Pancreatic ductal adenocarcinoma in the era of precision medicine

The paradigm for treatment of PDAC is shifting from a "one size fits all" of cytotoxic therapy to a precision medicine approach based on specific predictive biomarkers for a subset of patients. As the genomic landscape of pancreatic carcinogenesis has become increasingly defined, several oncogenic alterations have emerged as actionable targets and their use has been validated in novel approaches such as targeting mutated germline DNA damage response genes (BRCA) and mismatch deficiency (dMMR/MSI-H) or blockade of rare somatic oncogenic fusions. Chemotherapy selection based on transcriptomic subtypes and developing stroma- and immune-modulating strategies have yielded encouraging results and may open therapeutic refinement to a broader PDAC population. Notwithstanding, a series of negative late-stage trials over the last year continue to underscore the inherent challenges in the treatment of PDAC. Multifactorial therapy resistance warrants further exploration in PDAC "omics" and tumor-stroma-immune cells crosstalk. Herein, we discuss precision medicine approaches applied to the treatment of PDAC, its current state and future perspective.

Harnessing the Co-vulnerabilities of Amino Acid-Restricted Cancers

Sustained proliferative potential of cancer cells creates heightened energetic and biosynthetic demands. The resulting overt dependence of cancer cells on unperturbed nutrient supply has prompted a widespread interest in amino acid restriction strategies as potential cancer therapeutics. However, owing to rapid signaling and metabolic reprogramming in cancer cells, the prospects for success of amino acid restriction approaches remain unclear. We thus recognize that the identification of co-vulnerabilities of amino acid-restricted cancers may inform actionable targets for effective combined interventions. In this perspective, we outline the current state of key cellular mechanisms underlying adaptation to amino acid restriction and discuss the role of signal transduction pathways governing cancer cell resistance to amino acid restriction, with potential ramifications for the design of future therapeutic efforts.

The Achilles' Heel of Pancreatic Cancer: Targeting pancreatic cancer's unique immunologic characteristics and metabolic dependencies in clinical trials

Abstract

Pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate and is notoriously refractory to multiple cancer treatments. In recent years, cancer therapy has expanded beyond traditional cytotoxic chemotherapy to targeted agents and immunotherapy which have been successfully implemented in many cancers. Despite robust pre-clinical research, these novel therapies have only had a small impact on PDAC. However, there have been successes with emerging clinical data supporting a potential role for checkpoint inhibitor therapy and targeted therapy with poly (ADP-ribose) polymerase inhibitors for select subsets of PDAC patients. In this clinical review, we discuss recent pre-clinical evidence for targeting metabolic pathways as well as prevalent intratumoral immune subsets, and focus on clinical trials designed to test novel agents in PDAC. The challenge of translating pre-clinical findings to patients remains substantial and many clinical trials yield negative results, but collaborative efforts and renewed focus on novel clinical trials have led to optimism that we will identify additional options for PDAC patients and change outcomes for this deadly disease.

Gemcitabine plus nab-paclitaxel until progression or alternating with FOLFIRI.3, as first-line treatment for patients with metastatic pancreatic adenocarcinoma: The Federation Francophone de Cancérologie Digestive-PRODIGE 37 randomised phase II study (FIRGEMAX)

BACKGROUND

Chemotherapy is effective in metastatic pancreatic adenocarcinoma (mPA), but new approaches are still needed to improve patients' survival and quality of life. We have previously published good efficacy and tolerability results on a sequential treatment strategy of gemcitabine followed by an intensified FOLFIRI (5FU+irinotecan) regimen. In the present study, we evaluated the same sequence but replaced gemcitabine by the new gemcitabine + nab-paclitaxel standard first-line combination.

PATIENTS AND METHODS

We randomised chemotherapy-naive patients with proven mPA, bilirubin levels ≤1.5 upper limit of normal values and performance status 0-2 to alternately receive gemcitabine + nab-paclitaxel for 2 months then FOLFIRI.3 for 2 months in arm A, or gemcitabine + nab-paclitaxel alone until progression in arm B. The primary objective was to increase the 6-month progression-free survival (PFS) rate from 40% (H₀) to 60% (H₁); using the binomial exact method, 124 patients were required. Analyses were carried out in preplanned modified intention-to-treat (mITT) and per-protocol (PP) populations.

RESULTS

Between November 2015 and November 2016, 127 patients were enrolled. Main grade III-IV toxicities (% in arm A/B) were: diarrhoea (12.5/1.7), neutropenia (46.9/31, including febrile neutropenia: 1.6/0), skin toxicity (6.3/13.8), and peripheral neuropathy (6.3/8.6). No toxic deaths occurred. The objective response rate was 40.3% (95% confidence interval [CI]: 28.1-53.6) in arm A and 26.7% (95% CI: 16.1-39.7) in arm B. The primary end-point (6-month PFS rate) was 45.2% [one-sided 95% CI: 34.3-56.4] in arm A and 23.3% in arm B [one-sided 95% CI: 14.3-32.3] in the mITT population. In the PP population, median PFS and OS were 7.6 months and 6 months and 14.5 months and 12.2 months in arm A and B, respectively.

CONCLUSIONS

The FIRGEMAX strategy with gemcitabine + nab-paclitaxel alternating with FOLFIRI.3 every 2 months, appears feasible and effective, with manageable toxicities, in patients able to reach >2mo of treatment.

TRIAL REGISTRATION INFORMATION

EudraCT: 2014-004449-28: NCT: 0282701.

Erythrocytes as Carriers: From Drug Delivery to Biosensors

Drug delivery using natural biological carriers, especially erythrocytes, is a rapidly developing field. Such erythrocytes can act as carriers that prolong the drug's action due to its gradual release from the carrier; as bioreactors with encapsulated enzymes performing the necessary reactions, while remaining inaccessible to the immune system and plasma proteases; or as a tool for targeted drug delivery to target organs, primarily to cells of the reticuloendothelial system, liver and spleen. To date, erythrocytes have been studied as carriers for a wide range of drugs, such as enzymes, antibiotics, anti-inflammatory, antiviral drugs, etc., and for diagnostic purposes (e.g. magnetic resonance imaging). The review focuses only on drugs loaded inside erythrocytes, defines the main lines of research for erythrocytes with bioactive substances, as well as the advantages and limitations of their application. Particular attention is paid to in vivo studies, opening-up the potential for the clinical use of drugs encapsulated into erythrocytes.