In vitro susceptibility of CRF02_AG to fostemsavir Francesco - - PowerPoint PPT Presentation

AREVIR MEETING, KÖLN MAY 4-5, 2018

In vitro susceptibility of CRF02_AG to fostemsavir

Francesco Saladini, PhD Department of Medical Biotechnologies University of Siena, Italy

Fostemsavir - overview

Fostemsavir (BMS-663068) Temsavir (BMS-626529)

Gastrointestinal lumen Alcaline phosphatase

Prodrug Active moiety Blood plasma

Fostemsavir - overview

Langley et al., Proteins 2014

Fostemsavir - In vitro antiviral activity

Nowicka-Sans et al., AAC 2012

Subtype B, n. 40

• n. 13
• n. 11
• n. 8
• n. 16

Susceptibility to BMS-626529 of clinical isolates in PBMCs

Fostemsavir - In vitro antiviral activity

Susceptibility to BMS-626529 of pseudotyped viruses in Phenosense Entry Assay

Subtype (n) Median IC50 (nM) IC50 range (nM) A (33) 2.26 0.38 - >100 B (133) 0.34 0.05 - >100 C (36) 1.3 0.07 - >100

CRF01_AE (5)

>100 >100 F (3) 0.1 0.06 – 0.4 F1 (4) 3.75 0.84 – 16 CRF_BF (15) 3.09 0.26 - >100

CRF02_AG (3)

1.77 1.67 – 2.98

Due to natural polymorphisms S375H – M475I?

Nowicka-Sans et al., AAC 2012

Fostemsavir - In vitro antiviral activity

Susceptibility to BMS-626529 of clinical isolates in PBMCs Susceptibility to BMS-626529 of pseudotyped viruses in Phenosense Entry Assay Nowicka-Sans et al., AAC 2012

In vitro susceptibility of CRF02_AG to fostemsavir

A1 1% CRF28_BF 1% CRF43_02G 1% CRF36_cpx 1% CRF31_BC 1% C 2% CRF01_AE 2% F1 4%

CRF02_AG 5%

B 78%

Other 4% A1 CRF28_BF CRF43_02G CRF36_cpx CRF31_BC C CRF01_AE F1 CRF02_AG B Altri

CRF02_AG is the second most prevalent subtype circulating in Italy (ARCA database, www.dbarca.net)

In vitro susceptibility of CRF02_AG to fostemsavir

https://spread.crp-sante.lu/public/subtype

In vitro susceptibility of CRF02_AG to fostemsavir Production of pseudotyped viruses

Generation of CMV-ENV PCR fragments from 14 CRF02_AG strains + NL4-3 (X4- tropic) and AD8 (R5-tropic) Production of pseudotyped viral particles Determination of coreceptor usage and measurement of susceptibility to Temsavir in U87-CXCR4 and/or -CCR5 cells

Lin et al., JVM 2010

In vitro susceptibility of CRF02_AG to fostemsavir Detection of Temsavir RAMs in CRF02_AG Env sequences

In vitro/vivo RAMs selected by Temsavir*: L116P, A204D, S375I/N, M426L, M434I, M475I, V506M

ID sample L116P A204D S375I/N M426L M434I M475I V506M 147290 L A S P M M V 150235 L A S M M M V 146886 L T S M M M V 146733 L T S M M M V 138460 L A S M M M V 142972 L A S M I M V 139179 L A S M M M V 134352 L A S M M M/I V 146996 L A/V S M M M V 139188 L A S M M M V 148738 L A S M M M V 134039 L A S M M/K M V 149856 L A S M M M V 135576 Not available

Rare variants not selected by Temsavir:

• 204T/V e 426P in 0/187 LANL

CRF02_AG sequences

• M434K in 1/187 LANL CRF02_AG

sequences (0.5%) Temsavir RAMs:

• 434I in 31/187 LANL CRF02_AG

sequences (16.6%)

• 475I in 2/187 LANL CRF02_AG

sequences (1.1%)

* Ray et al. JAIDS 2013; Zhou et al. JAC 2014

In vitro susceptibility of CRF02_AG to fostemsavir Determination of coreceptor usage

ID sample Infection U87-CXCR4 Infection U87-CCR5 Tropism FPR 147290 YES YES DUAL 150235 YES YES DUAL 0.8 134352 YES YES DUAL 0.1 146886 NO YES R5 11.4 146733 NO YES R5 12.0 138460 NO YES R5 84.9 142972 NO YES R5 19.1 139179 NO YES R5 9.0 146996 NO YES R5 23.6 139188 NO YES R5 9.0 148738 NO YES R5 26.9 149856 NO YES R5 92.9 135576 NO YES R5 83.0 134039 NO YES R5 99.4 AD8 NO YES R5 35.3 NL4-3 YES NO X4 0.5

Temsavir susceptibility testing on:

• Both U87-CXCR4/U87-

CCR5 cell lines

• U87-CCR5 cell line only
• U87-CXCR4 cell line only

In vitro susceptibility of CRF02_AG to fostemsavir Determination of susceptibility to Temsavir

CRF02_AG Median IC50: 11.9 nM (IQR 2.4-22.6 nM) Range IC50: 0.6 – 381.6 nM Median FC: 6.4 (IQR 1.4-11.0)

ID sample Tropism Mean IC50 (nM) ± SD 147290 DUAL 267.1 ± 162.0 (X4: 152.5; R5: 381.6) 150235 DUAL 24.1 ± 3.2 (X4: 26.3; R5: 21.8) 134352 DUAL 16.7 ± 6.9 (X4: 11.8; R5: 21.5) 146886 R5 0.9 ± 0.5 146733 R5 5.4 ± 6.8 138460 R5 3.4 ± 0.9 142972 R5 0.6 ± 0.4 139179 R5 16.6 ± 4.1 146996 R5 31.6 ± 19.3 139188 R5 15.7 ± 12.5 148738 R5 8.1 ± 4.1 149856 R5 33.6 ± 9.2 135576 R5 2.1 ± 2.8 134039 R5 1.7 ± 1.8 AD8 R5 2.4 ± 1.9 NL4-3 X4 2.4 ± 1.2

In vitro susceptibility of CRF02_AG to fostemsavir Determination of susceptibility to Temsavir

ID sample Tropism Substitution Mean IC50 (nM) ± SD FC 147290 DUAL M426P 267.1 ± 162.0 (X4: 152.5; R5: 381.6) 111.3 Strain/clone LANL frequency % IC50 ± SD nM (FC) FC HIV-1 LAI NL4-3 (426M) 93.6 2.4 ± 1.2 NL4-3 + 426P 9.9 ± 0.8 (4.1) 6.1* NL4-3 + 426L 4.8 44.2 ± 6.3 (18.4) 81# NL4-3 + 426K 0.5 3.7 ± 0.3 (1.5) / NL4-3 + 426R 0.5 1.1 ± 0.3 (0.5) 0.9* ID sample L116P A204D M426L M434I M475I V506M Mean IC50 (nM) ± SD FC 146886 L T M M M V 0.9 ± 0.5 0.4 146733 L T M M M V 5.4 ± 6.8 2.3 142972 L A M I M V 0.6 ± 0.4 0.3 134352 L A M M M/I V 16.7 ± 6.9 (X4: 11.8; R5: 21.5) 7.0 146996 L A/V M M M V 31.6 ± 19.3 13.2 134039 L A M M/K M V 1.7 ± 1.8 0.7

Site-directed mutagenesis on NL4-3 strain Samples with variants at Temsavir RAMs CRF02_AG Median IC50: 11.9 nM - Median FC: 6.4

*Lataillade et al.

#Zhou et al.

Conclusions

• The distribution of IC50 values for CRF02_AG is similar to other subtypes

– Wide range of IC50 values (0.6 – 381.6 nM) – Median FC 6.4 close to previous data obtained with only 3 isolates (FC 5.2, Nowicka-Sans et al.)

• One strain with IC50 > 100 nM: what is the impact in vivo?

– Phase 2 AI438-006 study: 4/10 patients with IC50 >100 nM have <1 log HIV-1 RNA decrease during fostemsavir monotherapy (Nettles et al., JID 2012) – By contrast, one patient with IC50 6.6 μM has >1 log HIV-1 RNA decrease

• Is it necessary to predict/measure fostemsavir activity?

– Is it possible to predict fostemsavir susceptibility through genotypic assays? – Will there be renewed interest in phenotypic testing?

• Phase 2b clinical trial AI438-011 excluded patients with virus showing IC50 >100 nM

(Lataillade et al., JAIDS 2017)

• Phase 3 clinical trial AI438-047 (BRIGHTE Study, NCT02362503) had no cutoff IC50

value for inclusion

THANK YOU FOR YOUR ATTENTION!

• Prof. Maurizio Zazzi research team:

Ilaria Vicenti Alessia Giannini Adele Boccuto Filippo Dragoni

Fostemsavir overview

London, UK 27 October 2017 – ViiV Healthcare, the global specialist HIV company majority owned by GSK, with Pfizer Inc. and Shionogi Limited as shareholders, today announced results from the phase III BRIGHTE study of fostemsavir in heavily treatment-experienced (HTE) patients with HIV-1

• infection. Following one week of treatment, HTE patients receiving fostemsavir added to a failing regimen experienced a greater reduction in HIV-1 viral

load compared to patients receiving placebo, demonstrating statistical superiority of fostemsavir over placebo (0.79 log10 c/mL vs 0.17 log10 c/mL; p<0.0001). After one week of blinded, randomised treatment, all patients received fostemsavir and an optimised background regimen. 54% of patients in the randomised cohort achieved virologic suppression (<40 c/mL) at 24 weeks of treatment with fostemsavir plus optimised background therapy. Most patients who received fostemsavir experienced at least one adverse event by week 24; the most frequently reported Grade 2-4 adverse events related to fostemsavir treatment were transient headache (2%), diarrhoea (2%) and nausea (4%). “The results of the BRIGHTE study are very promising. Patients who participated in this study were failing their current antiretroviral regimens and had very limited treatment options left upon entry into the study, and the addition of fostemsavir to their failing regimen resulted in meaningful reductions in viral load at one week.” said John C Pottage, Jr, MD, Chief Scientific and Medical Officer, ViiV Healthcare. “Fostemsavir is a first-in-class attachment inhibitor, specifically developed for heavily treatment-experienced patients and is representative of ViiV Healthcare’s commitment to developing innovative medicines for all people living with HIV”. Following ViiV Healthcare’s acquisition of fostemsavir, manufacturing is being transitioned to GSK sites, and plans for regulatory submissions will be dependent on collection of data required to support this change. Regulatory submissions are currently anticipated to take place in the 2019/2020 timeframe. The adverse events and serious adverse events reported in the BRIGHTE study were generally reflective of the study population’s advanced disease state (severely immune-compromised with median BL CD4= 80 cells/µ). Seventeen deaths occurred by the week 24 database lock; most related to progression

• f AIDS.

BRIGHTE (NCT02362503) is a two-cohort (Randomised and Non-Randomised), phase 3 clinical trial evaluating the safety and efficacy of the HIV-1 attachment inhibitor fostemsavir in heavily treatment-experienced adults with HIV-1 infection. 371 enrolled patients had documented resistance, intolerability, and/or contraindication to all antiretroviral (ARV) agents in at least four of the six available ARV classes. Patients in the Randomised Cohort had to have one but no more than two fully active ARV classes remaining at baseline and were unable to form a viable antiretroviral regimen out of their remaining agents. These patients were randomised 3:1 to add blinded fostemsavir or blinded placebo (n=272) to their current failing regimen for eight days of functional monotherapy. Patients without any remaining fully active approved ARVs (n=99) were assigned to the Non-Randomised Cohort and received open-label fostemsavir plus optimised background therapy on Day 1. The primary endpoint of the study was mean change in log10 HIV-1 RNA between Day 1 and Day 8 for the Randomised Cohort. Beyond the eight-day blinded period, all patients in the Randomised Cohort received open-label fostemsavir plus optimised background therapy. Key secondary endpoints include durability of response at Weeks 24, 48 and 96, as well as safety and emergence of viral resistance.