Saquinavir Loaded Acetalated Dextran Microconfetti - a Long Acting Protease Inhibitor Injectable

PURPOSE

Since the adoption of highly active antiretroviral therapy, HIV disease progression has slowed across the world; however, patients are often required to take multiple medications daily of poorly bioavailable drugs via the oral route, leading to gastrointestinal irritation. Recently, long acting antiretroviral injectables that deliver drug for months at a time have moved into late phase clinical trials. Unfortunately, these solid phase crystal formulations have inherent drawbacks in potential dose dumping and a greater likelihood for burst release of drug compared to polymeric formulations.

METHODS

Using electrospinning, acetalated dextran scaffolds containing the protease inhibitor saquinavir were created. Grinding techniques were then used to process these scaffolds into injectables which are termed saquinavir microconfetti. Microconfetti was analyzed for in vitro and in vivo release kinetics.

RESULTS

Highly saquinavir loaded acetalated dextran electrospun fibers were able to be formed and processed into saquinavir microconfetti while other polymers such as poly lactic-co-glycolic acid and polycaprolactone were unable to do so. Saquinavir microconfetti release kinetics were able to be tuned via drug loading and polymer degradation rates. In vivo, a single subcutaneous injection of saquinavir microconfetti released drug for greater than a week with large tissue retention.

CONCLUSIONS

Microconfetti is a uniquely tunable long acting injectable that would reduce the formation of adherence related HIV resistance. Our findings suggest that the injectable microconfetti delivery system could be used for long acting controlled release of saquinavir and other hydrophobic small molecule drugs.

Safety and efficacy of a double-boosted protease inhibitor combination, saquinavir and lopinavir/ ritonavir, in pretreated children at 96 weeks

Background

This study aimed to assess the long-term efficacy, safety and use of therapeutic drug monitoring (TDM) of a double-boosted protease inhibitor (PI) combination, saquinavir (SQV) and lopinavir/ritonavir (LPV/r), in Thai HIV type-1 (HIV-1)-infected children who had failed on reverse transcriptase inhibitors.

Methods

In total, 50 children from two sites in Thailand were treated with standard dosing of SQV and LPV/r. CD4+ T-cell count and percentage, viral load (VL; HIV-1 RNA), minimum plasma drug concentrations (Cmin) and drug safety laboratory evaluations were monitored. Virological failure was defined as having two consecutive VL measures >400 copies/ml after week 12. An intention-to-treat analysis was performed.

Results

Baseline data were a median age of 9.3 years (interquartile range [IQR] 7.1–11.2), VL 4.8 log10 copies/ ml (IQR 4.5–5.1) and CD4+ T-cell percentage 7% (IQR 3.0– 9.5). CDC classifications were N=4%, A=14%, B=68% and C=14% of participants. Median CD4+ T-cell percentage and CD4+ T-cell count increase were 14% (IQR 7–19) and 558 cells/mm3 (IQR 308–782), respectively (both P<0.001). Overall, 37 (74%) children achieved VL<50 copies/ml with significant differences between sites (90% versus 63%). Over 96 weeks, 10 patients had virological failure. Total cholesterol and high-density lipoprotein increased significantly over time, whereas the triglycerides and low-density lipoprotein did not. Approximately 50% of participants reported no change in body shape, and 33%, 43% and 39% reported fatter arms, face and abdomen, respectively. LPV and SQV Cmin were high and stable over time.

Conclusions

Double-boosted SQV+LPV/r was an effective and safe alternative for a second-line regimen in children. Hypercholesterolaemia needs close follow-up. On the basis of the TDM results, PI dose reduction in this population should be considered.

Long-Term Efficacy and Safety of First-Line Therapy with Once-Daily Saquinavir/Ritonavir

Background

The aim of this study was to assess the long-term efficacy and safety of first-line treatment with once-daily saquinavir/ritonavir plus two nucleoside reverse transcriptase inhibitors (NRTIs).

Methods

A total of 272 antiretroviral-naive patients with a CD4+ T-cell count of 200–350 cells/mm3 were treated with two NRTIs and saquinavir/ritonavir 1,600/100 mg per day for ≥24 weeks. Patients were followed up every 12 weeks for CD4+ T-cell counts, HIV RNA levels, clinical and laboratory toxicities. Intention-to-treat analyses were used for the first 24 weeks of treatment and as-treated analysis after week 24.

Results

The median baseline CD4+ T-cell count was 269 cells/mm3 and HIV RNA was 4.7 log10 copies/ml. At a median follow-up time of 56 (interquartile range [IQR] 25–113) weeks, 262/272 (96.3%) had HIV RNA <400 copies/ml, with a median HIV RNA decline of -2.89 (IQR 3.31–2.37) log10 copies/ml ( P<0.001) and a median rise in CD4+ T-cell count of 192 (IQR 117–317) cells ( P<0.001). At weeks 24, 48, 72 and 96, 249/272 (91.5%), 157/164 (95.7%), 113/126 (89.7%) and 84/90 (93.3%) had HIV RNA <400 copies/ml, respectively; at the same time points, 83.8%, 92.7%, 85.7% and 85.6% had HIV RNA <50 copies/ml. Drug-related adverse events were reported in 6.3%. Significant rises in total cholesterol, triglyceride, low-density lipoprotein and high-density lipoprotein were seen.

Conclusion

First-line highly active antiretroviral therapy with once-daily saquinavir/ritonavir plus two NRTIs showed strong antiviral efficacy.