Background
Monoclonal antibodies (mAb) have been introduced as a promising new therapeutic approach against SARS-CoV-2. At present, there is little experience regarding their clinical effects in patient populations underrepresented in clinical trials, e.g. immunocompromised patients. Additionally, it is not well known to what extent SARS-CoV-2 treatment with monoclonal antibodies could trigger the selection of immune escape viral variants.
Methods
After identifying immunocompromised patients with viral rebound under treatment with bamlanivimab, we characterized the SARS-CoV-2-isolates by whole genome sequencing. Viral load measurements and sequence analysis were performed consecutively before and after bamlanivimab administration.
Findings
After initial decrease of viral load, viral clearance was not achieved in five of six immunocompromised patients treated with bamlanivimab. Instead, viral replication increased again over the course of the following one to two weeks. In these five patients, the E484K substitution – known to confer immune escape – was detected at the time of viral rebound but not before bamlanivimab treatment.
Interpretation
Treatment of SARS-CoV-2 with bamlanivimab in immunocompromised patients results in the rapid development of immune escape variants in a significant proportion of cases. Given that the E484K mutation can hamper natural immunity, the effectiveness of vaccination as well as antibody-based therapies, these findings may have important implications not only for individual treatment decisions but may also pose a risk to general prevention and treatment strategies.
Funding
All authors are employed and all expenses covered by governmental, federal state, or other publicly funded institutions.
Twelve weeks of SOL/VEL±RBV was safe and highly efficient in HCV GT3 across a diverse patient population. Baseline NS5A RASs were rarely observed and presence did not seem to impact SVR, regardless of the use of RBV.
We analysed SARS-CoV-2 specific antibody responses in 42 social and working contacts of a super-spreader from the Heinsberg area in Germany. Consistent with a high-prevalence setting 26 individuals had SARS-CoV-2 antibodies determined by in-house neutralisation testing. These results were compared with four commercial assays, suggesting limited sensitivity of the assays in such a high-prevalence setting. Although SARS-CoV-2 nucleocapsid restricted tests showed a better sensitivity, spike based assays had a stronger correlation with neutralisation capacity.
Background: Modification of vaccination strategies is needed to improve the immune response to SARS-CoV-2 vaccination in kidney transplant recipients (KTRs).
Methods: This multicenter observational study aimed to determine antibody kinetics among 60 seropositive KTRs and analyzed the effects of the third vaccination against SARS-CoV-2 in 174 previously seronegative KTRs. We investigated whether mycophenolate mofetil (MMF) dose reduction by 25-50% prior the third vaccination influences vaccination success.
Results: 18 of 60 (30%) seropositive KTRs became seronegative in the serological assay within six months. Loss of antibodies was predicted by low initial antibody levels (<≤>206.8 BAU/ml), older age, and impaired graft function. A third vaccination in previously seronegative KTRs induced seroconversion in 56 of 174 (32.1%) KTRs with median antibody levels 119 (76-353) BAU/ml and median neutralizing capacity titer of 1:10 (0-1:40). Multivariate logistic regression revealed that initial antibody levels (OR 1.39, 95% CI 1.09-1.76), graft function (OR 0.05, 95% CI 0.01-0.39), time after transplantation (OR 1.04, 95% CI 1.02-1.07) and MMF trough levels (OR 0.43, 95% CI 0.21-0.88) correlated with seroconversion, p<0.05. After controlling for these confounders, the effect of MMF dose reduction was calculated using propensity score matching. KTRs in the MMF reduction group had significantly lower MMF serum concentrations prior to the third vaccination and were more likely to develop antibody levels <≥>35.2 BAU/ml than their matched KTRs (p=0.02).
Conclusions: Temporary reduction in MMF dose might be a promising approach to improve the immune response in KTRs.
Etravirine (ETR) is a next generation non-nucleoside reverse transcriptase inhibitor (NNRTI). The studies for ETR EMA approval were almost exclusively performed together with the protease inhibitor (PI) darunavir. However the fact that ETR can be active against NNRTI-pretreated HIV variants and that it is well tolerated suggests its application in PI-free antiretroviral combination therapies. Although approved only for PI-containing therapies, a number of ETR treatments without PIs are performed currently. To evaluate the performance of ETR in PI-free regimens, we analyzed the EURESIST database. We observed a total of 70 therapy switches to a PI-free, ETR containing antiretroviral combination with detectable baseline viral load. 50/70 switches were in male patients and 20/70 in females. The median of previous treatments was 10. The following combinations were detected in the EURESIST database: ETR+MVC+RAL (20.0%); ETR+FTC+TDF (18.6%); 3TC+ETR+RAL (7.1%); 3TC+ABC+ETR (5.7%); other combinations (31.4%). A switch was defined as successful when either ≤50 copies/mL or a decline of the viral load of 2 log10, both at week 24 (range 18–30) were achieved. The overall success rate (SR) was 77% (54/70), and for the different combinations: ETR+MVC+RAL=78.6% (11/14); ETR+FTC+TDF=92.3% (12/13); 3TC+ETR+RAL =80.0% (4/5), 3TC+ABC+ETR=100% (SR 4/4); and for other combinations=67.6% (23/34). These SR values are comparable to those for other therapy combinations in such pretreated patients
We present an HIV-1-infected male (who is now 52 years old) with a multi-drug-resistant virus and discuss the considerations finally leading to an antiretroviral regimen resulting in long-term viral suppression and excellent immunological response in a deep salvage situation. Even in a desperate situation with high-level multi-class resistance, highly individual, personalized antiretroviral regimes can be tailor-made to achieve unexpected improvements in the health status of a patient.
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