AB58. Phase II study of safety and clinical outcome for Nimotuzumab and concurrent capecitabine and radiotherapy for patients with locally advanced inoperable or relapsed/ residual gastric cancer

Objective: To evaluate the toxicities and clinical outcome of phase II prospective study of Nimotuzumab and concurrent capecitabine and radiotherapy for patients with locally advanced inoperable or relapsed/ residual gastric cancer.

Materials & methods: From March, 2010 to December, 2012, 24 pathologically proved gastric cancer patients with life expectancy of more than 3 months and measurable lesions were enrolled in a phase II study. The inclusion criteria included locally advanced inoperable gastric cancer, postoperative relapsed/residual gastric cancer, and distant metastasis which could be controlled by radiotherapy. All patients received intensity-modulated radiotherapy (IMRT) (54 Gy in 30 fractions for gross tumor and/or 45 Gy in 25 fractions for prophylactic area) and concurrent capecitabine (1,600 mg/m²/d for 35 days) and Nimotuzumab (200 mg once a week). Acute toxicity was scored according to the Common Terminology Criteria for Adverse Events (CTCAE version 3.0), and local and systematic efficacy was evaluated on the basis of RECIST [2000] criteria.

Results: The ratio of men to women was 3.8:1. The median age was 57 years old, with a range from 35 to 65 years. There were 20 and 4 patients with postoperative relapsed/residualtumor and locally advanced inoperable gastric cancer, respectively. All patients except 2 (1 with poor renal function and the other refused chemotherapy) received prior chemotherapy with a median of 7 cycles (2 to 19) and suffered disease progression after chemotherapy. During concurrent chemoradiotherapy, 3 patients (12.5%) had Grade III acute toxicities, mainly thrombocytopenia (12.5%). No allergy or skin rash was observed. There were 3, 6 and 3 patients had radiotherapy, capecitabine and Nimotuzumab interruption due to acute side effects, respectively. Twenty patients could be evaluated 1 month after the end of radiotherapy. The in-field response and SD rate, and systematic response and SD rate was 50% (CR of 5%, PR of 45%), 50%, and 35%, 40%, respectively. With the median follow-up of 9.1 months, the 1-year overall survival (OS), in-field progression free survival (IFPFS) and progression free survival (PFS) was 58.3%, 89.2% and 31.1%, respectively. Thirteen patients had disease progression with majority out of field (12/13), only 1 both within the field and out of field. The median failure time was 5.3 (1.5 to 9.2) months.

Conclusions: Concurrent capecitabine and Nimotuzumab chemoradiotherapy is safe and tolerable for locally advanced inoperable or relapsed/residual gastric cancer. This treatment modality achieved good in-field control. Distant metastasis occurred early and is the main treatment failure even though most patients received prior chemotherapy.

Keywords: Gastric cancer; capecitabine; Nimotuzumab; concurrent chemoradiotherapy; phase II clinical study