Histologically or cytologically confirmed MM, a European Cooperative Oncology Group performance status of 0 or 1, prior therapy with alkylators, PI and IMiD, had undergone stem cell transplant (if eligible) and refractory to the last line of treatment (defined as progressive disease on or within 60 days of completion of the last therapy) that included stem cell transplant and those patients with a history of autologous stem cell transplant must have received the transplant >100 days prior to study enrolment and have no active infection.

PK profile (single dose area under the curve, maximum serum concentration [Cmax], time to Cmax , clearance, steady-state volume of distribution [Vss], half-life [t]; repeat dose Cmax and trough plasma concentration), the incidence of anti-drug antibodies, and clinical activity measured as overall response rate (ORR), defined as the percentage of subjects achieving confirmed partial response or better (PR) and clinical benefit rate, defined as the percentages of subjects with minimal response or better (MR).

A phase 3, randomized, double-arm, open-label, controlled trial of ASP-1929 photoimmunotherapy versus physician's choice standard of care for the treatment of locoregional, recurrent head and neck squamous cell carcinoma in patients who have failed or progressed on or after at least two lines of therapy, of which at least one line must be systemic therapy.