Clinical and immunological evaluation of schizophyllan (SPG) in combination with standard chemotherapy in patients with head and neck squamous cell carcinoma

A phase II randomized controlled trial was carried out to evaluate the clinical efficacy and tolerability of Schizophyllan (SPG) used in combination with standard chemotherapy in the neoadjuvant setting in patients with locally advanced head and neck squamous cell carcinoma. Several immunological parameters were considered to assess the immunoregulatory activity of SPG in the same patients. The clinical and immunological evaluations were performed both before and at the end of the study (4 months later). All patients received standard chemotherapy for head and neck squamous cell carcinoma according to one of the following treatment regimens: 1) cisplatin 100 mg/m2 i.v. day 1, 5-FU 1,000 mg/m2 i.v. continuous infusion days 1 to 5; 2) cisplatin 80 mg/m2 i.v. day 1, 5-FU 600 mg/m2 i.v. over 4 h days 2 to 5, vinorelbine 20 mg/m2 i.v. days 2 and 8. Antineoplastic regimens were repeated every 28 days x 4 cycles for approximately 4 months. SPG was administered weekly at a single dose of 40 mg intramuscularly for 4 months in addition to standard chemotherapy. Twenty-six patients were enrolled in the study, 22 of whom were evaluable. Thirteen patients were assigned to Arm A (treatment with SPG associated with chemotherapy, regimen 1 or 2) and 9 patients to Arm B (treatment with chemotherapy, regimen 1 or 2, alone). The overall response rate was not significantly different between the two Arms (92.3% in Arm A vs. 100% in Arm B), although a higher number of complete responses (CR) (3 = 23.1%) was registered in Arm A. Overall, the SPG treatment does not seem to have induced significant changes of the immunological parameters of our patients: this may be due to both the advanced cancer stage and the effect of chemotherapy, which are both well known causes of immunodepression. The significant differences between the two Arms were only: the CD8+ lymphocytes were decreased in the patients treated with SPG and increased in controls; serum levels of IL-1α was lower in patients treated with SPG than in the control group; the production in culture of IL-1α was higher in Arm A than in Arm B and IL-6 was higher in Arm B than in Arm A. Treatment with SPG was proven safe and was well-tolerated by all patients.