Simeprevir (TMC435) with pegylated interferon/ribavirin in patients coinfected with HCV genotype 1 and HIV-1: a phase 3 study.

BACKGROUND: Simeprevir is an oral, once-daily, hepatitis C virus (HCV) NS3/4A protease inhibitor for the treatment of chronic HCV genotype 1 infection. Human immunodeficiency virus (HIV) coinfection accelerates progression of liver disease. This uncontrolled, open-label trial explored the safety and efficacy of simeprevir in patients with HCV genotype 1/HIV type 1 (HIV-1) coinfection. METHODS: Patients received simeprevir (150 mg once daily) with pegylated interferon alfa-2a/ribavirin (peg-IFN/RBV) for 12 weeks. Noncirrhotic HCV treatment-naive patients and prior relapsers received response-guided therapy (RGT) with peg-IFN/RBV for 24 or 48 weeks. Prior null responders, prior partial responders, and patients with cirrhosis received peg-IFN/RBV for 48 weeks. The primary endpoint was sustained virologic response 12 weeks after the end of treatment (SVR12). RESULTS: One hundred and six patients (93 on antiretroviral therapy) were enrolled and treated. SVR12 rates were 79.2% in HCV treatment-naive patients, 57.1% in prior null responders, 86.7% in prior relapsers, and 70.0% in prior partial responders. Fifty-four of 61 eligible patients (88.5%) met RGT criteria for 24 weeks of peg-IFN/RBV, of whom 87.0% (47/54) achieved SVR12. SVR12 rates were 80.0% (36/45) and 63.6% (14/22) for patients with METAVIR scores of F0-F2 and F3-F4, respectively. Common adverse event (AE) rates were consistent with peg-IFN/RBV therapy (fatigue, headache, nausea, neutropenia). Most AEs were grade 1/2; serious AEs occurred in 5.7% of patients, none of which were fatal. CONCLUSIONS: Simeprevir was generally well tolerated with safety similar to that observed in HCV-monoinfected patients and high SVR12 rates in HCV treatment-naive patients, prior relapsers, prior partial responders, and prior null responders with HIV-1 coinfection. CLINICAL TRIALS REGISTRATION: NCT01479868.

Effects of PEGylation and acetylation of PAMAM dendrimers on DNA binding, cytotoxicity and in vitro transfection efficiency.

Poly(amidoamine) (PAMAM) dendrimers are promising multipotent gene delivery vectors, providing favorable DNA condensation properties also in combination with the possibility of conjugation of different targeting ligands to their surface. They have been used for transfection both in vitro and in vivo, but their application is currently somewhat limited due to inherent cytotoxicity. In this work we investigate how two types of surface modification, acetylation and PEGylation, affect the DNA binding characteristics, the cytotoxicity and the in vitro transfection efficiency of generation 4 and 5 PAMAM dendrimers. Particularly, we address how the morphology of DNA-dendrimer complexes, formed under low salt conditions, changes upon dilution in cell growth medium, an event that inevitably occurs before the complexes reach the cell surface in any transfection experiment. We find that acetylation and PEGylation essentially eliminates the inherent dendrimer cytotoxicity. However, the transfection efficiency of the modified dendrimers is lower than that of the corresponding unmodified dendrimers, which can be rationally understood by our observations that DNA is less condensed when complexed with these modified dendrimers. Although small DNA-dendrimer particles are formed, the availability for ethidium intercalation and nuclease degradation is significantly higher in the modified DNA-dendrimer complexes than in unmodified ones. Dilution in cell growth medium has a drastic effect on these electrostatically assembled complexes, resulting in increase in size and DNA availability. Our results strongly add to the notion that it is of importance to perform a biophysical characterization under conditions as close to the transfection situation as possible, to enable conclusions regarding structure-activity relations of gene delivery vectors.

Modulation of drug-linker design to enhance in vivo potency of homogeneous antibody-drug conjugates.

Antibody-drug conjugates (ADCs) are a promising class of anticancer agents which have undergone substantial development over the past decade and are now achieving clinical success. The development of novel site-specific conjugation technologies enables the systematic study of architectural features within the antibody conjugated drug linker that may affect overall therapeutic indices. Here we describe the results of a systematic study investigating the impact of drug-linker design on the in vivo properties of a series of homogeneous ADCs with a conserved site of conjugation, a monodisperse drug loading, a lysosomal release functionality and monomethyl auristatin E as a cytotoxic payload. The ADCs, which differed only in the relative position of certain drug-linker elements within the reagent, were first evaluated in vitro using anti-proliferation assays and in vivo using mouse pharmacokinetics (PK). Regardless of the position of a discrete polymer unit, the ADCs showed comparable in vitro potencies, but the in vivo PK properties varied widely. The best performing drug-linker design was further used to prepare ADCs with different drug loadings of 4, 6 and 8 drugs per antibody and compared to Adcetris® in a Karpas-299 mouse xenograft model. The most efficacious ADC showed complete tumor regression and 10/10 tumor free survivors at a single 0.5mg/kg dose. This study revealed drug-linker design as a critical parameter in ADC development, with the potential to enhance ADC in vivo potency for producing more efficacious ADCs.