Indirect Treatment Comparisons of Lenacapavir Plus Optimized Background Regimen Versus Other Treatments for Multidrug-Resistant Human Immunodeficiency Virus

BACKGROUND/AIMS

Heavily treatment-experienced (HTE) people with human immunodeficiency virus (HIV) (PWH) may not achieve virologic suppression (VS) with combination antiretroviral therapy due to multidrug resistance (MDR), intolerance, and safety concerns. These PWH often receive highly individualized treatment regimens, but these regimens may not enable PWH to achieve VS, thereby halting disease progression. Novel medications are required for treating individuals with MDR HIV. Lenacapavir (LEN), a first-in-class HIV capsid inhibitor, is under investigation for the treatment of HTE individuals with MDR HIV in the phase 2/3 CAPELLA study. This study aimed to compare LEN plus optimized background regimen (OBR) with fostemsavir (FTR) + OBR, ibalizumab (IBA) + OBR, and OBR alone in terms of VS, CD4 cell count change from baseline, immunologic recovery, and discontinuation due to adverse events, using indirect treatment comparisons.

METHODS

A systematic review identified clinical evidence on HIV-1 treatments in HTE PWH. A feasibility assessment evaluated the identified studies for indirect treatment comparison analyses based on population characteristics, interventions, comparators, and outcomes of interest. Unanchored simulated treatment comparisons of LEN + OBR versus comparators were conducted.

RESULTS

LEN + OBR had 6.57 times higher odds of VS at weeks 24 to 28 than FTR + OBR (95% confidence interval [CI] 1.34-32.28), 8.93 times higher odds of VS than IBA + OBR (95% CI 2.07-38.46), and 12.74 times higher odds of VS than OBR alone (95% CI 1.70-95.37). Change from baseline in CD4 cell count was similar across LEN + OBR, FTR + OBR, and IBA + OBR.

CONCLUSION

LEN + OBR has statistically significantly greater odds of VS at weeks 24 to 28 than its comparators and represents a novel treatment for people with MDR HIV.

Clinical and Economic Impact of Ibalizumab for People With Multidrug-Resistant HIV in the United States

BACKGROUND

We projected the clinical outcomes, cost-effectiveness, and budget impact of ibalizumab plus an optimized background regimen (OBR) for people with multidrug-resistant (MDR) HIV in the United States.

METHODS

Using the Cost-Effectiveness of Preventing AIDS Complications microsimulation model and a health care sector perspective, we compared 2 treatment strategies for MDR HIV: (1) IBA + OBR-ibalizumab plus OBR and (2) OBR-OBR alone. Ibalizumab efficacy and cohort characteristics were from trial data: mean age 49 years, 85% male, and mean CD4 150/µL. Six-month viral suppression was 50% with IBA + OBR and 0% with OBR. The ibalizumab loading dose cost $10,500, and subsequent ibalizumab injections cost $8400/month; OBR cost $4500/month. Incremental cost-effectiveness ratios (ICERs) were calculated using discounted (3%/year) quality-adjusted life years (QALYs) and costs. ICERs ≤$100,000/QALY were considered cost-effective. We performed sensitivity analysis on key parameters and examined budget impact.

RESULTS

In the base case, 5-year survival increased from 38% with OBR to 47% with IBA + OBR. Lifetime costs were $301,700/person with OBR and $661,800/person with IBA + OBR; the ICER for IBA + OBR compared with OBR was $260,900/QALY. IBA + OBR was not cost-effective even with 100% efficacy. IBA + OBR became cost-effective at base case efficacy if ibalizumab cost was reduced by ≥88%. For an estimated 12,000 people with MDR HIV in the United States, IBA + OBR increased care costs by $1.8 billion (1.5% of total treatment budget) over 5 years.

CONCLUSIONS

For people with MDR HIV lacking other treatment options, ibalizumab will substantially increase survival when effective. Although adding ibalizumab to OBR is not cost-effective, the low number of eligible patients in the United States makes the budget impact relatively small.

Drug resistance and tropism as markers of the dynamics of HIV-1 DNA quasispecies in blood cells of heavily pretreated patients who achieved sustained virological suppression

OBJECTIVES

The objective of this study was to address the dynamics of archived resistant quasispecies in cell-associated HIV-1 DNA over time in heavily ART-experienced patients with currently suppressed plasma HIV-1 RNA.

METHODS

Longitudinal ultra-deep sequencing (UDS) analysis of reverse transcriptase, protease and V3 Env regions was performed on blood-cell-associated HIV-1 DNA samples. Drug-resistance-associated mutations (DRAMs) and tropism were interpreted using the ANRS and Geno2Pheno algorithms. We analysed frozen blood cells from patients enrolled in the INNOVE and ANRS 123 ETOILE studies who achieved sustained viral suppression after salvage optimized ART (SOT).

RESULTS

Samples were available at baseline and 6 and ≥12 months after SOT initiation in 10 patients. V3 loop sequences displayed wide intra-individual dynamics over time. Viral variants harbouring DRAMs exhibited three non-exclusive scenarios. First, when SOT exerted the same selective pressure as previous failing regimens, some viral quasispecies still harboured the same DRAMs at the same level as at the time of virological failure. Thus, as DRAMs were mostly associated with the same viral variant, variants with a complete resistance pattern remained archived. Second, some viral variants harbouring DRAMs were no longer detected over time when SOT consisted of new antiretroviral classes or had resistance profiles distinct from those of previous failing regimens. Third, variants with new DRAMs associated with SOT emerged in blood cells during follow-up despite sustained virological control.

CONCLUSIONS

Using longitudinal UDS analysis and focusing on DRAMs and tropism as markers, we demonstrated that, despite sustained virological control, archived HIV-1 DNA quasispecies continued to evolve.