Antiviral Therapy 2015; 20: (doi: /IMP2920)

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1 Antivirl Therpy 2015; 20: (doi: /IMP2920) Originl rticle Sfety, tolerbility nd phrmcokinetics of dorvirine, novel HIV non-nucleoside reverse trnscriptse inhibitor, fter single nd multiple doses in helthy subjects Mtt S Anderson 1 *, Jocelyn Gilmrtin 1, Croline Cilissen 2, Inge De Lepeleire 2, Luc Vn Bortel 3, Mriss F Dockendorf 1, Ernestin Tetteh 1, June K Ancon 1, Rchel Liu 1, Ying Guo 1, John A Wgner 1, Jon R Butterton 1 1 Merck & Co., Inc., Kenilworth, NJ, USA 2 Merck, Shrp & Dohme (Europe) Inc., Brussels, Belgium 3 University Hospitl Ghent, Drug Reserch Unit, Ghent, Belgium *Corresponding uthor e-mil: mtt_nderson@merck.com Bckground: Dorvirine is novel non-nucleoside inhibitor of HIV-1 reverse trnscriptse with potent ctivity ginst wild-type virus (95% inhibitory concentrtion 19 nm, 50% humn serum). Dorvirine hs low potentil to cuse drug drug interctions since it is primrily eliminted by oxidtive metbolism nd does not inhibit or significntly induce drug-metbolizing enzymes. Methods: The phrmcokinetics nd sfety of dorvirine were investigted in two double-blind, dose-escltion studies in helthy mles. Thirty-two subjects received single doses of dorvirine (6 1,200 mg) or mtching plcebo tblets; 40 subjects received dorvirine ( mg) or mtching plcebo tblets once dily for 10 dys. In ddition, the effect of dorvirine (120 mg for 14 dys) on single-dose phrmcokinetics of the CYP3A substrte midzolm ws evluted (10 subjects). Results: The mximum plsm concentrtion (C mx ) of dorvirine ws chieved within 1 5 h with n pprent terminl hlf-life of h. Consistent with single-dose phrmcokinetics, stedy stte ws chieved fter pproximtely 7 dys of once dily dministrtion, with ccumultion rtios (dy 10/dy 1) of in the re under the plsm concentrtion time curve during the dosing intervl (AUC 0 24 h ), C mx nd trough plsm concentrtion (C 24 h ). All dose levels produced C 24 h >19 nm. Administrtion of 50 mg dorvirine with high-ft mel ws ssocited with slight elevtions in AUC time zero to infinity (AUC 0 ) nd C 24 h with no chnge in C mx. Midzolm AUC 0 ws slightly reduced by codministrtion of dorvirine (geometric men rtio 0.82, 90% CI 0.70, 0.97). There ws no pprent reltionship between dverse event frequency or intensity nd dorvirine dose. No rsh or significnt centrl nervous system events other thn hedche were reported. Conclusions: Dorvirine is generlly well tolerted in single doses up to 1,200 mg nd multiple doses up to 750 mg once dily for up to 10 dys, with phrmcokinetic profile supportive of once-dily dosing. Dorvirine t stedy stte slightly reduced the exposure of codministered midzolm, to cliniclly unimportnt extent. Introduction Dorvirine (lso known s MK-1439) is n llosteric inhibitor of HIV-1 reverse trnscriptse (RT) tht binds to hydrophobic pocket in the p66 subunit of the p66/ p51 heterodimer ner the polymerse ctive site, the clssic binding pocket for non-nucleoside RT inhibitors (NNRTIs). Five NNRTIs re currently vilble for clinicl use: efvirenz, nevirpine, delvirdine, etrvirine nd rilpivirine. However, the genetic brrier to resistnce development in this clss is reltively low, nd virl strins resistnt to current NNRTIs cn limit their clinicl utility [1]. In biochemicl ssys, dorvirine displys 95% inhibitory concentrtion (IC 95 )of 19 nm in the inhibition of the RNA-dependent DNA polymeriztion ctlysed by HIV-1 RT nd lso displys low nnomolr potencies versus the most prevlent NNRTI resistnt mutnts (for exmple, mutnt viruses K103N: IC nm; Y181C: IC nm; K103N/Y181C: IC nm). Dorvirine exhibits superior resistnce profile 2015 Interntionl Medicl Press (print) (online) 397

2 MS Anderson et l. compred with the most widely used NNRTI, efvirenz, when tested ginst broder rry of cliniclly relevnt NNRTI-resistnt viruses in ntivirl ssys [2]. In ddition, non-b subtype viruses re lso highly susceptible to dorvirine with 50% effective concentrtion (EC 50 ) similr to tht obtined with B subtype viruses. Dorvirine displys moderte (pproximtely 75%) binding to humn plsm proteins. In vitro nd clinicl studies hve demonstrted tht dorvirine is primrily clered by CYP3A4 metbolism with smll component (pproximtely 6% of dministered dose) of elimintion vi renl excretion. Dorvirine hs low potentil to cuse drug interctions; it is not n inhibitor of mjor CYP enzymes (CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 nd 3A4) nd hs miniml potentil to induce CYP3A4 ctivity. In vitro evlution indicted tht dorvirine is substrte of humn P-glycoprotein but not of OATP1B1. Cliniclly significnt drug interctions vi inhibition of mjor humn efflux nd uptke trnsporters re not nticipted bsed on in vitro dt. This report describes the results of two Phse I studies conducted in helthy subjects to investigte the single- nd multiple-dose phrmcokinetics nd sfety of dorvirine. The effect of food on the single-dose phrmcokinetics of dorvirine, nd the influence of stedystte dorvirine on the single-dose phrmcokinetics of the CYP3A substrte midzolm, were lso evluted. Methods Study 1 (MK-1439 Protocol 001; EudrCT ) ws double-blind, rndomized, plcebocontrolled study in helthy mle subjects between 18 nd 50 yers of ge (inclusive) conducted from 17 Mrch 2011 to 30 August Prt I explored rising single doses of dorvirine rnging from 6 to 450 mg in two lternting pnels of eight subjects ech (Tble 1). Subjects were rndomly ssigned to receive dorvirine (n=6) or mtching plcebo (n=2) in up to five tretment periods, with 7 14 dys wshout between periods. All doses were dministered fter fsting, with the exception of 50 mg, which ws given fter fsting in one period nd fter high-ft brekfst (500 clories in ft, 220 clories in crbohydrtes nd 24 clories in protein) in nother period to evlute the effect of food. Prt II ws n explortion of multiple doses of dorvirine in four seril, rising multiple-dose pnels (Tble 2). Subjects were rndomly ssigned to receive dorvirine (n=6) 30, 60 or 240 mg, respectively, or mtching plcebo (n=2) once dily for 10 dys. To evlute the effect of dorvirine dministrtion on CYP3A4 ctivity, ten subjects received dorvirine 120 mg (n=8) or mtching plcebo (n=2) once dily for 14 dys, plus single 2-mg dose of midzolm HCl syrup (2 mg/ml) on dys -1 nd 13. Study 2 (MK-1439 Protocol 006; EudrCT ) ws double-blind, rndomized, plcebocontrolled study in helthy mle subjects between 18 nd 50 yers of ge conducted from 8 November 2011 to 1 June 2012, to evlute higher doses of dorvirine thn those explored in study 1. Two pnels of eight subjects ech were rndomly ssigned to receive dorvirine or mtching plcebo (in 3:1 rtio) in up to three tretment periods (Tble 3). In periods 1 nd 2, subjects received single orl dose of dorvirine (600 to 1,200 mg) or mtching plcebo, respectively. In period 3, subjects received dorvirine (450 or 750 mg) or mtching plcebo once dily for 10 dys. Ech subject hd 7-dy wshout period between study drug dministrtion in period 1 nd 2, nd between period 2 nd the first dose of study drug in period 3. Both studies were conducted t University Hospitl Ghent, Drug Reserch Unit, Ghent, Belgium nd followed pplicble country or locl requirements regrding ethicl committee review, informed consent, nd other sttutes or regultions regrding the protection of the rights nd welfre of humn subjects prticipting in biomedicl reserch. The study protocols were pproved by the Ethicl Review Committee of Tble 1. Dorvirine rising single-dose tretment groups (study 1, prt I) Pnel Period 1 Period 2 Period 3 Period 4 Period 5 A 6 mg 25 mg 100 mg 300 mg 450 mg B 12 mg 50 mg 150 mg 50 mg with food 600 mg Eight subjects per pnel. In ech period, six subjects received dorvirine nd two received mtching plcebo. The 600 mg dose (pnel B, period 5) ws not dministered. Tble 2. Dorvirine rising multiple-dose tretment groups (study 1, prt II) Pnel C D E b F Dose ssignment 30 mg once dily 10 dys 60 mg once dily 10 dys 120 mg once dily 14 dys (dys 1 14) nd 2.0 mg midzolm HCL syrup s single doses on dys -1 nd mg once dily 10 dys Eight subjects received dorvirine (n=6) or mtching plcebo (n=2). b Ten subjects received dorvirine (n=8) or mtching plcebo (n=2). Tble 3. Dorvirine higher dose tretment groups (study 2) Pnel Period 1 Period 2 Period 3 A 600 mg 800 mg 500 mg once dily 10 dys B 1,000 mg 1,200 mg 750 mg once dily 10 dys Eight subjects per pnel. In ech period, six subjects received dorvirine nd two received mtching plcebo Interntionl Medicl Press

3 Sfety, tolerbility nd phrmcokinetics of dorvirine in helthy subjects University Hospitl Ghent, nd ll subjects provided written informed consent before ny study procedures were performed. To be eligible for the study, subjects were to be non-smokers in good helth bsed on medicl history, physicl exmintion, vitl sign mesurements nd lbortory sfety tests, with body mss index 35 kg/m 2, estimted cretinine clernce >80 ml/min nd no cliniclly significnt bnormlities on electrocrdiogrm (ECG). The use of ny mediction (other thn cetminophen) from pproximtely 2 weeks (or 5 hlf-lives) before the initil dose of study drug until the post-study visit required pprovl of the investigtor nd the sponsor. Study drugs were provided s tblets t potencies of 1 mg, 10 mg nd 100 mg of dorvirine or plcebo for ll study pnels. Blood smples were obtined t multiple time points to ssess dorvirine single-dose nd multiple-dose phrmcokinetics nd to determine the phrmcokinetic prmeters of midzolm before nd fter multiple doses of dorvirine. Sfety ws ssessed by repeted clinicl evlution of dverse events nd inspection of other study prmeters including vitl signs, medicl history, physicl exmintion, 12-led ECG nd stndrd lbortory sfety tests (hemtology, chemistry nd urinlysis). Anlyticl nd phrmcokinetic methods Plsm smples were nlysed for dorvirine concentrtion using vlidted liquid chromtogrphy-tndem mss spectrometry (LC-MS/MS) ssy with lower limit of quntittion of 2.3 nm. Plsm smples were nlysed by inventiv Helth Clinique (Quebec City, QC, Cnd) for midzolm concentrtions using liquid liquid extrction nd vlidted LC-MS/MS ssy (lower limit of detection 20 pg/ml; clibrtion rnge 20 to 20,000 pg/ml). The mximum plsm concentrtion (C mx ), time to mximum plsm concentrtion (T mx ) nd trough plsm concentrtion (C 24 h ) were obtined directly from plsm concentrtion time dt. The re under the plsm concentrtion time curve (AUC) from time zero to infinity (AUC 0 ) nd during the dosing intervl (AUC 0 24 h ) were clculted using the liner up/log down trpezoidl method. The pprent terminl hlf-life ws clculted s (ln2)/l, where l is the pprent terminl rte constnt, clculted from semi-log plot of the plsm concentrtion-versus-time curve. Time to stedy stte ws determined by visul inspection. Sttisticl nlysis Anlysis of the single-dose dt used liner mixedeffects model with fixed effect for tretment nd rndom effect for subject. Anlysis of the multiple-dose dt used liner mixed-effects model with dose, dy (dy 1 nd the lst dy of dosing) nd dose-by-dy interction s fixed effects, nd subject-within-dose s rndom effect. Nturl log trnsformtion ws performed for C 24 h, C mx, AUC 0 nd AUC 0 24 h before nlysis. Results Subjects Fifty mle subjects (46 White, 3 Blck, 1 Asin) between 20 nd 49 yers of ge (men 30.0 yers) enrolled in study 1; weight rnged from 63.0 to kg (men 79.5 kg). None of the subjects required concomitnt mediction during the study. Forty-eight subjects completed the study. One subject (ssigned to dorvirine 120 mg once dily) discontinued due to lbortory dverse event (detils provided in Sfety) nd one (ssigned to plcebo) discontinued from the study for personl resons. Sixteen mle subjects (ll white) between 23 nd 50 yers of ge (men, 38.4 yers) enrolled in study 2; weight rnged from 67.4 to kg (men 85.5 kg). Concomitnt medictions used during the study were cetminophen for one dy in three subjects, nd cetminophen nd ibuprofen for one dy nd moxicillin/ clvulnic cid for 6 dys in one subject. Fifteen subjects completed the study. One subject (ssigned to dorvirine 750 mg once dily) discontinued due to serious dverse event (detils provided in Sfety). Phrmcokinetics Single doses of dorvirine given in the fsted stte were rpidly bsorbed, with medin T mx vlues rnging from 1.0 to 4.0 h post-dose (Tble 4). Dorvirine plsm concentrtions declined in single exponentil phse (Figure 1), with n pprent terminl hlf-life of 12 to 19 h. Dorvirine AUC 0, AUC 0 24 h, C mx nd C 24 h vlues incresed in slightly less thn dose-proportionl mnner (Tble 4). When dorvirine 50 mg ws dministered with high-ft mel, the medin T mx ws 5.0 h, AUC 0 nd C 24 h incresed slightly (fed/fsted geometric men rtios [GMRs] nd 90% CIs: 1.33 [1.12, 1.57] nd 1.56 [1.28, 1.91], respectively), nd C mx remined unchnged (GMR [90% CI]: 0.95 [0.78, 1.16]). Over 24-h period, 6.29% of single 50-mg dose (in the fsted stte) ws excreted unchnged in the urine nd the men observed renl clernce ws 9.43 ml/min. Consistent with single-dose results, multiple-dose dt indicte tht dorvirine is rpidly bsorbed (Tbles 5 nd 6). The medin T mx vlues on dys 1 nd 10 (or 1 nd 14 for the 120-mg dose) rnged from 1.0 to 4.0 h. After dys of once-dily dosing, dorvirine plsm concentrtions declined in single exponentil phse (Figure 2), with n pprent terminl hlf-life of 13 to 21 h. Most subjects chieved stedy stte by dy 7. Stedy stte AUC 0 24 h nd C mx incresed in slightly less thn dose-proportionl mnner, s ws observed during single-dose dministrtion. At stedy Antivirl Therpy

4 MS Anderson et l. Tble 4. Summry sttistics of phrmcokinetic prmeters of dorvirine fter single orl doses in helthy mles Apprent Dose, mg AUC 0, µm h AUC 0 24 h, µm h C mx, nm C 24 h, nm T mx, h b terminl t 1/2, h c Study (1.00, 4.00) (10.0) (2.36, 3.51) (1.71, 2.40) (126.79, ) (35.26, 54.79) (1.00, 3.00) (15.7) (3.94, 5.86) (3.05, 4.29) (239.13, ) (57.30, 89.23) (1.00, 6.00) (20.4) (9.20, 13.66) (5.92, 8.32) (374.33, ) (155.25, ) , (1.00, 4.00) (10.6) (14.47, 21.56) (10.68, 15.04) (864.84, 1,317.27) (215.63, ) 50 d , (3.00, 6.00) (12.0) (19.23, 28.67) (13.39, 18.84) (824.40, 1,255.67) (337.37, ) , (1.00, 5.00) (44.0) (31.46, 46.66) (19.28, 27.06) (1,391.54, 2,109.15) (476.08, ) , (1.00, 4.00) (27.6) (41.14, 61.15) (28.76, 40.41) (2,153.30, 3,270.44) (608.14, ) , , (2.00, 5.00) (27.1) (75.92, ) (49.66, 69.78) (3,101.00, 4,708.85) (1,194.25, 1,859.21) , , (1.00, 5.00) (34.5) (103.93, ) (69.56, 97.62) (4,883.42, 7,401.78) (1,659.77, 2,578.84) Study , , (0.50, 4.00) (14.1) (121.66, ) (86.49, ) (6,175.06, 8,907.35) (1,833.50, 2,746.23) , , (2.00, 5.00) (27.0) (149.68, ) (101.09, ) (6,810.20, 9,823.53) (2,102.36, 3,148.93) 1, , , (0.50, 5.00) (11.0) (180.42, ) (118.04, ) (8,397.47, 12,113.12) (2,614.42, 3,915.89) 1, , , (1.00, 5.00) (34.2) (205.65, ) (130.60, ) (8,982.78, 12,957.41) (2,970.73, 4,449.58) Bck-trnsformed lest-squres men nd 95% CI from liner mixed-effects model performed on nturl log-trnsformed vlues. b Medin (min, mx). c Geometric men (geometric men percent coefficient of vrition). d After high-ft mel; other doses were given in the fsted stte. AUC 0, re under the plsm concentrtion time curve from time zero to infinity; AUC 0 24 h, re under the plsm concentrtion time curve during the dosing intervl; C mx, mximum plsm concentrtion; C 24 h, trough plsm concentrtion; T mx, time to mximum plsm concentrtion; t 1/2, hlf-life. stte, the men AUC 0 24 h, C mx nd C 24 h ccumultion rtios, expressed s the dy 10/dy 1 GMRs (or dy 14/ dy 1 GMRs for the 120-mg dose) were 1.1 to 1.5, consistent with predictions from single-dose dt. However, some vribility in individul ccumultion rtios ws noted. The observed AUC 0 24 h ccumultion rtios t ech dose correspond to men effective ccumultion hlf-life of pproximtely 9 to 14 h. The overll shpe of the single-dose midzolm concentrtion time profile ws similr whether dministered lone or with dorvirine 120 mg t stedy stte (Additionl file 1). Midzolm exposure (AUC 0 ) ws slightly decresed in the presence of dorvirine (GMR [90% CI] 0.82 [0.70, 0.97]), while C mx ws unchnged (GMR [90% CI] 1.02 [0.81, 1.28]; Tble 7). Sfety Study 1: 34 subjects reported totl of 98 non-serious clinicl dverse events. Of the 37 dverse events considered possibly or probbly relted to study drug, 26 occurred in subjects who received dorvirine: hedche (12), bck pin (2), dizziness (2), somnolence (2), bdominl discomfort (1) or pin (1), dysgeusi (1), ftigue (1), feeling hot (1), involuntry leg muscle contrctions (1), loose stools (1) nd neck stiffness (1). Dorvirine (120 mg once dily) ws discontinued in one subject due to slightly elevted sprtte trnsminse (AST; 1.6 upper limit of norml [ULN]) with norml lnine minotrnsferse (ALT; 0.71 ULN) nd very high cretine kinse (CK; 15.0 ULN) on dy 5. These vlues peked on dy 7 (AST 2.8 ULN, ALT 1.1 ULN, CK 30.4 ULN) nd declined to within norml rnge over the next 7 dys. The subject did not report ny clinicl symptoms t ny time during this period. This event ws judged to be relted to muscle dmge due to ptient-reported hevy physicl ctivity, possibly ggrvted by the concomitnt use of dorvirine. A second subject, who received plcebo to mtch 30 mg dorvirine, withdrew consent for personl resons following the dy 4 dose Interntionl Medicl Press

5 Sfety, tolerbility nd phrmcokinetics of dorvirine in helthy subjects Figure 1. Men dorvirine plsm concentrtion versus time profile following single doses of dorvirine, 6 to 1,200 mg, in helthy mle subjects 100,000 10,000 12,000 1,000 Men dorvirine plsm concentrtion, nm 10,000 8,000 6,000 4,000 2, mg 12 mg 25 mg 50 mg 100 mg 150 mg 50 mg with food 300 mg 450 mg 600 mg 800 mg 1,000 mg 1,200 mg Liner scle, first 72 h post-dose. Inset: semi-log scle. Tble 5. Summry sttistics of phrmcokinetic prmeters of dorvirine fter once-dily orl doses in fsted helthy mles (study 1) Apprent Dose, mg Dy n AUC 0 24 h, µm h C mx, nm C 24 h, nm T mx, h b terminl t 1/2, h c (6.49, 10.92) (515.32, ) (125.16, ) 1.00 (1.00, 5.00) NA (8.84, 14.87) (610.63, 1,036.93) (173.73, ) 3.50 (1.00, 5.00) (11.3) GMR d 10/ (1.19, 1.56) 1.18 (0.99, 1.42) 1.39 (1.17, 1.64) (10.87, 18.28) 1, (785.50, 1,333.89) (237.22, ) 3.00 (1.00, 4.02) NA (13.36, 22.48) 1, (1,000.07, 1,698.26) (271.97, ) 2.00 (1.00, 4.00) (18.3) GMR d 10/ (1.07, 1.41) 1.27 (1.07, 1.52) 1.15 (0.97, 1.36) (21.81, 34.21) 1, (1,527.08, 2,415.61) (496.92, ) 2.00 (1.00, 4.00) NA 14 7 e (29.22, 46.32) 2, (1,985.69, 3,192.88) (644.19, 1,187.73) 4.00 (1.00, 5.00) (22.9) GMR d 14/ (1.19, 1.53) 1.31 (1.11, 1.54) 1.30 (1.12, 1.52) (33.73, 56.75) 3, (2,488.80, 4,226.35) 1, (751.13, 1,502.54) 1.50 (1.00, 5.00) NA (46.72, 78.58) 4, (3,433.81, 5,831.12) 1, (947.90, 1,896.14) 3.00 (1.00, 5.00) (15.9) GMR d 10/ (1.21, 1.59) 1.38 (1.16, 1.65) 1.26 (1.07, 1.49) Bck-trnsformed lest-squres men nd 95% CI from liner mixed-effects model performed on nturl log-trnsformed vlues. b Medin (min, mx). c Geometric men (geometric men percent coefficient of vrition). d Dy 10 or 14/dy1: bck-trnsformed geometric men rtio (GMR) nd 90% CI from liner mixed-effects model performed on nturl log-trnsformed vlues. e One subject ws excluded due to insufficient phrmcokinetic smpling. AUC 0 24 h, re under the plsm concentrtion time curve during the dosing intervl; C mx, mximum plsm concentrtion; C 24 h, trough plsm concentrtion; NA, not pplicble; T mx, time to mximum plsm concentrtion; t 1/2, hlf-life. Antivirl Therpy

6 MS Anderson et l. Tble 6. Summry sttistics of phrmcokinetic prmeters of dorvirine fter once-dily orl doses in fsted helthy mles (study 2) Apprent Dose, mg Dy n AUC 0 24 h, µm h C mx, nm C 24 h, nm T mx, h b terminl t 1/2, h c (70.21, 95.72) 5, (4,814.61, 6,463.55) 1, (1,516.41, 2,472.71) 3.00 (1.00, 4.00) NA (85.74, ) 7, (6,550.50, 8,793.95) 2, (1,638.40, 2,671.64) 1.50 (1.00, 4.00) (30.5) GMR d 10/ (1.13, 1.32) 1.36 (1.15, 1.61) 1.08 (0.95, 1.23) (84.92, ) 6, (6,020.88, 8,082.94) 2, (1,854.27, 3,023.66) 3.00 (1.00, 5.00) NA 10 5 e (117.59, ) 10, (8,909.63, 12,370.41) 2, (2,219.84, 3,670.79) 1.00 (0.52, 5.00) (55.1) GMR d 10/1 5 e 1.39 (1.28, 1.51) 1.50 (1.26, 1.79) 1.21 (1.04, 1.39) Bck-trnsformed lest-squres men nd 95% CI from liner mixed-effects model performed on nturl log-trnsformed vlues. b Medin (min, mx). c Geometric men (geometric men percent coefficient of vrition). d Dy 10/dy1: bck-trnsformed geometric men rtio (GMR) nd 90% CI from liner mixed-effects model performed on nturl log-trnsformed vlues. e One subject ws excluded due to insufficient phrmcokinetic smpling. AUC 0 24 h, re under the plsm concentrtion time curve during the dosing intervl; C mx, mximum plsm concentrtion; C 24 h, trough plsm concentrtion; NA, not pplicble; T mx, time to mximum plsm concentrtion; t 1/2, hlf-life. nd discontinued from the study. No serious dverse events were reported, nd there were no consistent, cliniclly relevnt, tretment-relted effects of dorvirine on vitl signs or ECGs. Study 2: 14 subjects reported totl of 104 nonserious clinicl dverse events. Of the 38 dverse events considered possibly relted to study drug, 30 occurred in subjects who received dorvirine: hedche (17), nuse (4), ftigue (2), somnolence (2), stomch discomfort (1), irritbility (1), musculoskeletl chest pin (1), neck pin (1) nd vomiting (1). All of the non-serious clinicl dverse events were mild or moderte in intensity nd of limited durtion. One serious dverse event of srcoidosis ws reported fter dministrtion of 750 mg dorvirine once dily for 7 dys. This event ws determined to be probbly not drug relted, due to medicl history of multiple preceding upper respirtory infections nd histopthologicl exmintion of enlrged medistinl lymph nodes biopsied during the study tht reveled grnuloms. The findings supported the investigtor s conclusion tht srcoidosis ws likely pre-existing condition. Overll, no cliniclly significnt trends or signls were observed in lbortory ssessments, vitl signs or ECGs. Discussion The sfety, tolerbility nd phrmcokinetics of dorvirine were investigted in two single- nd multiplescending dose studies tht explored wide rnge of doses (6 to 1,200 mg) in helthy mle subjects. Dorvirine ws rpidly bsorbed fter both single-dose nd multiple-dose dministrtion, with medin T mx vlues of 1 to 5 h post-dose. Therefter, concentrtions declined in single exponentil phse, with n pprent terminl hlf-life of 12 to 21 h. AUC nd C mx vlues incresed in slightly less thn dose-proportionl mnner fter both single- nd multiple-dose dministrtion. After multiple dys of once-dily dosing, most subjects chieved stedy stte by dy 7. The observed AUC 0 24 h ccumultion rtios of 1.2 to 1.4 correspond to men effective ccumultion hlf-life of pproximtely 9 to 14 h. For the NNRTI nd protese inhibitor clsses of ntiretrovirl gents, there is generl ssocition of efficcy with doses tht chieve trough concentrtion vlues exceeding the protein-djusted IC 95 in the HIV spred ssy, in which IC 95 is defined s the concentrtion t which repliction/reinfection of the virus in cell culture setting is inhibited by >95% in the presence of 50% norml humn serum [3]. These phrmcokinetic/phrmcodynmic reltionships hve been supported by experiments using n in vitro hollow-fibre biorector system where exposure of HIV-infected cells to ech inhibitor clss cn be crefully controlled over time [4]. Using time bove trough concentrtion s the key prmeter, popultion phrmcokinetic modelling for one novel NNRTI hs successfully predicted clinicl effects on HIV virl lod in Phse Ib proofof-concept study [5]. In the current study, single doses of dorvirine, 12 mg nd higher, resulted in geometric men C 24 h exceeding the in vitro IC 95 in 50% humn serum of not only wild-type virus (IC nm), but lso tht of severl common efvirenz resistnce muttions, including the double mutnt K103N/Y181C (IC nm). These trough levels were durbly sustined following multiple once-dily dosing. These results were utilized s one fctor in dose selection for the subsequent Phse II dose-rnging study in HIVinfected ptients [6]. After dministrtion of single 50-mg dose, only miniml mount of dorvirine ws excreted unchnged in the urine (6.3% over 24-h period), while men observed renl clernce ws low (9.43 ml/min). These results suggest tht urinry excretion is not mjor route of dorvirine elimintion. Administrtion of 50 mg dorvirine with high-ft mel ws ssocited with slight elevtions in AUC 0 nd C 24 h with no chnge in C mx. This food effect is unlikely to Interntionl Medicl Press

7 Sfety, tolerbility nd phrmcokinetics of dorvirine in helthy subjects Figure 2. Men dorvirine plsm concentrtion versus time profile following once dily orl doses of dorvirine, 30 to 750 mg, for 10 or 14 dys in helthy mle subjects 12,000 Men dorvirine plsm concentrtion, nm 10,000 8,000 6,000 4,000 2, mg 10 dys 60 mg 10 dys 120 mg 14 dys 240 mg 10 dys 450 mg 10 dys 750 mg 10 dys Dy Dy 1 Dy 10 or ,000 Men dorvirine plsm concentrtion, nm 10,000 1, Dy Dy 1 Dy 10 or 14 Upper plot: liner; lower plot: semi-log. be cliniclly meningful, lthough continued development will clrify phrmcokinetic/phrmcodynmic reltionships. In vitro studies predict tht dorvirine hs low potentil to be perpetrtor of drug interctions vi CYP metbolism. In the current study, midzolm exposure ws decresed by pproximtely 18% in the presence of dorvirine, while C mx remined unchnged with concomitnt dorvirine dministrtion. As midzolm is sensitive CYP3A4 substrte, these results support the position tht dorvirine is not significnt inhibitor of CYP3A4 metbolism nd lso suggest tht dorvirine my be wek inducer of CYP3A4. Antivirl Therpy

8 MS Anderson et l. Tble 7. Sttisticl comprison of phrmcokinetic prmeters fter midzolm 2 mg lone or with multiple orl doses of dorvirine 120 mg in helthy mles Prmeter Midzolm (n=8) Dorvirine + midzolm (n=7),b (Dorvirine + midzolm)/midzolm c AUC 0, ng/ml h d (19.40, 55.68) (15.90, 45.78) 0.82 (0.70, 0.97) C mx, ng/ml d 9.97 (6.83, 14.55) (6.90, 14.91) 1.02 (0.81, 1.28) T mx, h e 1.0 ( ) 0.5 ( ) Apprent terminl t 1/2, h f 3.81 (62.2) 3.41 (65.6) Vlues re geometric men (GM [95% CI]) unless otherwise indicted. b One subject hd missing phrmcokinetic dt when dorvirine nd midzolm were codministered. c Vlues re geometric men rtio (GMR [90% CI]). d Bck-trnsformed lest squres men nd CI from mixed effects model performed on nturl logtrnsformed vlues. e Vlues re medin (rnge). f Vlues re GM (geometric men percent coefficient of vrition [GCV]). GCV is clculted in the nturl log-scle with the eqution: 100 the squre root (exp(s 2 )-1), where s 2 is the observed vrince on the nturl log-scle. AUC 0, re under the plsm concentrtion time curve from time zero to infinity; C mx, mximum plsm concentrtion; T mx, time to mximum plsm concentrtion; t 1/2, hlf-life. In these two studies of helthy mle subjects, dorvirine ws generlly well tolerted when given orlly s single doses rnging from 6 to 1,200 mg nd s multiple doses rnging from 30 to 750 mg once dily for dys. One serious dverse event (srcoidosis) ws reported in subject receiving dorvirine 750 mg once dily, but ws judged probbly not relted to dorvirine. All of the non-serious clinicl dverse events were mild or moderte in intensity nd of limited durtion. No cliniclly significnt trends or signls were observed in clinicl lbortory ssessments, vitl signs or ECGs. In summry, the results of these studies indicte tht dorvirine is generlly well tolerted nd exhibits phrmcokinetic profile supportive of once-dily dosing. Trough concentrtions predictive of virologicl suppression of wild-type nd of common NNRTI-resistnt strins were chieved with single doses s low s 12 mg, nd were mintined over 10 dys of once-dily dosing. At stedy stte, dorvirine 120 mg did not hve significnt effect on midzolm exposure, consistent with in vitro studies suggesting tht dorvirine hs limited potentil for drug interctions medited by CYP3A4. These results support the further clinicl development of dorvirine s once-dily NNRTI. Bsed on the week 24 results of the Phse II, dose-finding study of dorvirine 25, 50, 100 nd 200 mg once dily in HIVinfected ptients, the 100-mg dose of dorvirine hs been selected for further development [6]. Acknowledgements We thnk the subjects who prticipted in this study, the clinicl reserch unit stff, nd Kryn Dvis nd Kim Strohmier (both of Merck & Co., Inc., Kenilworth, NJ, USA) for medicl writing ssistnce. Disclosure sttement This study ws sponsored nd funded by Merck, Shrp & Dohme Corp., subsidiry of Merck & Co., Inc. The study ws designed, mnged nd nlysed by the sponsor in conjunction with externl investigtors. Authors hd ccess to ll study dt upon request. All uthors pproved the finl version of the mnuscript for submission. The mnuscript ws lso reviewed by the sponsor. The opinions expressed in the mnuscript represent the collective views of the uthors nd do not necessrily reflect the officil position of Merck or the institutions ffilited with the cdemic uthors. LVB hs received grnts for clinicl tril conduct from Merck, Jnssen, GSK, Actogenix, Diichi-Snkyo, Menrini nd Ykult; speker fees from Novrtis, Jnssen, Recordti, nd AIM; nd conference support from Servier nd Diichi-Snkyo. The remining uthors re current or former employees of Merck & Co., Inc. nd my own stock nd/or stock options in the compny. Additionl file Additionl file 1: Men plsm concentrtion profiles of midzolm lone nd codministered with dorvirine 120 mg once dily in helthy mle subjects cn be found t documents/3365_anderson_addfile1.pdf References 1. de Béthune MP. Non-nucleoside reverse trnscriptse inhibitors (NNRTIs), their discovery, development, nd use in the tretment of HIV-1 infection: review of the lst 20 yers ( ). Antivirl Res 2010; 85: Li MT. Antivirl ctivity nd in vitro muttion development pthwys of MK-1439: novel non-nucleoside reverse trnscriptse inhibitor (NNRTI). Interscience Conference on Antimicrobil Agents & Chemotherpy (ICAAC) September 2012, Sn Frncisco, CA, USA. Abstrct H Vcc JP, Dorsey BD, Schleif WA, et l. L-735,524: n orlly biovilble humn immuno-deficiency virus type 1 protese inhibitor. Proc Ntl Acd Sci U S A 1994; 91: Bilello JA, Buer G, Dudley MN, Cole GA, Drusno GL. Effect of 2,3 -didehydro-3 -deoxythymidine in n in vitro hollow-fiber phrmcodynmic model system correltes with results of dose-rnging clinicl studies. Antimicrob Agents Chemother 1994; 38: Interntionl Medicl Press

9 Sfety, tolerbility nd phrmcokinetics of dorvirine in helthy subjects 5. Drusno GL, Moore KH, Kleim JP, Prince W, Bye A. Rtionl dose selection for nonnucleoside reverse trnscriptse inhibitor through use of popultion phrmcokinetic modeling nd Monte Crlo simultion. Antimicrob Agents Chemother 2002; 46: Accepted 31 October 2014; published online 3 December Morles-Rmirez JO, Gtell JM, Hgins DP, et l. Sfety & ntivirl effect of MK-1439, novel NNRTI, (+TDF/ FTC) in ART-nive HIV infected ptients. Conference on Retroviruses nd Opportunistic Infections (CROI). 3 6 Mrch 2014, Boston, MA, USA. Abstrct 92LB. Antivirl Therpy