New Drug Approvals

Home » Uncategorized » Cobicistat – European Commission Approves Gilead Sciences’ TybostTM, a New Boosting Agent for HIV Therapy

Cobicistat – European Commission Approves Gilead Sciences’ TybostTM, a New Boosting Agent for HIV Therapy



Read all about Organic Spectroscopy on ORGANIC SPECTROSCOPY INTERNATIONAL 


Recent Posts

Blog Stats

  • 3,947,638 hits

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,725 other followers

add to any




40 H 53 N 7 O 5 S 2


(1,3-thiazol-5-yl) methyl (5S, 8R, 11R) -8,11-dibenzyl-2-methyl-5-[2 – (morpholin-4-yl) ethyl] -1 – [2 – (propan-2-yl) -1,3-thiazol-4-yl] -3,6-dioxo-2 ,4,7,12-tetraazatridecan-13-oate

cytochrome P450 3A4 (CYP3A4) inhibitor

Tybost Facilitates Once-Daily Dosing of the Protease Inhibitors Atazanavir and Darunavir –

FOSTER CITY, Calif.–(BUSINESS WIRE)–Sep. 25, 2013– Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the European Commission has granted marketing authorization for once-daily TybostTM (cobicistat 150 mg tablets), a pharmacokinetic enhancer that boosts blood levels of certain HIV medicines. Tybost is indicated as a boosting agent for the HIV protease inhibitors atazanavir 300 mg once daily and darunavir 800 mg once daily as part of antiretroviral combination therapy in adults with HIV-1 infection. Today’s approval allows for the marketing of Tybost in all 28 countries of the European Union (EU).

read all at

Cobicistat (formerly GS-9350) is a licensed drug for use in the treatment of infection with the human immunodeficiency virus (HIV).

Like ritonavir (Norvir), cobicistat is of interest not for its anti-HIV properties, but rather its ability to inhibit liver enzymes that metabolize other medications used to treat HIV, notablyelvitegravir, an HIV integrase inhibitor currently under investigation itself. By combining cobicistat with elvitegravir, higher concentrations of elvitgravir are achieved in the body with lower dosing, theoretically enhancing elvitgravir’s viral suppression while diminishing its adverse side-effects. In contrast with ritonavir, the only currently approved booster, cobicistat has no anti-HIV activity of its own.[1]

Cobicistat is a component of the four-drug, fixed-dose combination HIV treatmentelvitegravir/cobicistat/emtricitabine/tenofovir (known as the “Quad Pill” or Stribild).[1][2] The Quad Pill/Stribild was approved by the FDA in August 2012 for use in the United States and is owned by Gilead Sciences.
Cobicistat is a potent inhibitor of cytochrome P450 3A enzymes, including the importantCYP3A4 subtype. It also inhibits intestinal transport proteins, increasing the overall absorption of several HIV medications, including atazanavirdarunavir and tenofovir alafenamide fumarate.[3]


  1.  Highleyman, L. Elvitegravir “Quad” Single-tablet Regimen Shows Continued HIV Suppression at 48 Weeks. HIV and
  2.  R Elion, J Gathe, B Rashbaum, and others. The Single-Tablet Regimen of Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Disoproxil Fumarate (EVG/COBI/FTC/TDF; Quad) Maintains a High Rate of Virologic Suppression, and Cobicistat (COBI) is an Effective Pharmacoenhancer Through 48 Weeks. 50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC 2010). Boston, September 12–15, 2010.
  3. Lepist, E. -I.; Phan, T. K.; Roy, A.; Tong, L.; MacLennan, K.; Murray, B.; Ray, A. S. (2012). “Cobicistat Boosts the Intestinal Absorption of Transport Substrates, Including HIV Protease Inhibitors and GS-7340, in Vitro”Antimicrobial Agents and Chemotherapy 56 (10): 5409–5413. doi:10.1128/AAC.01089-12PMC 3457391PMID 22850510

Quad ® laboratoryGilead Sciences , which funded the two clinical trials that have been published, containing a mixture of three active ingredients:tenofovir ,emtricitabine and a new active antiretroviral elvitegravir , also a CYP3A4 inhibitor called cobicistat.

The chemical structures of some of these HCV inhibitors as reported by numerous sources are provided below:

Figure imgf000091_0001


Figure imgf000092_0001


Figure imgf000092_0002

TMC-435 (TMC-435350)

Figure imgf000092_0003
Figure imgf000093_0001

BMS-650032 (Asunaprevir)

Figure imgf000093_0002


Figure imgf000093_0003


Figure imgf000094_0001

ANA-598 (Setrobuvir)

Figure imgf000094_0002

GS-333126 (GS-9190 or tegobuvir)

Figure imgf000094_0003


Figure imgf000095_0001

Mericitabine (R-4048 or RG7128 or R7128)

Figure imgf000095_0002


Figure imgf000095_0003

filibuvir (PF-00868554)

Figure imgf000096_0001

PSI-7977 (GS-7977)

Figure imgf000096_0002

BMS-790052 (daclatasvir)

Figure imgf000096_0003
Figure imgf000096_0004


Figure imgf000097_0001
Figure imgf000098_0001

[0153] BMS-791 As used herein, BMS-

791325 may also be

Figure imgf000099_0001

See also publications at http://wwwl l/program/’Posters/Abstract680.htm; and For GS-5885, see publications at l/EASL/EASL_68.htm; http://wwwl 097.htm; and

40 H 53 N 7 O 5 S 2


  1. medchemnintabelle says:

    Reblogged this on medchemnintabelle.

  2. Dr. G K A S S Narayan says:

    The structure of tenefovir is shown S-configuration which may be corrected

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.


Follow New Drug Approvals on

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,725 other followers



DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with GLENMARK LIFE SCIENCES LTD, Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 30 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri, Dr T.V. Radhakrishnan and Dr B. K. Kulkarni, etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 30 PLUS year tenure till date June 2021, Around 35 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 9 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 90 Lakh plus views on dozen plus blogs, 233 countries, 7 continents, He makes himself available to all, contact him on +91 9323115463, email, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 33 lakh plus views on New Drug Approvals Blog in 233 countries...... , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc

Personal Links

View Full Profile →



Follow my blog with Bloglovin The title of your home page You could put your verification ID in a comment Or, in its own meta tag Or, as one of your keywords Your content is here. The verification ID will NOT be detected if you put it here.
%d bloggers like this: