Codelivery of TGFß and Cox2 siRNA inhibits HCC by promoting T-cell penetration into the tumor and improves response to Immune Checkpoint Inhibitors.

Upregulation of TGFß and Cox2 in the tumor microenvironment results in blockade of T-cell penetration into the tumor. Without access to tumor antigens, the T-cell response will not benefit from administration of the immune checkpoint antibodies. We created an intravenous polypeptide nanoparticle that can deliver two siRNAs (silencing TGFß and Cox2). Systemic administration in mice, bearing a syngeneic orthotopic hepatocellular carcinoma (HCC), delivers the siRNAs to various cells in the liver, and significantly reduces the tumor. At 2 mg/kg (BIW) the nanoparticle demonstrated a single agent action and induced tumor growth inhibition to undetectable levels after five doses. Reducing the siRNAs to 1mg/kg BIW demonstrated greater inhibition in the presence of PD-L1 mAbs. After only three doses BIW, we could still recover a smaller tumor and, in tumor sections, showed an increase in penetration of CD4+ and CD8+ T-cells deeper into the remaining tumor that was not evident in animals treated with non-silencing siRNA. The combination of TGFß and Cox2 siRNA co-administered in a polypeptide nanoparticle can act as a novel therapeutic alone against HCC and may augment the activity of the immune checkpoint antibodies. Silencing TGFß and Cox2 converts an immune excluded (cold) tumor into a T-cell inflamed (hot) tumor.

Role of miR-155 in the pathogenesis of herpetic stromal keratitis.

Ocular infection with herpes simplex virus 1 can result in a chronic immunoinflammatory stromal keratitis (SK) lesion that is a significant cause of human blindness. A key to controlling SK lesion severity is to identify cellular and molecular events responsible for tissue damage and to manipulate them therapeutically. Potential targets for therapy are miRNAs, but these are minimally explored especially in responses to infection. Here, we demonstrated that Mir155 expression was up-regulated after ocular herpes simplex virus 1 infection, with the increased Mir155 expression occurring mainly in macrophages and CD4(+) T cells and to a lesser extent in neutrophils. In vivo studies indicated that Mir155 knockout mice were more resistant to herpes SK with marked suppression of T helper cells type 1 and 17 responses both in the ocular lesions and the lymphoid organs. The reduced SK lesion severity was reflected by increased phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase 1 and interferon-γ receptor α-chain levels in activated CD4(+) T cells in the lymph nodes. Finally, in vivo silencing of miR-155 by the provision of antagomir-155 nanoparticles to herpes simplex virus 1-infected mice led to diminished SK lesions and corneal vascularization. In conclusion, our results indicate that miR-155 contributes to the pathogenesis of SK and represents a promising target to control SK severity.

Phase III randomized trial comparing the efficacy of cediranib as monotherapy, and in combination with lomustine, versus lomustine alone in patients with recurrent glioblastoma.

PURPOSE: A randomized, phase III, placebo-controlled, partially blinded clinical trial (REGAL [Recent in in Glioblastoma Alone and With Lomustine]) was conducted to determine the efficacy of cediranib, an oral pan-vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor, either as monotherapy or in combination with lomustine versus lomustine in patients with recurrent glioblastoma. PATIENTS AND METHODS: Patients (N = 325) with recurrent glioblastoma who previously received radiation and temozolomide were randomly assigned 2:2:1 to receive (1) cediranib (30 mg) monotherapy; (2) cediranib (20 mg) plus lomustine (110 mg/m(2)); (3) lomustine (110 mg/m(2)) plus a placebo. The primary end point was progression-free survival based on blinded, independent radiographic assessment of postcontrast T1-weighted and noncontrast T2-weighted magnetic resonance imaging (MRI) brain scans. RESULTS: The primary end point of progression-free survival (PFS) was not significantly different for either cediranib alone (hazard ratio [HR] = 1.05; 95% CI, 0.74 to 1.50; two-sided P = .90) or cediranib in combination with lomustine (HR = 0.76; 95% CI, 0.53 to 1.08; two-sided P = .16) versus lomustine based on independent or local review of postcontrast T1-weighted MRI. CONCLUSION: This study did not meet its primary end point of PFS prolongation with cediranib either as monotherapy or in combination with lomustine versus lomustine in patients with recurrent glioblastoma, although cediranib showed evidence of clinical activity on some secondary end points including time to deterioration in neurologic status and corticosteroid-sparing effects.

Cediranib in combination with fulvestrant in hormone-sensitive metastatic breast cancer: a randomized Phase II study.

Hormone receptor-positive breast cancer is treated with estrogen inhibitors. Fulvestrant (FASLODEX™), an estrogen receptor (ER) antagonist with no known agonist effects, competitively binds, blocks and degrades the ER. Vascular endothelial growth factor (VEGF) may mediate resistance to ER antagonists. Cediranib is a highly potent VEGF signaling inhibitor with activity against all three VEGF receptors. This randomized Phase II study evaluated cediranib plus fulvestrant. Postmenopausal women with hormone-sensitive metastatic breast cancer were eligible. The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), duration of response, clinical benefit rate (CBR), safety/tolerability and pharmacokinetics (PK). Patients received cediranib 45 mg/day (n=31) or placebo (n=31) both plus fulvestrant. Demographic/baseline characteristics were well balanced. Patients treated with cediranib had a numerical advantage in PFS (hazard ratio=0.867, P=0.669; median 223 vs. 112 days, respectively) and ORR (22 vs. 8 %, respectively) vs. placebo, although not statistically significant. CBR was 42 % in both arms. The most common adverse events (AEs) in the cediranib arm were diarrhea (68 %), fatigue (61 %) and hypertension (55 %). The incidence of grade ≥ 3 AEs (68 % vs. 32 %), serious AEs (48 % vs. 13 %), discontinuation AEs (39 % vs. 10 %), and cediranib dose reductions/interruptions (74 % vs. 32 %) were higher in the cediranib arm. There was no evidence of a clinically relevant effect of cediranib on fulvestrant PK. Cediranib plus fulvestrant may demonstrate clinical activity in this population, but cediranib 45 mg was not sufficiently well tolerated. Investigation of lower doses of cediranib plus hormonal/chemotherapy could be considered.

Role of miR-132 in angiogenesis after ocular infection with herpes simplex virus.

MicroRNAs (miRNAs) are small regulatory molecules that control diverse biological processes that include angiogenesis. Herpes simplex virus (HSV) causes a chronic immuno-inflammatory response in the eye that may result in corneal neovascularization during blinding immunopathological lesion stromal keratitis (SK). miR-132 is a highly conserved miRNA that is induced in endothelial cells in response to growth factors, such as vascular endothelial growth factor (VEGF). In this study, we show that miR-132 expression was up-regulated (10- to 20-fold) after ocular infection with HSV, an event that involved the production of both VEGF-A and IL-17. Consequently, blockade of VEGF-A activity using soluble VEGF receptor 1 resulted in significantly lower levels of corneal miR-132 after HSV infection. In addition, low levels of corneal miR-132 were detected in IL-17 receptor knockout mice after HSV infection. In vivo silencing of miR-132 by the provision of anti-miR-132 (antagomir-132) nanoparticles to HSV-infected mice led to reduced corneal neovascularization and diminished SK lesions. The anti-angiogenic effect of antagomir-132 was reflected by a reduction in angiogenic Ras activity in corneal CD31-enriched cells (presumably blood vessel endothelial cells) during SK. To our knowledge, this is one of the first reports of miRNA involvement in an infectious ocular disease. Manipulating miRNA expression holds promise as a therapeutic approach to control an ocular lesion that is an important cause of human blindness.

Cediranib in combination with various anticancer regimens: results of a phase I multi-cohort study.

BACKGROUND: Cediranib is a highly potent vascular endothelial growth factor (VEGF) signaling inhibitor of all three VEGF receptors. This phase I, single-center, dose-finding study was designed primarily to investigate the safety and pharmacokinetics (PK) of cediranib with various anticancer regimens in patients with advanced solid tumors. EXPERIMENTAL DESIGN: Oral cediranib 20, 30, and/or 45 mg/day was given in combination with standard mFOLFOX6; docetaxel; irinotecan; irinotecan and cetuximab; or pemetrexed. The novel study design allowed simultaneous evaluation of the safety and PK of these regimens with cediranib in one study. Secondary assessments included a preliminary evaluation of efficacy. RESULTS: Fifty-nine patients received cediranib and were evaluable for safety. The most common adverse events across the study were fatigue and diarrhea (both n = 52). The most common CTC grade ≥ 3 adverse events were neutropenia (n = 19) and fatigue (n = 16). Cediranib did not appear to have a major effect on the PK profile of any chemotherapy agent tested. A preliminary assessment of efficacy showed that objective responses were achieved in some patients (n = 6) who had previously progressed on similar regimens without cediranib. CONCLUSION: In this group of heavily pretreated patients, the study design permitted simultaneous assessment of multiple treatment arms. Treatment with cediranib and the various anticancer regimens was generally well tolerated, with no apparent PK interaction and preliminary evidence of antitumor activity.

Leveraging therapeutic potential of multi-targeted siRNA inhibitors.

While the discovery of RNA interference (RNAi) has been considered one of the most significant breakthroughs in biomedicine, its prospects for novel therapeutic applications are even more exciting. The high specificity, exquisite selectivity and chemical homogeneity of small interfering RNAs (siRNA; intermediates in RNAi activity), provide unique advantages for these moieties as multi-targeted inhibitory drugs. Many such applications have demonstrated significant benefit compared with single gene-targeted siRNA inhibitors. In this article, we will review the current status of using a multi-targeted siRNA cocktail for novel therapeutic development in the treatment of cancer and viral infections. We will also propose the characteristics of various types of siRNA cocktails and their design, while recognizing the potential future impact of and challenges facing this unique therapeutic modality.

Inability of Agrobacterium tumefaciens ribosomes to translate in vivo mRNAs containing non-Shine-Dalgarno translational initiators.

Numerous data accumulated during the last decade have shown that the Shine-Dalgarno (SD) sequence is not a unique initiator of translation for Escherichia coli. Several other sequences, mostly of viral origin, have demonstrated their capability of either enhancing or initiating translation in vivo. A phage T7 gene 10 sequence, called "epsilon" (epsilon), has shown its high enhancing activity on translation in both Escherichia coli and Agrobacterium tumefaciens cells. In this study the epsilon, together with three other nucleotide sequences derived from the 5' non-translated regions of tobacco mosaic virus (TMV), papaya mosaic virus (PMV) and clover yellow mosaic virus (CYMV) RNAs are tested for translation initiation activity in A. tumefaciens cells. The obtained results indicate that none of them was capable of initiating translation in vivo of chloramphenicol acetyltransferase (CAT) mRNA. To determine whether their inactivity was related with structural differences in the ribosomal protein S1, the rpsA gene (coding for S1 protein in E. coli) was co-expressed in A. tumefaciens together with the cat gene placed under the translational control of the above sequences. Our results showed that the rpsA gene product did not make any of the four viral enhancers active in A. tumefaciens cells. The inability of A. tumefaciens ribosomes to translate mRNAs devoid of SD sequences indicates for a substantial difference in the ribosome structure of the two Gram negative bacteria E. coli and A. tumefaciens.