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Background Dysregulation of the Janus kinase (JAK)/signal transducers and activators of transcription pathway contributes to abnormal inflammatory responses and poor prognosis in non–small-cell lung cancer (NSCLC). We evaluated the JAK1/JAK2 inhibitor ruxolitinib plus pemetrexed/cisplatin first-line in patients with stage IIIB/IV or recurrent nonsquamous NSCLC with systemic inflammation (modified Glasgow prognostic score [mGPS] 1/2). Patients and Methods Part 1 was an open-label, safety run-in, in which we assessed ruxolitinib (15 mg twice daily [b.i.d.]) plus pemetrexed (500 mg/m2 intravenous, day 1) and cisplatin (75 mg/m2 intravenous, day 1). Ruxolitinib dose selection for part 2 required Results Fifteen patients enrolled in part 1 (median age, 64 years; 80% male, 80% mGPS 1) received ruxolitinib 15 mg b.i.d. plus pemetrexed/cisplatin. Median treatment duration was 140 days and no DLTs occurred in 11 evaluable patients. No new safety concerns arose when ruxolitinib was combined with pemetrexed/cisplatin. At study termination, 39 patients were randomized to ruxolitinib and 37 to placebo in part 2. Median treatment duration was 43 days. Response rate was 31% (12 of 39) with ruxolitinib and 35% (13 of 37) with placebo (all partial responses). Conclusion Ruxolitinib 15 mg b.i.d. had an acceptable safety profile in combination with pemetrexed/cisplatin asfirst-line treatment of patients with stage IIIB/IV or recurrent nonsquamous NSCLC and systemic inflammation. Early study termination limited the interpretation of efficacy data in the randomized phase II part of the study.

TPS7058 Background: Ruxolitinib (JAK1/JAK2 inhibitor) significantly improves outcomes in patients with myelofibrosis (MF); however, a subset of patients may experience a suboptimal response. Recent phase 2 data showed that addition of PI3Kδ inhibitor parsaclisib to ruxolitinib monotherapy resulted in additional alleviation of MF symptoms and splenomegaly in patients with MF (Yacoub. EHA2020. S216). This phase 3, randomized, double-blind study (INCB 50465-313; NCT04551066), evaluates the combination of ruxolitinib and parsaclisib in patients with MF who are naïve to Janus kinase (JAK) and PI3K inhibitor therapies. Methods: Eligible patients are aged ≥18 years with a diagnosis of primary MF, post-polycythemia vera MF, or post-essential thrombocythemia MF, have a Dynamic International Prognostic Scoring System (DIPSS; Passamonti. Blood. 2010;115:1703-1708) risk category of at least Intermediate (INT)-1, palpable spleen ≥5 cm below left subcostal margin; total symptom score ≥10 at screening, ECOG PS 0–2, and life expectancy ≥24 weeks. Patients will be excluded if they previously received therapy with any JAK inhibitor, any PI3K inhibitor, any experimental or standard drug therapy for MF ≤3 months of first study dose and/or lack of recovery from all toxicities related to previous therapies to grade ≤1, have recent history of inadequate bone marrow reserve (eg, platelet count = 50×109/L) or have inadequate liver or renal function at screening. Approximately 440 patients will be randomized (1:1) to ruxolitinib plus parsaclisib 5 mg QD or ruxolitinib plus matching placebo, with stratification at randomization by DIPSS risk category (high vs INT-2 vs INT-1) and platelet count (≥100×109/L vs 50 to = 100×109/L inclusive). Treatment will begin on Day 1, with starting ruxolitinib dose level determined by baseline platelet count, and will continue as long as treatment is tolerated and discontinuation criteria are not met. When the last enrolled patient has completed 24 weeks of treatment, the study will be unblinded and patients randomized to ruxolitinib plus placebo who have adequate hematology parameters will be able to crossover to receive parsaclisib together with continued ruxolitinib. The primary objective is the evaluation and comparison of spleen volume at Week 24 for patients who received ruxolitinib plus parsaclisib versus ruxolitinib plus placebo. Secondary objectives include evaluation and comparison of patient-reported MF symptoms, overall survival, time to onset and duration of response in spleen volume, and safety and tolerability for ruxolitinib plus parsaclisib versus ruxolitinib plus placebo. Sites are opening across the United States, Europe, Asia, and New Zealand. Clinical trial information: NCT04551066.

Ruxolitinib improves splenomegaly and symptoms in patients with intermediate-2 or high-risk myelofibrosis; however, nearly half develop grade 3/4 anemia and/or thrombocytopenia, necessitating dose reductions and/or transfusions. We report findings from an open-label phase 2 study exploring a dose-escalation strategy aimed at preserving clinical benefit while reducing hematological adverse events early in ruxolitinib treatment. Patients with myelofibrosis received ruxolitinib 10 mg twice daily (BID), with incremental increases of 5 mg BID at weeks 12 and 18 for lack of efficacy (maximum, 20 mg BID). Symptom severity was measured using the Myelofibrosis Symptom Assessment Form Total Symptom Score (MFSAF TSS). Forty-five patients were enrolled, 68.9% of whom had a Dynamic International Prognostic Scoring System score of 1 to 2 (i.e., intermediate-1 disease risk). Median percentage change in spleen volume from baseline to week 24 was − 17.3% (≥ 10% reduction achieved by 26 patients [57.8%]), with a clear dose response. Median percentage change in MFSAF TSS from baseline at week 24 was − 45.6%, also with a dose response. The most frequent treatment-emergent adverse events were anemia (26.7%), fatigue (22.2%), and arthralgias (20.0%). Grade 3/4 anemia (20.0%) and dose decreases due to anemia (11.1%) or thrombocytopenia (6.7%) were infrequent. A dose-escalation approach may mitigate worsening anemia during early ruxolitinib therapy in some patients with myelofibrosis. ClinicalTrials.gov identifier, NCT01445769 . Registered September 23, 2011.

In the phase III COMFORT-I study, the Janus kinase 1 (JAK1)/JAK2 inhibitor ruxolitinib provided significant improvements in splenomegaly, key symptoms, and quality-of-life measures and was associated with an overall survival benefit relative to placebo in patients with intermediate-2 or high-risk myelofibrosis. This planned analysis assessed the long-term efficacy and safety of ruxolitinib at a median follow-up of 149 weeks. At data cutoff, approximately 50% of patients originally randomized to ruxolitinib remained on treatment whereas all patients originally assigned to placebo had discontinued or crossed over to ruxolitinib. At week 144, mean spleen volume reduction was 34% with ruxolitinib. Previously observed improvements in quality-of-life measures were sustained with longer-term ruxolitinib therapy. Overall survival continued to favor ruxolitinib despite the majority of placebo patients crossing over to ruxolitinib [hazard ratio 0.69 (95% confidence interval: 0.46–1.03); P=0.067]. Exploratory analyses suggest that crossover may have contributed to an underestimation of the true survival difference between the treatment groups. Ruxolitinib continued to be generally well tolerated; there was no pattern of worsening grade ≥3 anemia or thrombocytopenia with longer-term ruxolitinib exposure. These longer-term data continue to support the efficacy and safety of ruxolitinib in patients with myelofibrosis. The study is registered at clinicaltrials.gov: NCT00952289.

Patient-reported outcomes (PROs) and spleen size in patients not receiving therapy (N=154) in COMFORT-I, a randomized, double-blind study of the JAK1/JAK2 inhibitor ruxolitinib in patients with intermediate-2 or high-risk myelofibrosis were evaluated. Baseline PROs indicated considerable disease burden. European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 scores, modified Myelofibrosis Symptom Assessment Form v2.0 Total Symptom Score, and Patient Reported Outcome Measurement Information System Fatigue scores worsened from baseline through week 24. At weeks 4 and 24, 18.3 and 40.2% of patients evaluated their condition as having worsened from baseline on the Patient Global Impression of Change questionnaire. Spleen volume and palpable length increased in most patients. These results demonstrate the progressive and debilitating effects of myelofibrosis. The consequences of delayed intervention should be assessed in the management of patients with myelofibrosis and treatment should be considered as clinically indicated for symptomatic relief or splenomegaly control.

Purpose To assess the effects of ruxolitinib on symptom burden and quality of life (QoL) and to evaluate the ability of the modified Myelofibrosis Symptom Assessment Form (MFSAF) v2.0 to measure meaningful changes in myelofibrosis-related symptoms in patients with myelofibrosis. Patients and Methods COMFORT-I (Controlled Myelofibrosis Study With Oral JAK Inhibitor Treatment–I) is a double-blind, placebo-controlled phase III study evaluating ruxolitinib in patients with intermediate-2 or high-risk myelofibrosis. Exploratory analyses were conducted on the following patient-reported outcomes (PROs) assessments: modified MFSAF v2.0 (individual symptoms and Total Symptom Score [TSS]), European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30), Patient Reported Outcomes Measurement Information System (PROMIS) Fatigue Scale, and Patient Global Impression of Change (PGIC). Results Patients receiving ruxolitinib experienced improvements in individual myelofibrosis-related symptoms, although patients receiving placebo experienced worsening (P < .001). The majority (91%) of ruxolitinib-treated patients designated as ≥ 50% TSS responders (≥ 50% TSS improvement) self-reported their condition as either “Much improved” or “Very much improved” on the PGIC. These patients achieved significant improvements in the EORTC QLQ-C30 functional domains and Global Health Status/QoL versus patients receiving placebo, who experienced worsening on these measures (P ≤ .0135). Ruxolitinib-treated patients with a lesser degree of symptom improvement (< 50% TSS responders) also achieved improvements over placebo on these measures. The degree of spleen volume reduction with ruxolitinib correlated with improvements in TSS, PGIC, PROMIS Fatigue Scale, and EORTC Global Health Status/QoL. Ruxolitinib-treated patients who achieved a ≥ 35% reduction in spleen volume experienced the greatest improvements in these PROs. Conclusion Ruxolitinib-treated patients achieved clinically meaningful improvements in myelofibrosis-related symptoms and QoL, but patients receiving placebo reported worsening of symptoms and other PROs.

Myelofibrosis (MF) is a rare and life-threatening myeloproliferative neoplasm that can arise de novo [primary MF (PMF)] or evolve from polycythaemia vera (PV), i.e. post-polycythaemia vera MF (PPV-MF), or essential thrombocythaemia (ET), i.e. post-ET MF (PET-MF) (Barosi et al, 2008; Vardiman et al, 2009; Tefferi, 2011). Dysregulated Janus kinase/signal transducers and activators of transcription (JAK-STAT) signalling, resulting from gain- or loss-of-function mutations and/or high circulating levels of inflammatory cytokines, plays a key role in the pathogenesis of MF (Vainchenker et al, 2011). The JAK2 V617F mutation is present in approximately 50–60% of patients with PMF or ET and in over 95% of patients with PV (Nguyen & Gotlib, 2012). Dysregulation of the JAK-STAT signalling pathway in MF is additionally related to mutations in genes such as JAK2 exon 12, MPL exon 10, SH2B3, members of the Casitas B-cell lymphoma family and post-translational modifications of suppressor of cytokine signalling proteins (Vainchenker et al, 2011). Proinflammatory cytokines that have been implicated in MF are known to signal through JAK1 and JAK2 (Vainchenker et al, 2008) and symptoms of MF have been linked to elevated levels of these cytokines (Verstovsek, 2009; Tefferi et al, 2011). An association between elevated cytokines and decreased survival has also been reported (Tefferi et al, 2011). A broad spectrum of disease characteristics exists within the MF patient population (Cervantes et al, 1997, 2009). Patients often experience constitutional symptoms (e.g. fever, night sweats, weight loss) and splenomegaly, which may cause disability and have a profound impact on quality of life (Mesa et al, 2007); however, other MF-related symptoms, such as fatigue (84%), itching (50%) and bone pain (47%), are also common and burdensome to patients (Mesa et al, 2007). Patients with MF have shortened survival, and those with advanced MF have a poor prognosis (Barbui et al, 2011). The major prognostic scoring systems used to categorize risk in patients with MF are the International Prognostic Scoring System (IPSS) (Cervantes et al, 2009), the Dynamic International Prognostic Scoring System (DIPSS) (Passamonti et al, 2010) and DIPSS Plus (Gangat et al, 2011). Risk factors for shorter survival in both the IPSS and DIPSS are age >65 years, presence of constitutional symptoms, haemoglobin 25 × 109/l and peripheral blood blasts ≥1% (Cervantes et al, 2009; Passamonti et al, 2010). The DIPSS Plus adds platelet count

Myelofibrosis (MF) is a myeloproliferative neoplasm that is characterized by a series of consequences from the clonal disease.1 Included among the consequences of MF are the development of ineffective hematopoiesis (and thus potentially anemia and other cytopenias), leukoerythroblastosis, splenomegaly through perhaps a variety of mechanisms including (but not limited to) ineffective hematopoiesis and splenic sequestration of immature myeloid cells, significant constitutional symptoms (night sweats, fevers, weight loss), pruritus, risk of blastic transformation, and premature death.2 We have previously demonstrated that the symptomatic burden among patients with MF is significant both from directly observable effects of disease (ie, from anemia and/or splenomegaly) and by self-reported outcomes from MF patients for less quantifiable symptoms such as fatigue, night sweats, and pruritus.3 We have also reported that the prevalence of these symptoms is relatively uniform across the 3 main subtypes of MF (namely, primary MF, post-polycythemia vera MF [post-PV MF], and post-essential thrombocythemia MF [post-ET MF]).4 In addition, the presence of significant constitutional symptoms is not only bothersome for the individual patient, but has been found to be prognostically detrimental and is included as an adverse prognostic factor in the International Working Group for Myelofibrosis Research and Treatment prognostic score for MF.5 Historically, therapies for MF have been largely palliative, with very limited ability to significantly impact the symptomatic burden of patients afflicted with the disease. However, the discovery of the JAK2-V617F mutation in 20056 (and subsequent discovery of related myeloproliferative neoplasm-associated mutations7,8) has ushered in an era of targeted therapeutic approaches for MF including JAK inhibitors,9 which down-modulate the dysregulated activity of JAKs that is characteristic in the myeloproliferative neoplasms. Initial results of these targeted trials demonstrated a profound ability of these medications to decrease MF-associated splenomegaly and symptoms.10,11 The difficulty was that no current instrument of patient-reported outcomes adequately and concisely assessed the spectrum of MF-associated symptoms. Therefore, we developed, and validated in a single time point validation study, the Myelofibrosis Symptom Assessment Form.4 This instrument captured the spectrum of MF-associated constitutional symptoms (fatigue, night sweats, fevers, pruritus, weight loss) and splenomegaly-associated symptoms (abdominal pain, early satiety, mechanical effects from the spleen). This prior validation of the Myelofibrosis Symptom Assessment Form used a series of established instruments of patient-reported outcomes to validate the questions and results obtained from the Myelofibrosis Symptom Assessment Form. In addition, a separate question is asked relating to an overall assessment of quality of life. We sought to evaluate the use of the Myelofibrosis Symptom Assessment Form for measurement of baseline symptoms and sensitivity to detect changes when used serially in clinical trials. Therefore, we used the Myelofibrosis Symptom Assessment Form in serial administrations in conjunction with the largest phase 2 trial ever conducted for that disorder, the open label phase 2 trial of the selective JAK1 and JAK2 inhibitor INCB018424 (Trial 251).10

Myelofibrosis is a Philadelphia chromosome–negative myeloproliferative neoplasm associated with cytopenias, splenomegaly, poor quality of life, and shortened survival. About half of patients with myelofibrosis carry a gain-of-function mutation in the Janus kinase 2 gene (JAK2 V617F) that contributes to the pathophysiology of the disease. INCB018424 is a potent and selective Janus kinase 1 (JAK1) and JAK2 inhibitor.We conducted a phase 1−2 trial of INCB018424 in patients with JAK2 V617F−positive or JAK2 V617F−negative primary myelofibrosis, post–essential thrombocythemia myelofibrosis, or post–polycythemia vera myelofibrosis.A total of 153 patients received INCB018424 for a median duration of more than 14.7 months. The initial dose-escalation phase established 25 mg twice daily or 100 mg once daily as maximum tolerated doses, on the basis of reversible thrombocytopenia. A dose-dependent suppression of phosphorylated signal transducer and activator of transcription 3 (STAT3), a marker of JAK signaling, was demonstrated in patients with wild-type JAK2 and in patients with the JAK2 V617F mutation. We studied additional doses and established that a 15-mg twice-daily starting dose, followed by individualized dose titration, was the most effective and safest dosing regimen. At this dose, 17 of 33 patients (52%) had a rapid objective response (≥50% reduction of splenomegaly) lasting for 12 months or more, and this therapy was associated with grade 3 or grade 4 adverse events (mainly myelosuppression) in less than 10% of patients. Patients with debilitating symptoms, including weight loss, fatigue, night sweats, and pruritus, had rapid improvement. Clinical benefits were associated with a marked diminution of levels of circulating inflammatory cytokines that are commonly elevated in myelofibrosis.INCB018424 was associated with marked and durable clinical benefits in patients with myelofibrosis for whom no approved therapies existed. (Funded by Incyte; ClinicalTrials.gov number, NCT00509899.)

A series of P1/P1' substituted cyclic urea analogues were prepared in an attempt to increase the intra-cellular antiviral potency of the nonsymmetrical 3-aminoindazoles DMP 850 and DMP 851. The effect of alkyl substitution of the P1/P1' residues on cellular antiviral potency, protein binding, resistance profile and pharmacokinetics are described.

A series of peptide boronic acids containing extended, hydrophobic P1 residues was prepared to probe the shallow, hydrophobic S1 region of HCV NS3 protease. The p-trifluoromethylphenethyl P1 substituent was identified as optimal with respect to inhibitor potency for NS3 and selectivity against elastase and chymotrypsin.

Highly active antiretroviral therapy (HAART) is the standard treatment for infection with the human immunodeficiency virus (HIV). HAART regimens consist of protease inhibitors or nonnucleoside reverse transcriptase inhibitors combined with two or more nucleoside reverse transcriptase inhibitors (NRTIs). DPC 817, 2′,3′-didehydro-2′,3′-dideoxy-5-fluorocytidine (PSI 5582 D-D4FC) is a potent inhibitor of HIV type 1 replication in vitro. Importantly, DPC 817 retains activity against isolates harboring mutations in the reverse transcriptase gene that confer resistance to lamivudine (3TC) and zidovudine (AZT), which are frequent components of initial HAART regimens. DPC 817 combines this favorable resistance profile with rapid uptake and conversion to the active metabolite DPC 817-triphosphate, which has an intracellular half-life of 13 to 17 h. Pharmacokinetics in the rhesus monkey suggest low clearance of parent DPC 817 and a plasma half-life longer than that of either AZT or 3TC. Together, these properties suggest that DPC 817 may be useful as a component of HAART regimens in individuals with resistance to older NRTI agents.

Background: Silicon is the element most similar to carbon, and bioactive organosilanes have therefore been of longstanding interest. Design of bioactive organosilanes has often involved a systematic replacement of a bioactive molecule's stable carbon atoms with silicon. Silanediols, which are best known as unstable precursors of the robust and ubiquitous silicone polymers, have the potential to mimic an unstable carbon, the hydrated carbonyl. As a bioisostere of the tetrahedral intermediate of amide hydrolysis, a silanediol could act as a transition state analog inhibitor of protease enzymes. Results: Silanediol analogs of a carbinol-based inhibitor of the HIV protease were prepared as single enantiomers, with up to six stereogenic centers. As inhibitors of this aspartic protease, the silanediols were nearly equivalent to both their carbinol analogs and indinavir, a current treatment for AIDS, with low nanomolar K i values. IC 90 data from a cell culture assay mirrored the K i data, demonstrating that the silanediols can also cross cell membranes and deliver their antiviral effects. Conclusions: In their first evaluation as inhibitors of an aspartic protease, silanediol peptidomimetics have been found to be nearly as potent as currently available pharmaceutical agents, in enzyme and cell protection assays. These neutral, cell-permeable transition state analogs therefore provide a novel foundation for the design of therapeutic agents.

Human immunodeficiency virus (HIV) protease inhibitors (PIs) are important components of many highly active antiretroviral therapy regimens. However, development of phenotypic and/or genotypic resistance can occur, including cross-resistance to other PIs. Development of resistance takes place because trough levels of free drug are inadequate to suppress preexisting resistant mutant variants and/or to inhibit de novo-generated resistant mutant variants. There is thus a need for new PIs, which are more potent against mutant variants of HIV and show higher levels of free drug at the trough. We have optimized a series of substituted sulfonamides and evaluated the inhibitors against laboratory strains and clinical isolates of HIV type 1 (HIV-1), including viruses with mutations in the protease gene. In addition, serum protein binding was determined to estimate total drug requirements for 90% suppression of virus replication (plasma IC90). Two compounds resulting from our studies, designated DPC 681 and DPC 684, are potent and selective inhibitors of HIV protease with IC90s for wild-type HIV-1 of 4 to 40 nM. DPC 681 and DPC 684 showed no loss in potency toward recombinant mutant HIVs with the D30N mutation and a fivefold or smaller loss in potency toward mutant variants with three to five amino acid substitutions. A panel of chimeric viruses constructed from clinical samples from patients who failed PI-containing regimens and containing 5 to 11 mutations, including positions 10, 32, 46, 47, 50, 54, 63, 71, 82, 84, and 90 had mean IC50values of 50values ranging from 200 nM (amprenavir) to >900 nM (nelfinavir).

3-Alkoxymethyl- and 3-aryloxymethyl-2-pyridinones were synthesized and evaluated for activity as non-nucleoside reverse transcriptase inhibitors (NNRTIs) of HIV-1. It was found that several compounds were potent inhibitors of HIV-1 with the most potent compound 24 exhibiting an IC90=32 nM. Compound 24 also possessed a potent resistance profile as demonstrated by submicromolar IC90s against several clinically meaningful mutant virus strains.

A series of unique 3,3a-dihydropyrano[4,3,2-de]quinazolin-2(1H)-ones and a 2a,5-dihydro-2H-thieno[4,3,2-de]quinazoline-4(3H)-thione were found to be HIV-1 non-nucleoside reverse transcriptase inhibitors. One of these compounds, as the racemate, possessed an IC90=4.6 nM against wild-type virus in a whole cell antiviral assay and had an IC90=76 and 897 nM against the clinically significant K103N and K103N/L100I mutant viruses, respectively.

The objective of this study was to determine whether reverse transcriptase inhibitors (RTIs) could decrease viral replication in microglia. Human microglia obtained from individuals undergoing temporal lobectomy were cultured and infected with HIV-1 isolates from the central nervous system (CNS) as previously described (Strizki JM, et al. J Virol 1996;70:7654-7662). These microglial cultures were treated with one of three nucleoside RTIs (NRTIs) or with efavirenz, a nonnucleoside RTI (NNRTI), at various time points before and during HIV-1 infection. The drug levels sufficient to provide90% inhibition of microglial HIV replication (IC90) were determined by comparison of p24(gag) release in the cultures among treated and untreated microglia. Infectious virus released from the infected cultures was also measured with U373-MAGI-CCR5 cells. Efavirenz, an NNRTI, blocked HIV-1(DS-br) infection of microglia with an IC(90) of 0.7-7 nM. This value is similar to the efavirenz IC(90) values for inhibition of laboratory and clinical isolates in lymphocytes, is 2-3 logs lower than the IC90 values of AZT and d4T, and is 1-2 logs lower than that of ddC in microglia. Efavirenz also inhibited infection with other neurotropic isolates, and with viruses isolated from other compartments that also replicated well in microglia. Thus, efavirenz is a potent inhibitor of HIV-1 infection in microglia. Furthermore, efavirenz IC(90) drug levels are present in the cerebrospinal fluid (CSF) of patients taking this once daily NNRTI.

A research program targeted toward the identification of expanded-spectrum nonnucleoside reverse transcriptase inhibitors which possess increased potency toward K103N-containing mutant human immunodeficiency virus (HIV) and which maintain pharmacokinetics consistent with once-a-day dosing has resulted in the identification of the 4-cyclopropylalkynyl-4-trifluoromethyl-3,4-dihydro-2(1 H )quinazolinones DPC 961 and DPC 963 and the 4-cyclopropylalkenyl-4-trifluoromethyl-3,4-dihydro-2(1 H )quinazolinones DPC 082 and DPC 083 for clinical development. DPC 961, DPC 963, DPC 082, and DPC 083 all exhibit low-nanomolar potency toward wild-type virus, K103N and L100I single-mutation variants, and many multiply amino acid-substituted HIV type 1 mutants. This high degree of potency is combined with a high degree of oral bioavailability, as demonstrated in rhesus monkeys and chimpanzees, and with plasma serum protein binding that can result in significant free levels of drug.

The preparation of unsymmetrical cyclic ureas bearing novel biaryl indazoles as P2/P2' substituents was undertaken, utilizing a Suzuki coupling reaction as the key step. Compound 6i was equipotent to the lead compound of the series SE063.

Two series of benzoxazinones differing in the aromatic substitution pattern were prepared and evaluated as HIV-1 reverse transcriptase inhibitors. The 5-fluoro (5a-d) and 6-nitro (5e-h) substituted compounds displayed activity comparable or better than Efavirenz, the lead structure of the series.

An efficient method for the expression and purification of nucleocapsid precursor protein (p15NC) from HIV-I (BH 10 isolate) was developed and used to obtain large quantities of this viral protein for structural studies, protein biochemistry, and high-throughput screening efforts. We have engineered an existing p15NC clone into a new vector developed at the University of Heidelberg, Germany. Using PCR, we introduced new restriction sites and a strong ribosome-binding site in the p15NC gene and expressed authentic p15NC protein. Our protocol enabled us to rapidly obtain soluble and highly stable p15NC expressed in Escherichia coli and to purify several milligrams of p15NC to homogeneity. In the current purification scheme, lysis of cell paste followed by a simple three-step FPLC procedure yields about 0.4-0.5 mg of purified p15NC per gram of E. coli cell paste expressing the protein with an overall yield of 45%. The purified p15NC retained its ability to bind full-length HIV-I p15NC mRNA in solution- or solid-phase-based assays. A specific stem-loop forming RNA fragment (24-mer) and its antisense DNA oligomer (21-mer) derived from the full-length p15NC mRNA were also able to bind to p15NC. In addition, antisense DNA oligos with bulky 5-iodouracil and 5-iodocytidine substituents were able to bind to p15NC with little or no perturbations as assessed by their ability to compete with the full-length p15NC mRNA in filter-binding competition assays. In addition, RNA-dependent cleavage of the purified p15NC in vitro by HIV-I protease occurred at rates similar to those reported previously.

Two series of cyclic ureas modified at the P1/P1′ residue were prepared and evaluated for HIV protease inhibition and whole cell antiviral activity. Compounds 8b, 10 (3- and 4-pyridylmethyl analogs) and 6b (4-methoxy analog) showed significant improvement in antiviral activity relative to lead compounds DMP323 and DMP 450.

Comparison of the high-resolution X-ray structures of the native HIV-1 protease and its complexes with the inhibitors suggested that the enzyme flaps are flexible. The movement at the tip of the flaps could be as large as 7 A. On the basis of this observation, cyclic cyanoguanidines have been designed, synthesized, and evaluated as HIV-1 protease (PR) inhibitors. Cyclic cyanoguanidines were found to be very potent inhibitors of HIV-1 protease. The choice of cyclic cyanoguanidines over cyclic guanidines was based on the reduced basicity of the former. X-ray structure studies of the HIV PR complex with cyclic cyanoguanidine demonstrated that in analogy to cyclic urea, cyclic cyanoguanidines also displace the unique structural water molecule. The structure-activity relationship of the cyclic cyanoguanidines is compared with that of the corresponding cyclic urea analogues. The differences in binding constants of the two series of compounds have been rationalized using high-resolution X-ray structure information.

Cyclic ureas containing 3-aminoindazole P2/P2′ groups are extremely potent inhibitors of HIV protease. The parent 3-aminoindazole 6 showed a K i × 0.01 nM but poor translation of enzyme activity to antiviral activity was observed. A series of 3-alkylaminoindazoles revealed that translation improved with increasing lipophilicity. An X-ray crystal structure of 6 bound to HIV protease was obtained.

During human immunodeficiency virus type 1 (HIV-1) virion assembly, cleavage of the Gag precursor by the viral protease results in the transient appearance of a nucleocapsid-p1-p6 intermediate product designated p15NC. Utilizing the p15NC precursor protein produced with an in vitro transcription-translation system or purified after expression in Escherichia coli, we have demonstrated that RNA is required for efficient cleavage of HIV p15NC. Gel mobility shift and nitrocellulose filter binding experiments indicate that purified p15NC protein specifically binds its corresponding mRNA with an estimated Kd of 1.5 nM. Binding was not affected by the presence or absence of zinc or EDTA. Moreover, mutagenesis of the cysteine residues within either of the two Cys-His arrays had no effect on RNA binding or on RNA-dependent cleavage by the viral protease. In contrast, decreased binding of RNA and diminished susceptibility to cleavage in vitro were observed with p15NC-containing mutations in one or more residues within the triplet of basic amino acids present in the region between the two zinc fingers. In addition, we found that 21- to 24-base DNA and RNA oligonucleotides of a particular sequence and secondary structure could substitute for p15 RNA in the enhancement of p15NC cleavage. Virus particles carrying a mutation in the triplet of NC basic residues (P3BE) show delayed cleavage of p15NC and a defect in core formation despite the eventual appearance of fully processed virion protein. These results define determinants of the p15NC-RNA interaction that lead to enhanced protease-mediated cleavage and demonstrate the importance of the triplet of basic residues in formation of the virus core.

A series of analogs of HIV protease inhibitor DMP323 containing functionalized aliphatic P2/P2′ groups was prepared and evaluated for HIV protease inhibition and antiviral activity in a cell-based assay. Asymmetric compounds with a 5-hydroxypentyl substituent at P2 and a benzylic substituent at P2′ showed increased potency over the corresponding symmetrically substituted analogs.

A new era has begun in the chemotherapeutic treatment of AIDS with the marketing of the first generation of peptidomimetic HIV protease inhibitors from Roche, Merck and Abbott. Owing to the potential drug resistance problems associated with HIV mutations, a main emphasis in the search for the next generation of HIVPR drugs is in the area of structurally different cyclic nonpeptides. This article reviews the different approaches that have been undertaken to find or design cyclic nonpeptides that are capable of displacing the structural water molecule usually associated with the peptidomimetic class of inhibitors. The favorable entropic effect from water displacement and preorganization can lead to smaller and more potent inhibitors with improved therapeutic potential.

Background Ruxolitinib, a Janus kinase 1 and 2 inhibitor, demonstrated improvements in spleen volume, symptoms, and survival over placebo and best available therapy in intermediate-2 or high-risk myelofibrosis patients with baseline platelet counts ≥100 × 109/L in phase III studies. The most common adverse events were dose-dependent anemia and thrombocytopenia, which were anticipated because thrombopoietin and erythropoietin signal through JAK2. These events were manageable, rarely leading to treatment discontinuation. Because approximately one-quarter of MF patients have platelet counts

A series of benzofused heterocycles was examined to replace the metabolically unstable benzyl alcohol P2/P2′ groups of DMP 323 (1). Extremely potent inhibitors of HIV protease (Ki

Several bis- N -alkylated (+)-biotin derivatives were synthesized and evaluated for activities against HIV-1 protease. The most potent inhibitor, 2D , synthesized in two steps from (+)-biotin, has K i of 0.50 μM and antiviral IC 90 of 7 μM. The (+)-biotin analogs in general have good translations from enzymatic K i to antiviral cell assay IC 90 .

Synthetic efforts to overcome the metabolic oxidative degradation of the HIV protease inhibitory cyclic urea DMP323 , a benzyl alcohol, have led to the discovery of a tertiary carbinol with superior affinity for the viral protease and more potent inhibitory activity against viral replication. Synthetic approaches to this new carbinol and comparative analysis of its pharmacology and pharmacokinetics are presented.

A B S T R AC T background Ruxolitinib, a selective inhibitor of Janus kinase (JAK) 1 and 2, has clinically significant activity in myelofibrosis. methodS In this double-blind trial, we randomly assigned patients with intermediate-2 or highrisk myelofibrosis to twice-daily oral ruxolitinib (155 patients) or placebo (154 patients). The primary end point was the proportion of patients with a reduction in spleen volume of 35% or more at 24 weeks, assessed by means of magnetic resonance imaging. Secondary end points included the durability of response, changes in symptom burden (assessed by the total symptom score), and overall survival. resulTS The primary end point was reached in 41.9% of patients in the ruxolitinib group as compared with 0.7% in the placebo group (P

Low-molecular-weight peptidyl aldehyde inhibitors of HIV protease that reach in vivo plasma concentrations after oral administration substantiailly in excess of the antiviral IC90 are described. We also report efforts to improve the potency and stability of these compounds that culminated in a series of peptidyl trifluoromethyl ketones with increased potency but decreased bioavailability.

DMP 323 is a potent inhibitor of the protease of human immunodeficiency virus (HIV), with antiviral activity against both HIV type 1 and HIV type 2. This compound is representative of a class of small, novel, nonpeptide cyclic urea inhibitors of HIV protease that were designed on the basis of three-dimensional structural information and three-dimensional database searching. We report here studies of the kinetics of DMP 323 inhibition of the cleavage of peptide and HIV-1 gag polyprotein substrates. DMP 323 acts as a rapidly binding, competitive inhibitor of HIV protease. DMP 323 is as potent against both peptide and viral polyprotein substrates as A-80987, Q8024, and Ro-31-8959, which are among the most potent inhibitors of HIV protease described in the literature to date. Incubation with human plasma or serum did not decrease the effective potency of DMP 323 for HIV protease, suggesting that plasma protein binding is of a low affinity relative to that of HIV protease. DMP 323 was also assessed for its ability to inhibit the mammalian proteases renin, pepsin, cathepsin D, cathepsin G, and chymotrypsin. No inhibition of greater than 12% was observed for any of these enzymes at concentrations of DMP 323 that were 350 to 40,000 times higher than that required to inhibit the viral protease 50%.

Mechanistic information and structure-based design methods have been used to design a series of nonpeptide cyclic ureas that are potent inhibitors of human immunodeficiency virus (HIV) protease and HIV replication. A fundamental feature of these inhibitors is the cyclic urea carbonyl oxygen that mimics the hydrogen-bonding features of a key structural water molecule. The success of the design in both displacing and mimicking the structural water molecule was confirmed by x-ray crystallographic studies. Highly selective, preorganized inhibitors with relatively low molecular weight and high oral bioavailability were synthesized.

C-C chemokine receptor 5 (CCR5) is a clinically proven target for inhibition of HIV-1 infection and a potential target for various inflammatory diseases. In this article, we describe 5-[(4-{(3S)-4-[(1R,2R)-2-ethoxy-5-(trifluoromethyl)-2,3-dihydro-1H-inden-1-yl]-3-methylpiperazin-1-yl}-4-methylpiperidin-1-yl)carbonyl]-4,6-dimethylpyrimidine dihydrochloride (INCB9471), a potent and specific inhibitor of human CCR5 that has been proven to be safe and efficacious in viral load reduction in phase I and II human clinical trails. INCB9471 was identified using a primary human monocyte-based radioligand competition binding assay. It potently inhibited macrophage inflammatory protein-1β-induced monocyte migration and infection of peripheral blood mononuclear cells by a panel of R5-HIV-1 strains. The results from binding and signaling studies using incremental amounts of INCB9471 demonstrated INCB9471 as a noncompetitive CCR5 inhibitor. The CCR5 residues that are essential for interaction with INCB9471 were identified by site-specific mutagenesis studies. INCB9471 rapidly associates with but slowly dissociates from CCR5. When INCB9471 was compared with three CCR5 antagonists that had been tested in clinical trials, the potency of INCB9471 in blocking CCR5 ligand binding was similar to those of 4,6-dimethyl-5-{[4-methyl-4-((3S)-3-methyl-4-{(1R0-2-(methyloxy)-1-[4-(trifluoromethyl) phenyl]ethyl}-1-piperazingyl)-1-piperidinyl]carbonyl}pyrimidine (SCH-D; vicriviroc), 4-{[4-({(3R)-1-butyl-3-[(R)-cyclohexyl(hydroxyl)methyl]-2, 5-dioxo-1,4,9-triazaspiro[5.5]undec-9-yl}methyl)phenyl]oxy}benzoic acid hydrochloride (873140; aplaviroc), and 4,4-difluoro-N-((1S)-3-{(3-endo)-3-[3-methyl-5-(1-methylethyl)-4H-1,2,4-triazol-4-yl]-8-azabicyclo[3.2.1]oct-8-yl}-1-phenylpropyl)cyclohexanecarboxamide (UK427857; maraviroc). Its inhibitory activity against CCR5-mediated Ca(2+) mobilization was also similar to those of SCH-D and 873140. Further analysis suggested that INCB9471 and UK427857 may have different binding sites on CCR5. The significance of two CCR5 antagonists with different binding sites is discussed in the context of potentially overcoming drug-resistant HIV-1 strains.

A series of 4,4-disubstituted quinolinones was prepared and evaluated as HIV-1 reverse transcriptase inhibitors. The C-3 substituted compound 9h displayed improved antiviral activity against clinically significant single (K103N) and double (K103N/L100I) mutant viruses.

Synthetic efforts to overcome the metabolic oxidative degradation of the HIV protease inhibitory cyclic urea DMP323 , a benzyl alcohol, have led to the discovery of a tertiary carbinol with superior affinity for the viral protease and more potent inhibitory activity against viral replication. Synthetic approaches to this new carbinol and comparative analysis of its pharmacology and pharmacokinetics are presented.

Several bis- N -alkylated (+)-biotin derivatives were synthesized and evaluated for activities against HIV-1 protease. The most potent inhibitor, 2D , synthesized in two steps from (+)-biotin, has K i of 0.50 μM and antiviral IC 90 of 7 μM. The (+)-biotin analogs in general have good translations from enzymatic K i to antiviral cell assay IC 90 .

A series of benzofused heterocycles was examined to replace the metabolically unstable benzyl alcohol P2/P2′ groups of DMP 323 (1). Extremely potent inhibitors of HIV protease (Ki

Two series of cyclic ureas modified at the P1/P1′ residue were prepared and evaluated for HIV protease inhibition and whole cell antiviral activity. Compounds 8b, 10 (3- and 4-pyridylmethyl analogs) and 6b (4-methoxy analog) showed significant improvement in antiviral activity relative to lead compounds DMP323 and DMP 450.

Benzothiadiazine non-nucleoside reverse transcriptase inhibitors (NNRTIs) of HIV have been synthesized via a novel process to afford active inhibitors, with the most potent compound exhibiting an IC90=180 nM in a whole cell assay. The 2,2-dioxide-1H-2,1,3-benzothiadiazine ring system was constructed in one step from 2-amino-5-chlorobenzonitrile.

Two series of efavirenz analogues have been developed: one in which the cyclopropane ring has been replaced by small heterocycles and another in which the entire acetylenic side chain has been replaced by alkyloxy groups. Several members of both series show equivalent potency to efavirenz against both wild-type virus and the key K103N mutant.

A series of 4,4-disubstituted quinolinones was prepared and evaluated as HIV-1 reverse transcriptase inhibitors. The C-3 substituted compound 9h displayed improved antiviral activity against clinically significant single (K103N) and double (K103N/L100I) mutant viruses.

CD and fluorescence spectroscopic measurements show that calmodulin (CaM) binds to purothionins (alpha 1-purothionin: alpha 1-PT; beta-purothionin: beta-PT) in 1:1 stoichiometry with an affinity similar to that exhibited with the tightest binding CaM-binding peptides. Using the available crystal structures of CaM and alpha 1-PT, a model has been built for the interaction of CaM and alpha 1-PT and subjected to potential energy minimization. In the model, there is a bend in the central helix of CaM similar to that suggested by Persechini and Kretsinger (J. Card. Pharm. 12:501-512, 1988). alpha 1-PT fits snugly into the cavity formed by the bent CaM molecule with each of its two helices making apolar interactions with each of the two hydrophobic clefts situated at the terminal domains of CaM. The complex is further stabilized by numerous polar and electrostatic interactions on the rims of the clefts. Our model is compared with two other similar models previously reported for the CaM complexes with other helical peptides and generalizations about the mode of CaM binding to target proteins are made, which have wide relevance to the function of CaM. By analogy, a similar model is predicted for a CaM-beta-PT complex.