VITAL phase 2 study: Upfront 5-fluorouracil, mitomycin-C, panitumumab and radiotherapy treatment in nonmetastatic squamous cell carcinomas of the anal canal (GEMCAD 09-02).

AIM: VITAL, a phase II single-arm study, aimed to evaluate efficacy and safety of panitumumab addition to 5-fluorouracil (5-FU), mitomycin-C (MMC) and radiotherapy (RT) in patients with localized squamous cell carcinoma of the anal canal (SCCAC). METHODS: Adult, treatment-naïve SCCAC patients (Stage T2-T4, any N, M0) and ECOG-PS ≤2, received panitumumab (6 mg/kg, day 1 and Q2W; 8 weeks), 5-FU (1000 mg/m2 /d, days 1-4 and 29-32), MMC (10 mg/m2 , days 1 and 29) and RT 45 Gy (1.8 Gy/fraction) to the primary tumor and mesorectal, iliac and inguinal lymph nodes, plus 10-15 Gy boost dose to the primary tumor and affected lymph nodes. The primary objective was disease free survival rate (DFS) at 3-years (expected 3-year DFS rate: 73.7 ± 12%). RESULTS: Fifty-eight patients (31 women; median age: 59 years; ECOG-PS 0-1:98%; TNM II [29%] (T2 or T3/N0/M0)/IIIA (T1-T3/N1/M0 or T4/N0/M0) [21%]/IIIB (T4/N1/M0 or any T/N2 or N3/M0) [47%]/nonevaluable [4%]) were included. The median follow-up was 45 months. The 3-year DFS rate was 61.1% (95% CI: 47.1, 72.4). The 3-year overall survival rate was 78.4% (95% CI: 65.1, 87.1). Eighteen patients (31.0%) required a colostomy within 2 years posttreatment. Grade 3-4 toxicities were experienced by 53 (91%) patients. Most common grade 3-4 treatment-related events were radiation skin injury (40%) and neutropenia (24%). No toxic deaths occurred. Improved efficacy in colostomy-free survival and complete response rate was observed in human papilloma virus positive patients. CONCLUSIONS: Panitumumab addition to MMC-5FU regimen in SCCAC patients increases toxicity and does not improve patients' outcomes. RT plus MMC-5FU remains the standard of care for localized SCCAC patients.

Nuclear IGF-1R predicts chemotherapy and targeted therapy resistance in metastatic colorectal cancer.

BACKGROUND: Although chemotherapy is the cornerstone treatment for patients with metastatic colorectal cancer (mCRC), acquired chemoresistance is common and constitutes the main reason for treatment failure. Monoclonal antibodies against insulin-like growth factor-1 receptor (IGF-1R) have been tested in pre-treated mCRC patients, but results have been largely deceiving. METHODS: We analysed time to progression, overall survival, and the mutational status of RAS, BRAF and nuclear p-IGF-1R expression by immunohistochemistry, in 470 metastatic CRC patients. The effect of IGF-1R activation and distribution was also assessed using cellular models of CRC and RNAi for functional validation. RESULTS: Nuclear IGF-1R increased in metastatic tumours compared to paired untreated primary tumours, and significantly correlated with poor overall survival in mCRC patients. In vitro, chemo-resistant cell lines presented significantly higher levels of IGF-1R expression within the nuclear compartment, and PIAS3, a protein implicated also in the sumoylation process of intranuclear proteins, contributed to IGF-1R nuclear sequestration, highlighting the essential role of PIAS3 in this process. Intriguingly, we observed that ganitumab, an IGF-1R blocking-antibody used in several clinical trials, and dasatinib, an SRC inhibitor, increased the nuclear localisation of IGF-1R. CONCLUSIONS: Our study demonstrates that IGF-1R nuclear location might lead to chemotherapy and targeted agent resistance.