Novel approaches to HIV therapy

A landscape of response to drug combinations in non-small cell lung cancer

Combination of anti-cancer drugs is broadly seen as way to overcome the often-limited efficacy of single agents. The design and testing of combinations are however very challenging. Here we present a uniquely large dataset screening over 5000 targeted agent combinations across 81 non-small cell lung cancer cell lines. Our analysis reveals a profound heterogeneity of response across the tumor models. Notably, combinations very rarely result in a strong gain in efficacy over the range of response observable with single agents. Importantly, gain of activity over single agents is more often seen when co-targeting functionally proximal genes, offering a strategy for designing more efficient combinations. Because combinatorial effect is strongly context specific, tumor specificity should be achievable. The resource provided, together with an additional validation screen sheds light on major challenges and opportunities in building efficacious combinations against cancer and provides an opportunity for training computational models for synergy prediction.

Tenofovir alafenamide vs. tenofovir disoproxil fumarate: an updated meta-analysis of 14 894 patients across 14 trials

BACKGROUND

Both tenofovir disoproxil fumarate (TDF)/emtricitabine and tenofovir alafenamide (TAF)/emtricitabine demonstrate excellent efficacy and safety overall, but concerns remain over specific changes in markers of bone and renal function. Lower plasma tenofovir concentrations are seen with TAF and in unboosted regimens. We assess TAF vs. TDF safety with and without booster coformulation.

METHODS

A previous systematic review was updated with recent clinical trials. TAF vs. TDF efficacy and safety were compared in boosted and unboosted subgroups. Efficacy was measured by viral suppression. Key safety endpoints included all adverse events, serious adverse events, Grades 3-4 adverse events and adverse event discontinuation. Further specific renal and bone markers were also assessed.

RESULTS

A total of 14 clinical trials comparing TDF and TAF regimens were identified. A significant difference (P = 0.0004) in efficacy was shown in the boosted subgroup in favour of TAF, but no difference was seen in the unboosted subgroup. There were no significant differences between TAF and TDF for any of the key safety endpoints analysed. No differences were seen for the bone markers analysed. No difference was found for renal tubular events. There was a difference in risk for discontinuation due to renal adverse events when boosted (P = 0.03), but none when unboosted.

CONCLUSION

Across all main safety endpoints, no differences between TAF and TDF are seen. Boosted TDF regimens were associated with lesser comparative efficacy than boosted TAF and a higher risk of renal event discontinuation. However, modern antiretroviral regimens are more commonly unboosted. This study finds no difference in efficacy or safety in unboosted TAF vs. TDF.

96-week results of a dual therapy with darunavir/ritonavir plus rilpivirine once a day vs triple therapy in patients with suppressed viraemia: virological success and non-HIV related morbidity evaluation

Antiretroviral therapies have been tested with the goal of maintaining virological suppression with a particular attention in limiting drug-related toxicity. With this aim we designed the DUAL study: a randomized, open-label, multicenter, 96 weeks-long pilot exploratory study in virologically suppressed HIV-1+ patients with the aim of evaluating the immunovirological success and the impact on non-HIV related morbidity of switching to a dual therapy with darunavir-ritonavir (DRV/r) and rilpivirine (RPV). We recruited patients who received a PI/r-containing HAART for ≥6 months, HIV-RNA < 50 cp/mL for ≥3 months, eGFR > 60 mL/min/1,73m2, without DRV or RPV RAMs. We randomized patients in arm A: RPV + DRV/r QD or arm B: ongoing triple therapy. The primary endpoint has been defined as the percentage of patients with HIV-RNA < 50 cp/mL at week 48 (ITT). VACS index, Framingham CVD risk (FRS) and urinary RBP (uRBP) were calculated. We used Chi-square or Fisher statistics for categorical variables and Mann-Whitney U for continuous ones. Forty-one patients were enrolled (22 in arm A, 14 in arm B, plus 5 screening failures): 30 patients reached 96 weeks: 100% had HIV-RNA < 50 cp/mL in arm A versus 91.7% in arm B. Similar changes were observed in median CD4/mL between baseline and week 96 (+59 versus - 31, p: n.s.). Thirty-one in arm A and 23 in arm B adverse events took place, whereas only 1 was serious (arm A: turbinate hypertrophy, unrelated to HAART). Among the 6 discontinuations (3 in A, 3 in B), only 1 was related to adverse event (arm A: G3 depression, insomnia, weakness). VACS index, median FRS and median uRBP values did not vary from baseline to week 96. At 96-weeks all patients switched to a QD 2-drug regimen based on DRV/r + RPV maintained HIV-RNA suppression, but a single patient who showed a virological failure at week 4. CD4 counts increased overtime without significant differences between the two arms. The novel dual regimen was well tolerated with the same amount of discontinuation as the control arm. VACS index, FRS and uRBP did not differ between arms at week 96.

Role of medicinal plants in HIV/AIDS therapy

Human immunodeficiency virus (HIV) causes the potentially life-threatening and chronic disease called acquired immune deficiency syndrome (AIDS). The main target of this viral disease is to suppress the immune system and make the body unresponsive to external stimuli. According to global health observatory data since epidemic, more than 78 million people were affected by HIV and 39 million people died globally. Until 2017, 36.5 million people were living with HIV. An estimated 0.8% (0.6%-0.9%) of adults aged 15-49 years worldwide is living with HIV. The World Health Organization (WHO) reported that the African region remains most severely affected, with nearly one in every 25 adults (4.1%) living with HIV and accounting for nearly two-thirds of the people living with HIV worldwide. WHO reported that globally only 21.7 million (19.1 million-22.6 million) people have had access to antiretroviral therapy up to 2017. Currently, antiretroviral therapy (ART) is available for the control of HIV but has serious associated side effects such as lipodystrophy. Because of the limitations, associated with ART, researchers throughout the world are trying to explore and develop more reliable and safe drugs from natural resources to manage HIV infection. A wide range of medicinal plants have been studied and have reported significant potential against HIV. Plants like Rheum palmatum L., Rheum officinale, Trigonostem axyphophylloides, Vatica astrotricha, Vernonia amygdalina, Hypoxias pelargonium, Sidoides hemerocallidea and Sutherlandia frutescens etc. have high efficacy to cure HIV. The exact mechanism of action is still not known but various phytoconstituents isolated from medicinal plants such as alkaloids, flavonoids, polyphenols, terpenoids, tannins, proteins and coumarins have the potential to interrupt the life cycle of HIV as well as act as immunomodulators to enhance the immune system of infected patients with no well reported side effects. It could be concluded that medicinal plants have potential for the management of HIV/AIDS but more studies are needed to reveal rigorous efficacy and safety concerns by conducting clinical trials at vast level to explore therapeutic impact of medicinal plants.

Integrase Inhibitors: After 10 Years of Experience, Is the Best Yet to Come?

The era of the integrase strand transfer inhibitors (INSTIs) for the treatment of human immunodeficiency virus (HIV) infection began with raltegravir in 2007. Since that time, several other INSTIs have been introduced including elvitegravir, dolutegravir, and, most recently, bictegravir, that have shown great utility as part of antiretroviral regimens in both treatment-naive and treatment-experienced patients. At present, antiretroviral guidelines fully endorse the INSTI class as part of all first-line treatment regimens. After 10 years of experience with INSTIs, newer agents are on the horizon such as cabotegravir and MK-2048 for potential use as either HIV pre-exposure prophylaxis or maintenance therapy. This review provides a brief overview of the INSTI class including agents currently available and those still in development, reviews available data from both completed and ongoing clinical trials, and outlines simplification strategies using INSTIs.

Efficacy of single-tablet darunavir, cobicistat, emtricitabine, and tenofovir alafenamide in the treatment of HIV-1

INTRODUCTION

HIV eradication is not feasible and lifelong treatment is warranted to manage HIV infection. In this scenario, the advent of single-tablet, once-daily, fixed-dose co-formulations is important for reducing pill burden and maximize long-term drug adherence. Cobicistat-boosted darunavir along with emtricitabine and tenofovir alafenamide co-formulation (DRV/c/FTC/TAF or the trade name Symtuza®) is the first marketed protease inhibitor-based fixed-dose combination regimen for the treatment of HIV infection. It was approved in late 2017 by the European Medical Agency both for naïve patients and treatment-experienced patients with viral suppression. Areas covered: PubMed, ClinicalTrials.gov and presentations at scientific meetings were searched with the terms 'darunavir/cobicistat' and 'tenofovir alafenamide and emtricitabine' for clinical trials either conducted to date or ongoing as well as a review of abstracts from major HIV/AIDS and infectious diseases conferences from 2015 to up to date. Expert opinion: DRV/c/FTC/TAF is a novel unique antiretroviral drug co-formulation that exhibits a convenient dosing, satisfactory safety profile, and high antiviral efficacy, even in patients harboring viruses with resistance to antivirals other than darunavir in the short-midterm. It represents the first fixed-dose combination therapy including a protease inhibitor given as one single pill once daily for drug-naïve patients and as second-line antiretroviral therapy.

Deciphering natural control of HIV-1: A valuable strategy to achieve antiretroviral therapy termination

Antiretroviral therapy (ART) has dramatically reduced HIV-1-associated morbidity and mortality, and has transformed HIV-1 infection into a manageable chronic condition by suppressing viral replication. However, despite recent patient care improvements, ART still fails to cure HIV-1 infection due to the inability to counteract immune defects and metabolic disturbances that are associated with residual inflammation alongside viral persistence. Life-long drug administration also results in multiple side-effects in patients including lipodystrophy and insulin resistance. Thus, it is critical to find new ways to reduce the length of treatment and facilitate the termination of ART, for example by boosting protective immunity. The rare ability of some individuals to naturally control HIV-1 infection despite residual inflammation could be exploited to identify molecular mechanisms involved in host protection that may function as potential therapeutic targets. In this review, we highlight evidence illustrating the molecular and metabolic advantages of HIV-1 controllers over ART treated patients that contribute to the maintenance of effective antiviral immunity.