Updated results of a phase II trial integrating gefitinib (G) into concurrent chemoradiation (CRT) followed by G adjuvant therapy for locally advanced head and neck cancer (HNC)

Abstract

6028 Background: This study was undertaken to evaluate the tolerability and efficacy of substituting G for paclitaxel into a well- described CRT regimen (Clin Cancer Res 9: 5936; JCO 21: 320) and continuing G as adjuvant therapy. Endpoints included complete response (CR) rate to CRT, progression-free (PFS), disease-specific (DSS) and overall survival (OS), and local & distant control rates. Methods: Previously untreated subjects with stage III, IVa, or IVb squamous cell, poorly differentiated carcinomas, or lymphoepithelioma were enrolled. Organ sparing surgery was allowed. Subjects received 2 cycles of carboplatin/paclitaxel induction followed by CRT with G (250 mg PO qd), 5- fluorouracil, hydroxyurea, and twice daily radiation on day 1–5 of five 14d cycles. G was continued for 2 years from the start of CRT. Results: From 2/03 to 10/04, 67 eligible subjects accrued including 51 males; median age 56; ECOG PS 0 in 47, 1 in 19, and 2 in 1; stage IV in 61 (91%). With median follow-up of 858 days, 9 have had progressive disease (PD, 3 distant, 5 local, 1 with both) and 15 have died (12 related to HNC). Estimated OS=83% at 2y, 73% at 3y; PFS=77% at 2y, 64% at 3y; and DSS=86% at 2y, 80% at 3y. In 56 evaluable subjects we observed 51 CR (91 %), 4 partial responses and 1 PD after CRT. Non-evaluable subjects underwent surgery prior to CRT (10), or died prior to evaluation (1). Grade 3/4 toxicity included mucositis (75%/10%), dermatitis (29%/3%), rash (4%/0%) and diarrhea (1%/0%). Sixty-two patients received maintenance gefitinib, with 60 reliably reporting doses (median days on gefitinib=667). Reasons for holding G included LFT abnormalities, patient refusal, diarrhea, rash, recurrence, hospitalization for acute illness, and early death. Conclusions: Adding G to concurrent CRT after induction therapy, and as adjuvant therapy is tolerable and feasible. Favorable survival and CR data suggest that this is a promising regimen for patients with locally advanced HNC. [Table: see text]