ASP-1929 Photoimmunotherapy (PIT) Study in Recurrent Head/Neck Cancer for Patients Who Have Failed at Least Two Lines of Therapy

Overall Inclusion Criteria:

• Have a histologically confirmed locoregional persistent, recurrent or second primarysquamous cell carcinoma of the head and neck, not amenable to curative treatment

• Have failed or progressed on or after at least 2 lines of therapy for squamous cellcarcinoma of the head and neck, one of which must be prior systemic platinum-basedchemotherapy

• Have completed prior curative radiation therapy for treatment of their head and neckregion

• Have locoregional head and neck tumor site(s) that are all accessible to lightillumination

• Have target tumors that are clearly measurable by contrast enhanced CT scan, or MRIscan with gadolinium if CT scan is not adequate or the patient has an allergy to CTcontrast media.

• Have a life expectancy of > 6 months, based on Investigator judgment

• Male participants must agree to use contraception during the treatment period andfor at least 6 months after the last ASP-1929 infusion

• Female patients of childbearing potential must not be pregnant or breastfeeding andagree to follow the contraceptive guidance during the treatment period and for atleast 6 months after the last dose of trial intervention and must refrain frombreastfeeding for at least 2 months after the last ASP-1929 infusion

• Have an Eastern Cooperative Oncology Group (ECOG) score of 0 or 1

Overall Exclusion Criteria:

• Have a history of significant (>= Grade 3) cetuximab infusion reactions

• Have been treated with prior systematic chemotherapy or targeted small moleculetherapy or radiation therapy within 2 weeks of trial Day 1 or not recovered fromadverse events due to a previously administered agent

• Have been treated with an anticancer monoclonal antibody therapy within 4 weeks oftrial Day 1 or have not recovered from adverse events due to previously administeredagent

• Have been treated with an investigational agent or intervention within 4 weeks oftrial Day 1 or have not recovered from adverse events, due to previouslyadministered agent or intervention

• Have a present history of distant metastatic disease (M1)

• Have an active undergoing treatment or have a diagnosis of an active cancer otherthan nonmelanoma skin cancer or HNSCC

• Have a tumor in enhanced CT or MRI scan invading a major blood vessel, unless thevessel has been embolized, stented or surgically ligated to prevent potentialbleeding from a blood vessel

• Have impaired hepatic function

• Have impaired renal function

• Have uncontrolled intercurrent illness including, but not limited to, ongoing oractive infection, symptomatic congestive heart failure, unstable angina pectoris,cardiac arrhythmia, or psychiatric illness/social situations that would limitcompliance with trial requirements

• Have been previously treated or randomized to any trial using ASP-1929 or RM-1929PIT as the study treatment