European Commission Approves Gilead’s VitektaTM, an Integrase Inhibitor for the Treatment of HIV-1 Infection

Elvitegravir

697761-98-1 CAS

FOSTER CITY, Calif.–(BUSINESS WIRE)–Nov. 18, 2013– Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the European Commission has granted marketing authorization for VitektaTM (elvitegravir 85 mg and 150 mg) tablets, an integrase inhibitor for the treatment of HIV-1 infection in adults without known mutations associated with resistance to elvitegravir. Vitekta is indicated for use as part of HIV treatment regimens that include a ritonavir-boosted protease inhibitor.http://www.pharmalive.com/eu-oks-gileads-vitekta Vitekta interferes with HIV replication by blocking the virus from integrating into the genetic material of human cells. In clinical trials, Vitekta was effective in suppressing HIV among patients with drug-resistant strains of HIV.http://www.pharmalive.com/eu-oks-gileads-vitekta

Elvitegravir (EVG, formerly GS-9137) is a drug used for the treatment of HIV infection. It acts as an integrase inhibitor. It was developed^[1] by the pharmaceutical company Gilead Sciences, which licensed EVG from Japan Tobacco in March 2008.^[2][3][4] The drug gained approval by U.S. Food and Drug Administration on August 27, 2012 for use in adult patients starting HIV treatment for the first time as part of the fixed dose combination known as Stribild.^[5]

According to the results of the phase II clinical trial, patients taking once-daily elvitegravir boosted by ritonavir had greater reductions in viral load after 24 weeks compared to individuals randomized to receive a ritonavir-boosted protease inhibitor.^[6]

 Human immunodeficiency virus type 1 (HIV-1) is the causative agent of acquired immunodeficiency disease syndrome (AIDS).  After over 26 years of efforts, there is still not a therapeutic cure or an effective vaccine against HIV/AIDS.  The clinical management of HIV-1 infected people largely relies on antiretroviral therapy (ART).  Although highly active antiretroviral therapy (HAART) has provided an effective way to treat AIDS patients, the huge burden of ART in developing countries, together with the increasing incidence of drug resistant viruses among treated people, calls for continuous efforts for the development of anti-HIV-1 drugs.  Currently, four classes of over 30 licensed antiretrovirals (ARVs) and combination regimens of these ARVs are in use clinically including: reverse transcriptase inhibitors (RTIs) (e.g. nucleoside reverse transcriptase inhibitors, NRTIs; and non-nucleoside reverse transcriptase inhibitors, NNRTIs), protease inhibitors (PIs), integrase inhibitors and entry inhibitors (e.g. fusion inhibitors and CCR5 antagonists).

1.  Gilead Press Release Phase III Clinical Trial of Elvitegravir July 22, 2008
2.  Gilead Press Release Gilead and Japan Tobacco Sign Licensing Agreement for Novel HIV Integrase Inhibitor March 22, 2008
3.  Shimura K, Kodama E, Sakagami Y, et al. (2007). “Broad Anti-Retroviral Activity and Resistance Profile of a Novel Human Immunodeficiency Virus Integrase Inhibitor, Elvitegravir (JTK-303/GS-9137)”. J Virol 82 (2): 764. doi:10.1128/JVI.01534-07. PMC 2224569. PMID 17977962.
4.  Stellbrink HJ (2007). “Antiviral drugs in the treatment of AIDS: what is in the pipeline ?”. Eur. J. Med. Res. 12 (9): 483–95. PMID 17933730.
5.  Sax, P. E.; Dejesus, E.; Mills, A.; Zolopa, A.; Cohen, C.; Wohl, D.; Gallant, J. E.; Liu, H. C.; Zhong, L.; Yale, K.; White, K.; Kearney, B. P.; Szwarcberg, J.; Quirk, E.; Cheng, A. K.; Gs-Us-236-0102 Study, T. (2012). “Co-formulated elvitegravir, cobicistat, emtricitabine, and tenofovir versus co-formulated efavirenz, emtricitabine, and tenofovir for initial treatment of HIV-1 infection: A randomised, double-blind, phase 3 trial, analysis of results after 48 weeks”.The Lancet 379 (9835): 2439–2448. doi:10.1016/S0140-6736(12)60917-9. PMID 22748591. edit
6.  Thaczuk, Derek and Carter, Michael. ICAAC: Best response to elvitegravir seen when used with T-20 and other active agents Aidsmap.com. 19 Sept. 2007.

 

 The life cycle of HIV-1.  1. HIV-1 gp120 binds to CD4 and co-receptor CCR5/CXCR4 on target cell; 2. HIV-1 gp41 mediates fusion with target cell; 3. Nucleocapsid containing viral genome and enzymes enters cells; 4. Viral genome and enzymes are released; 5. Viral reverse transcriptase catalyzes reverse transcription of ssRNA, forming RNA-DNA hybrids; 6. RNA template is degraded by ribonuclease H followed by the synthesis of HIV dsDNA; 7. Viral dsDNA is transported into the nucleus and integrated into the host chromosomal DNA by the viral integrase enzyme; 8. Transcription of proviral DNA into genomic ssRNA and mRNAs formation after processing; 9. Viral RNA is exported to cytoplasm; 10. Synthesis of viral precursor proteins under the catalysis of host-cell ribosomes; 11. Viral protease cleaves the precursors into viral proteins; 12. HIV ssRNA and proteins assemble under host cell membrane, into which gp120 and gp41 are inserted; 13. Membrane of host-cell buds out, forming the viral envelope; 14. Matured viral particle is released

Elvitegravir, also known as GS 9137 or JTK 303, is an investigational new drug and a novel oral integrase inhibitor that is being evaluated for the treatment of HIV-1 infection. After HIVs genetic material is deposited inside a cell, its RNA must be converted (reverse transcribed) into DNA. A viral enzyme called integrase then helps to hide HIVs DNA inside the cell’s DNA. Once this happens, the cell can begin producing genetic material for new viruses. Integrase inhibitors, such as elvitegravir, are designed to block the activity of the integrase enzyme and to prevent HIV DNA from entering healthy cell DNA. Elvitegravir has the chemical name: 6-(3-chloro-2-fluorobenzyl)-1-[(S)-1 -hydroxy -methyl-2- methylpropyl]-7-methoxy-4-oxo-1, 4-dihydroquinoline-3-carboxylic acid and has the following structural formula:

WO 2000040561 , WO 2000040563 and WO 2001098275 disclose 4-oxo-1 , 4-dihydro-3- quinoline which is useful as antiviral agents. WO2004046115 provides certain 4- oxoquinoline compounds that are useful as HIV Integrase inhibitors.

US 7176220 patent discloses elvitegravir, solvate, stereoisomer, tautomer, pharmaceutically acceptable salt thereof or pharmaceutical composition containing them and their method of treatment. The chemistry involved in the above said patent is depicted below in the Scheme A. Scheme-A

Toluene, DIPEA

SOCl₂ ,COCl (S)-(+)-Valinol

Toluene

,4-Difluoro-₅-iodo- benzoic acid

THF

dichlorobis(triphenylphosphine)

palladium argon stream,

Elvitegravir Form ] Elvitegravir (residue) US 7635704 patent discloses certain specific crystalline forms of elvitegravir. The specific crystalline forms are reported to have superior physical and chemical stability compared to other physical forms of the compound. Further, process for the preparation of elvitegravir also disclosed and is depicted below in the Scheme B. The given processes involve the isolation of the intermediates at almost all the stages.

Scheme B

2,

–

Zn THF,

CK Br THF CU “ZnBr dιchlorobis(trιphenylphos

phine)palladium

Elvitegravir WO 2007102499 discloses a compound which is useful as an intermediate for the synthesis of an anti-HIV agent having an integrase-inhibiting activity; a process for production of the compound; and a process for production of an anti-HIV agent using the intermediate.

WO 2009036161 also discloses synthetic processes and synthetic intermediates that can be used to prepare 4-oxoquinolone compounds having useful integrase inhibiting properties.

The said processes are tedious in making and the purity of the final compound is affected because of the number of steps, their isolation, purification etc., thus, there is a need for new synthetic methods for producing elvitegravir which process is cost effective, easy to practice, increase the yield and purity of the final compound, or that eliminate the use of toxic or costly reagents.

US Patent No 7176220 discloses Elvitegravir, solvate, stereoisomer, tautomer, pharmaceutically acceptable salt thereof or pharmaceutical composition containing them and ■ their method of treatment. US Patent No 7635704 discloses Elvitegravir Form II, Form III and processes for their preparation. The process for the preparation of Form Il disclosed in the said patent is mainly by three methods – a) dissolution of Elvitegravir followed by seeding with Form II, b) recrystallisation of Elvitegravir, and c) anti-solvent method.

The process for the preparation of Form III in the said patent is mainly by three methods – a) dissolution of Form Il in isobutyl acetate by heating followed by cooling the reaction mass, b) dissolution of Form Il in isobutyl acetate by heating followed by seeding with Form III, and c) dissolving Form Il in 2-propanol followed by seeding with Form III.

Amorphous materials are becoming more prevalent in the pharmaceutical industry. In order to overcome the solubility and potential bioavailability issues, amorphous solid forms are becoming front-runners. Of special importance is the distinction between amorphous and crystalline forms, as they have differing implications on drug substance stability, as well as drug product stability and efficacy.

An estimated 50% of all drug molecules used in medicinal therapy are administered as salts. A drug substance often has certain suboptimal physicochemical or biopharmaceutical properties that can be overcome by pairing a basic or acidic drug molecule with a counter- ion to create a salt version of the drug. The process is a simple way to modify the properties of a drug with ionizable functional groups to overcome undesirable features of the parent drug. Salt forms of drugs have a large effect on the drugs’ quality, safety, and performance. The properties of salt-forming species significantly affect the pharmaceutical properties of a drug and can greatly benefit chemists and formulators in various facets of drug discovery and development.

chemical synthesis from a carboxylic acid 1 starts after conversion to the acid chloride iodide NIS 2 , and with three condensation 4 . 4 and the amino alcohol 5 addition-elimination reaction occurs 6 , 6 off under alkaline conditions with TBS protected hydroxy get the ring 7 , 7 and zinc reagent 8 Negishi coupling occurs to get 9 , the last 9 hydrolysis and methoxylated

Elvitegravir dimer impurity, WO2011004389A2

Isolation of 1-[(2S)-1-({3-carboxy-6-(3-chloro-2-fluorobenzyl)-1 -[(2S)-I- hydroxy-3-methylbutan-2-yl]-4-oxo-1 , 4-dihydroquinolin-7-yl}oxy)-3- methylbutan-2-yl 6-(3-chloro-2-fluorobenzyl)-7-methoxy-4-oxo-1 , 4-dihydroquinoline-3-carboxylic acid (elvitegravir dimer impurity, 13)

After isolation of the elvitegravir from the mixture of ethyl acetate-hexane, solvent from the filtrate was removed under reduced pressure. The resultant residue purified by column chromatography using a mixture of ethyl acetate-hexane (gradient, 20-80% EtOAc in hexane) as an eluent. Upon concentration of the required fractions, a thick solid was obtained which was further purified on slurry washing with ethyl acetate to get pure elvitegravir dimer impurity (13). The ¹H-NMR, ¹³C-NMR and mass spectral data complies with proposed structure.

¹H-NMR (DMSO-Cf₆, 300 MHz, ppm) – δ 0.79 (m, d=6.3 Hz, 6H, 20 & 2O’)\ 1.18 & 1.20 (d, J=6.3 Hz & J=6.2 Hz, 6H, 21 & 21′)¹, 2.42-2.49 (m, 2H, 19 & 19′), 3.81-3.89 (m, 3H, T & 17’Ha), 3.94-4.01 (m, 1 H, 17’Hb), 4.01 (s, 3H, 23), 4.11 (s, 2H, 7), 4.83-4.85 (m, 3H, 17 & 18′), 5.22 (t, J=4.7 Hz, 1H, OH), 5.41-5.44 (m, 1 H, 18), 6.73-6.78 (t, J=7.1 Hz, 1 H, 1¹)¹‘ ², 6.92-6.98 (t, J=8.0 Hz, 1H, 3′) ¹‘², 7.12-7.22 (m, 2H, 1 & 3), 7.34-7.39 (m, 1H, 2′),

7.45-7.48 (m, 1 H, 2), 7.49, 7.56 (s, 2H, 15 & 15′), 7.99, 8.02 (s, 2H, 9 & 9′), 8.89, 9.01 (s, 2H, 13 & 13′), 15.30, 15.33 (s, 2H, COOH’ & COOH”).

¹³C-NMR (DMSO-Cf₆, 75 MHz, ppm)- δ 18.87, 19.03 (2OC, 20’C), 19.11 , 19.24 (21 C, 21 ‘C), 27.94 (7’C), 28.40 (7C), 28.91 , 30.08 (19C, 19’C), 56.80(23C), 60.11 (17¹C), 63.59 (18C), 66.52 (18’C), 68.53 (17C), 97.86, 98.97 (15, 15′), 107.43, 108.16 (12C, 12’C),

118.77, 119.38 (1OC, 10’C), 119.57 (d, J=17.6 Hz, 4¹C), 119.61 (d, J=17.9 Hz, 4C),

124.88 (d, J=4.3 Hz, 3¹C), 125.18 (d, J=4.2 Hz, 3C), 126.59, 126.96 (9C₁ 9’C), 127.14 (8’C), 127.62 (d, J=15.9 Hz, 6¹C), 127.73 (8C), 127.99 (d, J=15.2 Hz, 6C), 128.66 (2’C),

128.84 (1¹C), 128.84 (2C), 130.03 (d, J=3.4 Hz, 1C), 142.14, 142.44 (14C, 14’C), 144.37, 145.56 (13C, 13¹C), 155.24 (d, J=245.1 Hz, 5’C)₁ 155.61 (d, J=245.1 Hz, 5C),

160.17 (16’C), 162.04 (16C), 166.00, 166.14 (22C, 22’C), 176.17, 176.22 (11C, 11¹C).

DIP MS: m/z (%)- 863 [M+H]⁺, 885 [M+Na]⁺.