ATTR-01 is the experimental drug being studied in the ATTEST clinical trial. The drug is made from a common cold virus that has been changed to only infect and multiply in cancer cells. This virus delivers an immune therapy drug into the cancer that is intended to promote a participant's own immune system to attack the cancer. The first part of this trial (sub-protocol A) is a phase 1 trial including dose escalation and expansion at one or more doses. It is the first time that ATTR-01 will be given to humans. If an optimal dose is identified, additional sub-protocols will be added by to further elicit whether ATTR-01 may successfully treat cancer. Expanded access is not available.

Inclusion Criteria:

• Consenting male and female adults (18 years of age) with select solid epithelial tumour indications known to have high frequency (75 percent) of αvβ6 integrin receptor expression as detailed in the applicable SP.
• Received and failed/intolerant of Standard of Care (SoC) therapy where eligible (not including neoadjuvant).
• Tumour lesion (not previously irradiated), suitable for safe pre- and post-treatment biopsies.
• Measurable disease by Response Evaluation Criteria in Solid Tumours (RECIST) Version 1.1.
• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of 0 or 1.
• Minimum life expectancy anticipated to be greater than three months
• Willing to undertake appropriate measures of hygiene to prevent any spread of virus and protection of vulnerable individuals.
• Adequate organ function.
• Compliant with requirements for prior treatment washout and contraceptive measures applicable to genetically modified organisms (GMOs) and cancer therapies
• Prior immune checkpoint antibody therapies as single agents or in combination with other anti-cancer agents is permissible.

Exclusion Criteria:

• Significant degree of fibrotic disease, including autoimmune diseases (e.g. systemic lupus, rheumatoid arthritis) or idiopathic and occupation-related pulmonary fibrosis.
• Known prior history of intolerance to anti-programmed cell death protein 1 (PD-1) and/or anti-PD-L1 immunotherapy due to toxicity.
• Has any of the comorbid conditions listed in the detailed protocol exclusion criteria.