Inclusion Criteria:

1. Patients who are willing and able to provide written informed consent to participate
in the study.

2. Patients with histologically confirmed metastatic or recurrent squamous cell
carcinoma of the head or neck currently documented as "progressive disease"

3. Head and neck cancer patients with at least one tumour mass where the tumour mass is
accessible for intratumoural injection and can be measured at periodic intervals for
tumour size using callipers and/or ultrasound.

4. All patients to have histologically confirmed squamous cell carcinoma of the head and
neck (excluding nasopharyngeal) that had recurred or relapsed after surgery and/or
radiotherapy and/or chemotherapy.

5. The longest diameter of the target injectable tumour being no greater than 6 cm or no
less than 1 cm in the longest diameter.

6. The tumour mass to be intratumourally injected to be easily accessible for injection
and amenable to measurement by physical examination and / or radiographically.

7. Patients to be 18 years or older

8. Absence of circulating antibodies to CVA21 (titre < 1:16).

9. Adequate haematological, hepatic and renal function, defined as:

ANC > 1.5 x 109/L, platelets > 100 x 109/L Bilirubin < 20µmol/L, AST < 2.5 times the
upper limit of normal Calculated creatinine clearance > 30 mL/minute

Adequate immunologic function, defined as:

Serum IgG > 5g/L T cell subsets within normal limits

10. Fertile males and females must agree to the use of an adequate form of contraception.
Hormonal contraceptives should be supplemented with an additional barrier method.
Negative pregnancy test is required in female patients of child-bearing potential.

Exclusion Criteria:

1. Patients receiving radiotherapy to the proposed injected tumour or radiotherapy
within the last 3 weeks

2. Performance status > 1 on the ECOG scale

3. Life expectancy < 3 months.

4. Pregnancy or breastfeeding.

5. Primary or secondary immunodeficiency, including immunosuppressive disease, and
immunosuppressive doses of corticosteroids (e.g. prednisolone > 7.5mg per day) or
other immunosuppressive medications including cyclosporine, azathioprine,
interferons, within the past 4 weeks.

6. Positive serology for HIV, Hepatitis B or Hepatitis C.

7. Splenectomy.

8. Presence of uncontrolled infection.

9. Any uncontrolled medical condition that in the opinion of the Investigator is likely
to place the patient at unacceptable risk during the study or reduce their ability to
complete the study

10. Participation in another study requiring administration of an investigational drug or
biological agent within the last 4 weeks

11. Known allergy to treatment medication or its excipients

12. Tumours to be injected lying in mucosal regions or close to an airway, major blood
vessel or spinal cord that, in the opinion of the Investigators, could cause
occlusion or compression in the case of tumour swelling or erosion into a major
vessel in the case of necrosis