Conatumumab

Although various therapies are available for the treatment of metastatic colorectal cancer (mCRC), there is lack of head-to-head evidence. Recent studies have demonstrated the efficacy of chemotherapy in combination with different biological agents including regorafenib in second-line therapy in patients with mCRC. We conducted a network meta-analysis (NMA) to estimate the relative efficacy and safety of regorafenib in combination with chemotherapy compared to other biological agents with chemotherapy combinations.

A literature search was conducted in PubMed, Embase, and Cochrane databases to identify all randomized controlled trials (RCTs) evaluating the efficacy and safety of bevacizumab, regorafenib, panitumumab, cetuximab, ramucirumab, conatumumab, ganitumab, and aflibercept in combination with chemotherapy against chemotherapy alone as second-line setting from inception to 7 February 2019 in patients with mCRC. The survival outcomes were analyzed by the frequentist statistical approach (R software, netmeta package) while the level of individual treatment arms was assessed using the Bayesian method (R software, gemtc package).

We identified 12 articles involving eight RCTs studies analyzing 6805 patients. The studies compared bevacizumab (3), regorafenib (1), panitumumab (2), cetuximab (3), ramucirumab (1), conatumumab (1), ganitumab (1), and aflibercept (1) against chemotherapy alone as comparator. The progression-free survival (PFS) revealed that regorafenib performed better than aflibercept (HR 0.9631, 95% CI 0.6785-1.367), ganitumab (HR 0.7228, 95% CI 0.3985-1.3109), panitumumab (HR 0.9653, 95% CI 0.6781-1.3742), and ramucirumab (HR 0.9206, 95% CI 0.6504-1.303). Regorafenib performed better than bevacizumab (OR 0.797, 95% CI 0.328-1.88) in terms of tumor response. Safety analysis showed that regorafenib performed better in reducing grade ≥ 3 adverse events (AE) than cetuximab and conatumumab, neutropenia than conatumumab, and fatigue than cetuximab.

Regorafenib combined with chemotherapy might be a potential alternative to conventional therapeutic options in second-line treatment of patients with metastatic colorectal cancer and could be considered as the best option for treating patients with KRAS and BRAF mutated mCRC. However future RCTs are needed to confirm these results.

Pancreatic cancer is usually advanced and drug resistant at diagnosis. A potential therapeutic approach outlined here uses nanoparticle (NP)-based drug carriers, which have unique properties that enhance intra-tumor drug exposure and reduce systemic toxicity of encapsulated drugs. Here we report that patients whose pancreatic cancers express elevated levels of Death Receptor 5 (DR5) and its downstream regulators/effectors FLIP, Caspase-8, and FADD had particularly poor prognoses. To take advantage of elevated expression of this pathway, we designed drug-loaded NPs with a surface-conjugated αDR5 antibody (AMG 655). Binding and clustering of the DR5 is a prerequisite for efficient apoptosis initiation, and the αDR5-NPs were indeed found to activate apoptosis in multiple pancreatic cancer models, whereas the free antibody did not. The extent of apoptosis induced by αDR5-NPs was enhanced by down-regulating FLIP, a key modulator of death receptor-mediated activation of caspase-8. Moreover, the DNA topoisomerase-1 inhibitor camptothecin (CPT) down-regulated FLIP in pancreatic cancer models and enhanced apoptosis induced by αDR5-NPs. CPT-loaded αDR5-NPs significantly increased apoptosis and decreased cell viability in vitro in a caspase-8- and FADD-dependent manner consistent with their expected mechanism-of-action. Importantly, CPT-loaded αDR5-NPs markedly reduced tumor growth rates in vivo in established pancreatic tumor models, inducing regressions in one model. These proof-of-concept studies indicate that αDR5-NPs loaded with agents that downregulate or inhibit FLIP are promising candidate agents for the treatment of pancreatic cancer.