A Phase I/II Open-Label, Non-Randomized Dose Escalation Study of Immunoconjugate L-DOS47

Patients will be recruited into cohorts, with a minimum of three and a maximum of six patients per cohort. All patients at a given dose level must complete Cycle 1 (3 week period) before escalation in subsequent patients can proceed. The decision for dose escalation to the next dose level will be made after the safety and available pharmacokinetic (PK) data have been reviewed by the Trial Steering Committee (TSC). Escalation of L-DOS47 will continue until a maximum tolerated dose (MTD) is reached. After the MTD of L-DOS47 has been determined in Phase I, up to 20 patients will be enrolled (taken forward from Phase I) to evaluate the preliminary efficacy of L-DOS47 (i.e., response rate using the Response Evaluation Criteria in Solid Tumours \[RECIST\] version 1.1 criteria, disease progression and survival); monitoring will include radiologic evaluations every second cycle. The safety and tolerability of L-DOS47 will also be further evaluated. Pharmacokinetic information will be collected as well as relevant observations on the activity of L-DOS47. For all patients, treatment with L-DOS47 will continue either until the patient experiences disease progression, unacceptable toxicity, the patient withdraws consent or has completed four treatment cycles and does not wish to continue with additional cycles, whichever occurs first. After four cycles, patients may continue to receive L-DOS47 for as long as there is sustained clinical benefit and it is well tolerated, in the opinion of the Investigator.