The role of retinal fluid location in atrophy and fibrosis evolution of patients with neovascular age-related macular degeneration long-term treated in real world

PURPOSE

To assess the effect of clinical factors on the development and progression of atrophy and fibrosis in patients with neovascular age-related macular degeneration (nAMD) receiving long-term treatment in the real world.

METHODS

An ambispective 36-month multicentre study, involving 359 nAMD patients from 17 Spanish hospitals treated according to the Spanish Vitreoretinal Society guidelines, was designed. The influence of demographic and clinical factors, including the presence and location of retinal fluid, on best-corrected visual acuity (BCVA) and progression to atrophy and/or fibrosis were analysed.

RESULTS

After 36 months of follow-up and an average of 13.8 anti-VEGF intravitreal injections, the average BCVA gain was +1.5 letters, and atrophy and/or fibrosis were present in 54.8% of nAMD patients (OR = 8.54, 95% CI = 5.85-12.47, compared to baseline). Atrophy was associated with basal intraretinal fluid (IRF) (OR = 1.87, 95% CI = 1.09-3.20), whereas basal subretinal fluid (SRF) was associated with a lower rate of atrophy (OR = 0.40, 95% CI = 0.23-0.71) and its progression (OR = 0.44, 95% CI = 0.26-0.75), leading to a slow progression rate (OR = 0.34, 95% CI = 0.14-0.83). Fibrosis development and progression were related to IRF at any visit (p < 0.001). In contrast, 36-month SRF was related to a lower rate of fibrosis (OR = 0.49, 95% CI = 0.29-0.81) and its progression (OR = 0.50, 95% CI = 0.31-0.81).

CONCLUSION

Atrophy and/or fibrosis were present in 1 of 2 nAMD patients treated for 3 years. Both, especially fibrosis, lead to vision loss. Subretinal fluid (SRF) was associated with good visual outcomes and lower rates of atrophy and fibrosis, whereas IRF yields worse visual results and a higher risk of atrophy and especially fibrosis in routine clinical practice.

Role of intraretinal and subretinal fluid on clinical and anatomical outcomes in patients with neovascular age-related macular degeneration treated with bimonthly, treat-and-extend and as-needed ranibizumab in the In-Eye study

PURPOSE

To assess the effect of fluid status at baseline (BL) and at the end of the loading phase (LP) of three different ranibizumab regimens: treat-and-extend (T&E), fixed bimonthly (FBM) injections and pro re nata (PRN), in patients with neovascular age-related macular degeneration (nAMD).

DESIGN

Post hoc analysis of the In-Eye study (phase IV clinical trial).

METHODS

Patients were randomized 1:1:1 to the three study arms and were treated accordingly. The presence and type of fluid, intraretinal fluid (IRF) or subretinal fluid (SRF) and the anatomical and visual outcomes were analysed.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA), the mean change from baseline BCVA (BL BCVA), and the proportion of eyes gaining more than 15 letters or losing more than five letters were analysed. Morphological characteristics including the subtype of choroidal neovascular membrane and the development of atrophy and fibrosis were also evaluated.

RESULTS

Patients with SRF at LP had better visual outcomes than patients with IRF. The persistence of SRF did not affect the mean change from BL BCVA among the three treatment regimens. However, in patients with IRF mean change from BL BCVA was significantly lower in the FBM group. The presence of IRF at BL and at the end of the loading phase was associated with the development of fibrosis at the end of the study; this result was contrary to that observed for patients with SRF.

CONCLUSIONS

While SRF is compatible with good visual and anatomical outcomes, IRF leads to worse results in patients with nAMD; our results suggest that patients with IRF have better outcomes when individualized treatment regimens are used (PRN or T&E) in contrast with a FBM regimen.

Omics Approaches in Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma, which represents 80% of pancreatic cancers, is mainly diagnosed when treatment with curative intent is not possible. Consequently, the overall five-year survival rate is extremely dismal—around 5% to 7%. In addition, pancreatic cancer is expected to become the second leading cause of cancer-related death by 2030. Therefore, advances in screening, prevention and treatment are urgently needed. Fortunately, a wide range of approaches could help shed light in this area. Beyond the use of cytological or histological samples focusing in diagnosis, a plethora of new approaches are currently being used for a deeper characterization of pancreatic ductal adenocarcinoma, including genetic, epigenetic, and/or proteo-transcriptomic techniques. Accordingly, the development of new analytical technologies using body fluids (blood, bile, urine, etc.) to analyze tumor derived molecules has become a priority in pancreatic ductal adenocarcinoma due to the hard accessibility to tumor samples. These types of technologies will lead us to improve the outcome of pancreatic ductal adenocarcinoma patients.

Mining Small Routine Clinical Data: A Population Pharmacokinetic Model and Optimal Sampling Times of Capecitabine and its Metabolites

Purpose: The present study was performed to demonstrate that small amounts of routine clinical data allow to generate valuable knowledge. Concretely, the aims of this research were to build a joint population pharmacokinetic model for capecitabine and three of its metabolites (5-DFUR, 5-FU and 5-FUH2) and to determine optimal sampling times for therapeutic drug monitoring. Methods: We used data of 7 treatment cycles of capecitabine in patients with metastatic colorectal cancer. The population pharmacokinetic model was built as a multicompartmental model using NONMEM and was internally validated by visual predictive check. Optimal sampling times were estimated using PFIM 4.0 following D-optimality criterion. Results: The final model was a multicompartmental model which represented the sequential transformations from capecitabine to its metabolites 5-DFUR, 5-FU and 5-FUH2 and was correctly validated. The optimal sampling times were 0.546, 0.892, 1.562, 4.736 and 8 hours after the administration of the drug. For its correct implementation in clinical practice, the values were rounded to 0.5, 1, 1.5, 5 and 8 hours after the administration of the drug. Conclusions: Capecitabine, 5-DFUR, 5-FU and 5-FUH2 can be correctly described by the joint multicompartmental model presented in this work. The aforementioned times are optimal to maximize the information of samples. Useful knowledge can be obtained for clinical practice from small databases.

Hematological Response of Topotecan in Tumor-Bearing Rats: Modeling of the Time Course of Different Cellular Populations

PURPOSE

To evaluate the hematotoxicity of topotecan (TPT) in tumor-bearing rats by a pharmacokinetic/pharmacodynamic approach.

METHODS

DHD/K12-PROb cells were subcutaneously injected in syngenic BD-IX rats. Three weeks after implantation of cells, animals received saline or 6 mg/kg i.p. dose of TPT (group II). Thirty days later, group II was divided into groups IIA receiving a single administration of 6 mg/kg and IIB treated with 3 mg/kg for 2 consecutive days. Leukocytes, neutrophils, and mature lymphocytes were measured in peripheral blood every 48 h for 45 days after first drug administration. Pharmacokinetic characteristics of TPT were also explored.

RESULTS

Disposition of TPT in plasma was best described with a two-compartment model. A semiphysiological model discriminating between system-related and drug-effects parameters, such as the mean cell maturation or transition time (MTT) and the linear concentration-dependent inhibitory effects on cell proliferation (Slp), described adequately the time course of hematotoxicity. The estimates of MTT and Slp for the three cell populations ranged from 1.89 to 2.18 days and from 0.01 to 0.039 ml/ng, respectively.

CONCLUSION

The time course of the hematotoxicity induced after two cycles of chemotherapy with TPT in tumor-bearing rats could be described by a semiphysiological model.

Pharmacokinetic/pharmacodynamic modeling of the antinociceptive effects of (+)-tramadol in the rat: role of cytochrome P450 2D activity

In this study the role of cytochrome P450 2D (CYP2D) in the pharmacokinetic/pharmacodynamic relationship of (+)-tramadol [(+)-T] has been explored in rats. Male Wistar rats were infused with (+)-T in the absence of and during pretreatment with a reversible CYP2D inhibitor quinine (Q), determining plasma concentrations of Q, (+)-T, and (+)-O-demethyltramadol [(+)-M1], and measuring antinociception. Pharmacokinetics of (+)-M1, but not (+)-T, was affected by Q pretreatment: early after the start of (+)-T infusion, levels of (+)-M1 were significantly lower (P < 0.05). However, at later times during Q infusion those levels increased continuously, exceeding the values found in animals that did not receive the inhibitor. These results suggest that CYP2D is involved in the formation and elimination of (+)-M1. In fact, results from another experiment where (+)-M1 was given in the presence and in absence of Q showed that (+)-M1 elimination clearance (CL(ME0)) was significantly lower (P < 0.05) in animals receiving Q. Inhibition of both (+)-M1 formation clearance (CL(M10)) and CL(ME0) were modeled by an inhibitory E(MAX) model, and the estimates (relative standard error) of the maximum degree of inhibition (E(MAX)) and IC(50), plasma concentration of Q eliciting half of E(MAX) for CL(M10) and CL(ME0), were 0.94 (0.04), 97 (0.51) ng/ml, and 48 (0.42) ng/ml, respectively. The modeling of the time course of antinociception showed that the contribution of (+)-T was negligible and (+)-M1 was responsible for the observed effects, which depend linearly on (+)-M1 effect site concentrations. Therefore, the CYP2D activity is a major determinant of the antinociception elicited after (+)-T administration.