Addressing bedaquiline treatment interruptions in the treatment of drug-resistant TB.

SETTING: The recommended dosing regimen for bedaquiline (BDQ), consisting of a 2-week loading phase (400 mg/day), followed by a maintenance phase (200 mg three times/week), might pose challenges when treatment is interrupted and needs to be reinitiated. Guidance on BDQ treatment re-initiation is, therefore, needed.OBJECTIVE: This pharmacokinetic-based simulation study aimed to provide recommendations for re-initiating BDQ following treatment interruptions.DESIGN: Simulations of treatment interruptions, defined as any time a patient misses ≥2 consecutive BDQ doses for up to 56 consecutive days (2 months), were assessed using the BDQ population-pharmacokinetic model.RESULTS: Any treatment interruption lasting ≤28 days prior to completing the 14-day loading phase can be managed by completing the remaining loading doses. Scenarios when it is sufficient to simply restart maintenance dosing are discussed. In some scenarios, treatment interruptions require reloading for 1 week prior to restarting maintenance dosing.CONCLUSIONS: This simulation study provided recommendations for managing BDQ treatment interruptions and underscores the importance of having a robust population-pharmacokinetic model for TB drugs to inform clinical guidance. Such recommendations are valuable to help ensure optimal treatment with BDQ for treating multidrug-resistant TB.

Bedaquiline for multidrug-resistant TB in paediatric patients.

BACKGROUND: TMC207-C211 (NCT02354014) is a Phase 2, open-label, multicentre, single-arm study to evaluate pharmacokinetics, safety/tolerability, antimycobacterial activity and dose selection of bedaquiline (BDQ) in children (birth to <18 years) with multidrug-resistant-TB (MDR-TB).METHODS: Patients received 24 weeks' BDQ with an anti-MDR-TB background regimen (BR), followed by 96 weeks of safety follow-up. Results of the primary analysis are presented based on data up to 24 weeks for Cohort 1 (≥12-<18 years; approved adult tablet at the adult dosage) and Cohort 2 (≥5-<12 years; age-appropriate 20 mg tablet at half the adult dosage).RESULTS: Both cohorts had 15 patients, of whom respectively 53% and 40% of Cohort 1 and Cohort 2 children had confirmed/probable pulmonary MDR-TB. Most patients completed 24 weeks´ BDQ/BR treatment (Cohort 1: 93%; Cohort 2: 67%). Geometric mean BDQ area under the curve 168h values of 119,000 ng.h/mL (Cohort 1) and 118,000 ng.h/mL (Cohort 2) at Week 12 were within 60-140% (86,200-201,000 ng.h/mL) of adult target values. Few adverse event (AE) related discontinuations or serious AEs, and no QTcF >460 ms during BDQ/BR treatment or deaths occurred. Of MGIT-evaluable patients, 6/8 (75%) Cohort 1 and 3/3 (100%) Cohort 2 culture converted.CONCLUSION: In children and adolescents aged ≥5-<18 years with MDR-TB, including pre-extensively drug-resistant-TB (pre-XDR-TB) or XDR-TB, 24 weeks of BDQ provided a comparable pharmacokinetic and safety profile to adults.

Exploitation of Langerhans cells for in vivo DNA vaccine delivery into the lymph nodes.

There is no clinically available cancer immunotherapy that exploits Langerhans cells (LCs), the epidermal precursors of dendritic cells (DCs) that are the natural agent of antigen delivery. We developed a DNA formulation with a polymer and obtained synthetic 'pathogen-like' nanoparticles that preferentially targeted LCs in epidermal cultures. These nanoparticles applied topically under a patch-elicited robust immune responses in human subjects. To demonstrate the mechanism of action of this novel vaccination strategy in live animals, we assembled a high-resolution two-photon laser scanning-microscope. Nanoparticles applied on the native skin poorly penetrated and poorly induced LC motility. The combination of nanoparticle administration and skin treatment was essential both for efficient loading the vaccine into the epidermis and for potent activation of the LCs to migrate into the lymph nodes. LCs in the epidermis picked up nanoparticles and accumulated them in the nuclear region demonstrating an effective nuclear DNA delivery in vivo. Tissue distribution studies revealed that the majority of the DNA was targeted to the lymph nodes. Preclinical toxicity of the LC-targeting DNA vaccine was limited to mild and transient local erythema caused by the skin treatment. This novel, clinically proven LC-targeting DNA vaccine platform technology broadens the options on DC-targeting vaccines to generate therapeutic immunity against cancer.

Lowering the dose of hydroxyurea minimizes toxicity and maximizes anti-HIV potency.

The goal of this study was to optimize the hydroxyurea dosage in HIV-infected patients, and to minimize the toxicity and maximize the antiviral efficacy of the hydroxyurea-didanosine combination. In a randomized, open-label study (RIGHT 702, a multicenter trial performed in private and institutional practices), three daily doses (600 microg, 800-900 microg, and 1200 microg) of hydroxyurea were administered in combination with didanosine and stavudine to 115 chronically HIV-infected patients, one-third antiretroviral drug naive, with viremia between 5000 and 200,000 copies/ml regardless of CD4+ cell count. The primary efficacy end point was the proportion of patients with plasma HIV-1 RNA levels below 400 copies/ml after 24 weeks of therapy. In the RIGHT 702 intent-to-treat population the lowest (600 mg) dose of hydroxyurea was better tolerated, associated with fewer adverse events, and more potent by all efficacy parameters, including the primary end point (76 versus 60% patients with viremia<400 copies/ml at week 24 for the 600-mg and 800- to 900-mg dose groups, respectively; p=0.027), the mean area under the curve (60.3 versus 65.8; p=0.016), and the mean log10 decrease (-1.95 versus -0.77; p=0.001). Patients receiving 600 mg of hydroxyurea daily also had the highest CD4+ cell count, CD4+/CD8+ cell ratio, and lowest CD8+ cell count and percentage (p=0.035). The RIGHT 702 trial provides an explanation for the increased toxicity and decreased efficacy of hydroxyurea when it was used at high dosage (1200 mg daily). At the optimal dosage of 600 mg daily, hydroxyurea, in combination with didanosine, deserves reevaluation for the long-term management of HIV/AIDS worldwide, because of its excellent resistance profile, durability, and affordability.

Prevalence of Aspergillus fumigatus and other fungal species in the sputum of adult patients with cystic fibrosis.

Aspergillus fumigatus is often found in the respiratory tract secretions of patients with cystic fibrosis (CF), although the role of the fungus for progression of pulmonary disease remains unclear. This study aimed to investigate the frequency of A. fumigatus and other fungi in sputum of adult CF patients using different methods for culture and microscopy. Results from the analysis of 369 samples from 94 patients showed that A. fumigatus could be isolated in 45.7% of patients. Other moulds were rare, but the yeast Candida albicans was another frequent isolate, detected in 75.5% of patients. A comparison of different culture media showed no difference between a selective medium developed to specifically inhibit Pseudomonas aeruginosa and a standard fungal culture medium for growth of A. fumigatus, although both were more efficient for detection of fungi than other bacterial culture media. Fluorescent microscopy with calcofluor white was more sensitive for detection of fungal hyphae in undiluted sputum than standard methylene blue staining. This study shows that A. fumigatus and C. albicans have a high frequency in adult CF patients. Microbiological analysis should routinely include methods for specific identification of fungi to monitor for potential complications arising from fungal disease in these patients.

Modified short-course chemotherapy of pulmonary tuberculosis in Ibadan, Nigeria--a preliminary report.

Over a 3 year period 3rd of April 1995 and 6th of April 1998 a controlled clinical trial of the modified short-course chemotherapy (SSC) in newly diagnosed cases of pulmonary tuberculosis in Nigeria was carried out. Between The SCC used was the one adopted from World Health Organisation/International Union Against Tuberculosis and Lung Diseases for developing countries by the Nigerian National Tuberculosis and Leprosy Control Programme (NTLCP). The regimen used consisted of streptomycin (S), isoniazid (H), Rifampicin (R) and pyrazinamide (Z) in the initial or intensive phase of 2 months. Ethambutol (E) was sometimes substituted for streptomycin. The continuation phase was 6 months of thiacetazone, (T) and isoniazid (H), i.e., 2SHRZ/6TH or 2EHRZ/6TH. Sputum conversion was 90% at the second month of treatment and there was no bacteriological relapse after 18 months of follow-up. Side effects were few and consisted mainly of acne vulgaris which occurred in twenty (20.6%) of 97 patients during the continuation phase. It is concluded that the 8-month chemotherapy regimen adopted by NTLCP is efficacious in treatment of smearpositive pulmonary tuberculosis (PTB).