This prospective, single-arm, exploratory, phase II study was designed to evaluate the efficacy and safety of Trilaciclib in reducing chemotherapy-induced neutropenia in patients with recurrent or metastatic head and neck squamous cell carcinoma. Eligible subjects screened by the inclusion and exclusion criteria will receive chemotherapy alone or combined with immune/targeted therapy and Trilaciclib for 4-6 cycles of continuous treatment. If the efficacy is not progressive after 4-6 cycles of treatment, the investigators can combine with Trilaciclib during immune and/or targeted maintenance therapy according to the specific conditions of the subjects until disease progression or intolerance. The efficacy of Trilaciclib will be evaluated by the incidence of grade ≥3 neutropenia during chemotherapy as the primary endpoint.
After the progression of treatment, if the subjects were treated with chemotherapy for subsequent treatment and were considered to be able to use Trilaciclib according to the evaluation of the investigator, the use of treaclib could be considered until the subjects had disease progression again or were intolerant to treatment.