The use of multiple drugs in a single clinical trial or as a therapeutic strategy has become common, particularly in the treatment of cancer. Because traditional trials are designed to evaluate one agent at a time, the evaluation of therapies in combination requires specialized trial designs. In place of the traditional separate phase I and II trials, this trial uses a single phase I/II clinical trial to evaluate simultaneously the safety and efficacy of combination dose levels, and select the optimal combination dose.

Therefore, this is a two part trial of Debio 1143 combined with concurrent cisplatin and radiotherapy (CRT) in participants with previously untreated stage III, IVa or IVb head and neck cancer. The trial begins with an initial period of dose escalation (Phase I) to investigate the maximum tolerated dose (MTD) of Debio 1143 that can safely be given in combination with CRT.

Using the MTD determined in the Phase I portion, the randomized phase II trial in 94 participants compares Debio 1143 to placebo, both with concomitant CRT. The aim is to evaluate the efficacy and safety of Debio 1143.

Inclusion Criteria:

• Meets protocol-specified criteria for qualification and contraception
• Is willing and able to comply with study procedures and restrictions related to food, drink and medications
• Voluntarily consents to participate and provides written informed consent prior to any protocol-specific procedures

Exclusion Criteria:

• Has history or current use of over-the-counter medications, dietary supplements, or drugs (including nicotine and alcohol) outside protocol-specified parameters

• Has signs, symptoms or history of any condition that, per protocol or in the opinion of the investigator, might compromise:

  1. the safety or well-being of the participant or study staff;
  2. the safety or well-being of the participant's offspring (such as through pregnancy or breast-feeding);
  3. the analysis of results