Linaclotide-a novel secretagogue in the treatment of irritable bowel syndrome with constipation and chronic idiopathic constipation.

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are highly prevalent gastrointestinal disorders. Traditional symptoms based therapies had somewhat limited success and efficacy in addressing the disorders. Recently, linaclotide emerged as novel peptide capable of improving abdominal symptoms in patients suffering from IBS-C and CIC. Guanylate cyclase C (GC-C) receptor a multi domain protein, found to be molecular target for linaclotide which acts by activating GC-C receptor on the apical surface of intestinal epithelial cells. Binding of linaclotide to GC-C receptor triggers the elevation of second messenger cGMP that elicits fluid secretion into intestinal cells which play a critical role in maintaining homeostasis through cystic fibrosis transmembrane conductance regulator (CFTR). Data from Phase II and III clinical trials demonstrated that linaclotide seems to produce a statistically significant increase in stool frequency, improved straining, decreased abdominal pain and discomfort.

Enzalutamide: a novel anti-androgen with prolonged survival rate in CRPC patients.

Prostate cancer is the most common malignancy among men found to be the second leading cause of male cancer-related mortality due to development of resistance against androgen deprivation therapy (ADT). With the advancement in understanding of prostate cancer, numbers of agents have been emerged to target Androgen-Receptor (AR) signaling for the treatment of castration resistant prostate cancer (CRPC). Food and Drug Administration (FDA) has recently approved enzalutamide (XTANDI) for the treatment of CRPC. Androgen receptor promotes the prostate cancer progression after transformation. Androgen receptor signaling leads to CRPC when cellular nucleus binds to DNA and increases pro cancer gene expression. In phase ΙΙΙ clinical trial, enzalutamide showed that 160 mg once daily oral administration is well tolerated and significantly enhanced overall survival in men with CRPC after chemotherapy, demonstrated by reduction in the serum prostate specific antigen (PSA) level and increased survival rate by 4.8 months.

Aflibercept: a novel VEGF targeted agent to explore the future perspectives of anti-angiogenic therapy for the treatment of multiple tumors.

Angiogenesis is the process of formation of new blood vessels due to over expression of VEGF (vascular endothelial growth factor) which plays a critical role in the growth and development of all solid tumor types. With the advancement in understanding of tumor angiogenesis and VEGF, there have been a number of agents developed to target VEGF for the treatment of cancer. These targeted agents can affect downstream VEGF signal transduction by unique mechanisms at different cellular and extracellular levels. FDA has recently approved Aflibercept or VEGF-Trap in August 2012 for the treatment of colorectal cancer. It is a recombinant, decoy receptor fusion protein, rationally designed to block angiogenesis by targeting VEGF-A, VEGF-B and placental growth factor. VEGF-Trap exerts its antiangiogenic effects through regression of tumor vasculature, remodelling or normalization of surviving vasculature and inhibition of new tumor vessel growth. In this review, pre-clinical and clinical data have been summarized for aflibercept alone and in combination with chemotherapy to explore its efficacy and benefits in ovarian cancer, breast cancer, non-small cell lung cancer, pancreatic cancer, glioblastoma, adenocarcinoma and renal cell cancer xenograft models.