Randomized Phase 1/2 Evaluation of Neoadjuvant Administration of a Chemokine-Modulatory Regimen in Patients With Recurrent Resectable Colorectal Cancer

A previously-demonstrated correlation between the density of CRC-infiltrating effector T cells and long-term outcomes (Galon et al., 2006; Pages et al., 2005) has been established. In preclinical ex vivo studies performed using explants of resected metastatic CRC, the combination of IFNα with nonselective or COX2-selective inhibitors of prostaglandin synthesis resulted in elevated production of the effector T cell-attracting chemokines CXCL10 and CCL5. This was associated with concomitant suppression of the intratumoral expression of CCL22, a Treg-attracting chemokine (Muthuswamy et al 2008 Canc Res, and Muthuswamy et al, submitted to Canc Res 2011). However, in a subset of patients, the optimal results, particularly with regard to CCL5 induction, required additional stimulation by a third agent, poly-I:C (a toll-like receptor -TLR Ligand).

Therefore, the investigators seek to establish the safety profile of a novel chemokine regimen consisting of IFN, celecoxib and poly-I:C. The investigators also hypothesize that the proposed neoadjuvant chemokine modulation treatment in recurrent CRC patients undergoing tumor resection may increase the density of tumor infiltrating lymphocytes (TILS).

In addition, treatment in the neoadjuvant setting will allow a comparative analysis of the effect of chemokine modulation on the local recruitment of effector-type T cells and the de-recruitment of Treg within resected tumor tissues; helping to determine the "preferred" chemokine-modulating regimen for subsequent extended studies. Such prospective studies will focus on using combinations of chemokine modulation and cancer vaccines in patients with CRC. The investigators have, for example, recently observed that αDC1, a new type of DC vaccine (Kalinski and Okada, 2010; Mailliard et al., 2004) is particularly effective in inducing the effector pathway of T cells differentiation. This was manifested by the induction of tumor-killing function and the induction of effector-type chemokine receptors (CXCR3 and CCR5) (Kalinski and Okada, 2010; Watchmaker et al., 2010). Combining the αDC1 vaccine to a safe, tolerable and efficacious CKM regimen may hold promise for patients with poor prognostic CRC.