the biopsied lesions were previously irradiated, they must
demonstrate either radiographic or pathological evidence of recurrent or residual
disease.

9. No systemic antineoplastic therapy may have been received between the time of biopsy
and the first administration of study treatment.

10. Eastern Cooperative Oncology Group (ECOG) performance status 0-2.

11. Life expectancy of at least 3 months.

12. Adequate organ function.

13. Female patient of childbearing potential has a negative pregnancy test within 14 days
prior to the start of study drug.

14. Women of child-bearing potential and men must agree to use adequate contraception.

15. Able to give informed consent.

Exclusion Criteria:

1. Prior therapy with IL-12 or prior gene therapy.

2. Concurrent ongoing administration of systemic therapy (e.g. chemotherapy), or
radiation therapy.

3. Evidence of significant active infection (e.g., pneumonia, cellulitis, wound abscess,
etc.) at time of study entry.

4. Pregnant or breast-feeding women are excluded.

5. Patients with electronic pacemakers or defibrillators are excluded.

6. Significant disease or uncontrolled disease, i.e. cardiovascular renal, hepatic,
endocrine, metabolic, neurologic; or other significant disease that would limit the
patients ability to participate in the study as determined by the investigator or
medical monitor.