Rosa Sanchez

Discovery of 3-{5-[(6-amino-1H-pyrazolo[3,4-b]pyridine-3-yl)methoxy]-2-chlorophenoxy}-5-chlorobenzonitrile (MK-4965): a potent, orally bioavailable HIV-1 non-nucleoside reverse transcriptase inhibitor with improved potency against key mutant viruses.

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have been shown to be a key component of highly active antiretroviral therapy (HAART). The use of NNRTIs has become part of standard combination antiviral therapies producing clinical outcomes with efficacy comparable to other antiviral regimens. There is, however, a critical issue with the emergence of clinical resistance, and a need has arisen for novel NNRTIs with a broad spectrum of activity against key HIV-1 RT mutations. Using a combination of traditional medicinal chemistry/SAR analyses, crystallography, and molecular modeling, we have designed and synthesized a series of novel, highly potent NNRTIs that possess broad spectrum antiviral activity and good pharmacokinetic profiles. Further refinement of key compounds in this series to optimize physical properties and pharmacokinetics has resulted in the identification of 8e (MK-4965), which has high levels of potency against wild-type and key mutant viruses, excellent oral bioavailability and overall pharmacokinetics, and a clean ancillary profile.

The design and synthesis of diaryl ether second generation HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) with enhanced potency versus key clinical mutations.

Using a combination of traditional Medicinal Chemistry/SAR analysis, crystallography, and molecular modeling, we have designed and synthesized a series of novel, highly potent NNRTIs that possess broad antiviral activity against a number of key clinical mutations.

Biaryl Ethers as Novel Non-nucleoside Reverse Transcriptase Inhibitors with Improved Potency against Key Mutant Viruses

Biaryl ethers were recently reported as potent NNRTIs. Herein we disclose a detailed SAR study that led to the biaryl ether 6. This compound possessed excellent potency against WT RT and key clinically observed RT mutants and had an excellent pharmacokinetic profile in rats, dogs, and rhesus macaques. The compound also exhibited a clean safety profile in preclinical safety studies.

Effect of suberoylanilide hydroxamic acid (SAHA) administration on the residual virus pool in a model of combination antiretroviral therapy-mediated suppression in SIVmac239-infected indian rhesus macaques.

ABSTRACT Nonhuman primate models are needed for evaluations of proposed strategies targeting residual virus that persists in HIV-1-infected individuals receiving suppressive combination antiretroviral therapy (cART). However, relevant nonhuman primate (NHP) models of cART-mediated suppression have proven challenging to develop. We used a novel three-class, six-drug cART regimen to achieve durable 4.0- to 5.5-log reductions in plasma viremia levels and declines in cell-associated viral RNA and DNA in blood and tissues of simian immunodeficiency virus SIVmac239-infected Indian-origin rhesus macaques, then evaluated the impact of treatment with the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA; Vorinostat) on the residual virus pool. Ex vivo SAHA treatment of CD4+ T cells obtained from cART-suppressed animals increased histone acetylation and viral RNA levels in culture supernatants. cART-suppressed animals each received 84 total doses of oral SAHA. We observed SAHA dose-dependent increases in acetylated histones with evidence for sustained modulation as well as refractoriness following prolonged administration. In vivo virologic activity was demonstrated based on the ratio of viral RNA to viral DNA in peripheral blood mononuclear cells, a presumptive measure of viral transcription, which significantly increased in SAHA-treated animals. However, residual virus was readily detected at the end of treatment, suggesting that SAHA alone may be insufficient for viral eradication in the setting of suppressive cART. The effects observed were similar to emerging data for repeat-dose SAHA treatment of HIV-infected individuals on cART, demonstrating the feasibility, utility, and relevance of NHP models of cART-mediated suppression for in vivo assessments of AIDS virus functional cure/eradication approaches.

Substituted tetrahydroquinolines as potent allosteric inhibitors of reverse transcriptase and its key mutants

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are key elements of multidrug regimens, called HAART (Highly Active Antiretroviral Therapy), that are used to treat HIV-1 infections. Elucidation of the structure-activity relationships of the thiocarbamate moiety of the previous published lead compound 2 provided a series of novel tetrahydroquinoline derivatives as potent inhibitors of HIV-1 RT with nanomolar intrinsic activity on the WT and key mutant enzymes and potent antiviral activity in infected cells. The SAR optimization, mutation profiles, preparation of compounds, and pharmacokinetic profile of compounds are described.

Design and synthesis of conformationally constrained inhibitors of non-nucleoside reverse transcriptase.

Highly active antiretroviral therapy (HAART) significantly reduces human immunodeficiency virus (HIV) viral load and has led to a dramatic decrease in acquired immunodeficiency syndrome (AIDS) related mortality. Despite this success, there remains a critical need for new HIV therapies to address the emergence of drug resistant viral strains. Next generation NNRTIs are sought that are effective against these mutant forms of the HIV virus. The bound conformations of our lead inhibitors, MK-1107 (1) and MK-4965 (2), were divergent about the oxymethylene linker, and each of these conformations was rigidified using two isomeric cyclic constraints. The constraint derived from the bioactive conformation of 2provided novel, highly potent NNRTIs that possess broad spectrum antiviral activity and good pharmacokinetic profiles. Systematic SAR led to the identification of indazole as the optimal conformational constraint to provide MK-6186 (3) and MK-7445 (6). Despite their reduced flexibility, these compounds had potency comparable to that of the corresponding acyclic ethers in both recombinant enzyme and cell based assays against both the wild-type and the clinically relevant mutant strains.

Design and synthesis of pyridone inhibitors of non-nucleoside reverse transcriptase.

Next generation NNRTIs are sought which possess both broad spectrum antiviral activity against key mutant strains and a high genetic barrier to the selection of new mutant viral strains. Pyridones were evaluated as an acyclic conformational constraint to replace the aryl ether core of MK-4965 (1) and the more rigid indazole constraint of MK-6186 (2). The resulting pyridone compounds are potent inhibitors of HIV RT and have antiviral activity in cell culture that is superior to other next generation NNRTIs.

Biaryl ethers as potent allosteric inhibitors of reverse transcriptase and its key mutant viruses: Aryl substituted pyrazole as a surrogate for the pyrazolopyridine motif

Biaryl ethers were recently reported as potent NNRTIs. Herein, we disclose a detailed effort to modify the previously reported compound 1. We have designed and synthesized a series of novel pyrazole derivatives as a surrogate for pyrazolopyridine motif that were potent inhibitors of HIV-1 RT with nanomolar intrinsic activity on the WT and key mutant enzymes and potent antiviral activity in infected cells.

Potent, selective and orally bioavailable leucine-rich repeat kinase 2 (LRRK2) inhibitors

Familial Parkinsons disease cases have recently been associated with the leucine rich repeat kinase 2 (LRRK2) gene. It has been hypothesized that inhibition of the LRRK2 protein may have the potential to alter disease pathogenesis. A dihydrobenzothiophene series of potent, selective, orally bioavailable LRRK2 inhibitors were identified from a high-throughput screen of the internal Merck sample collection. Initial SAR studies around the core established the series as a tractable small molecule lead series of LRRK2 inhibitors for potential treatment of Parkinsons disease. It was also found that incorporation of a lactam into the core drastically improved the CNS and DMPK properties of these small molecules.

Epsilon substituted lysinol derivatives as HIV-1 protease inhibitors.

A series of HIV-1 protease inhibitors containing an epsilon substituted lysinol backbone was synthesized. Two novel synthetic routes using N-boc-L-glutamic acid alpha-benzyl ester and 2,6-diaminopimelic acid were developed. Incorporation of this epsilon substituent enabled access to the S2 pocket of the enzyme, affording high potency inhibitors. Modeling studies and synthetic efforts suggest the potency increase is due to both conformational bias and van der Waals interactions with the S2 pocket.