Clinical Pharmacology for Pifeltro
Mechanism Of Action
Doravirine is an antiretroviral drug [see Microbiology].
Pharmacodynamics
In a Phase 2 trial evaluating doravirine over a dose range of 0.25 to 2 times the recommended dose of PIFELTRO, (in combination with FTC/TDF) in participants living with HIV with no antiretroviral treatment history, no exposure-response relationship for efficacy was identified for doravirine.
Cardiac Electrophysiology
At a doravirine dose of 1200 mg, which provides approximately 4 times the peak concentration observed following the recommended dose of PIFELTRO, doravirine does not prolong the QT interval to any clinically relevant extent.
Pharmacokinetics
Doravirine pharmacokinetics are similar in healthy participants and participants living with HIV. Doravirine pharmacokinetics are provided in Table 7.
Table 7: Pharmacokinetic Properties of Doravirine
| Parameter |
Doravirine |
| General |
| Steady State Exposure*,† |
| AUC0-24 (mcg•h/mL) |
16.1 (29) |
| Cmax (mcg/mL) |
0.962 (19) |
| C24 (mcg/mL) |
0.396 (63) |
| Time to Steady State (Days) |
2 |
| Accumulation Ratio |
1.2 to 1.4 |
| Absorption |
| Absolute Bioavailability |
64% |
| Tmax (h) |
2 |
| Effect of Food‡ |
| AUC Ratio |
1.16 (1.06, 1.26) |
| Cmax Ratio |
1.03 (0.89, 1.19) |
| C24 Ratio |
1.36 (1.19, 1.55) |
| Distribution |
| Vdss (L)§ |
60.5 |
| Plasma Protein Binding |
76% |
| Elimination |
| t½ (h) |
15 |
| CL/F (mL/min)† |
106 (35.2) |
| CLrenal (mL/min)† |
9.3 (18.6) |
| Metabolism |
| Primary Pathway(s) |
CYP3A |
| Excretion |
| Major Route of Elimination |
Metabolism |
| Urine (unchanged) |
6% |
| Biliary/Fecal (unchanged) |
Minor |
Abbreviations: AUC=area under the time concentration curve; C max=maximum concentration; C24=concentration at 24 hours; Tmax time to Cmax ; Vdss = volume of distribution at steady state, t½=elimination half-life; CL/F=apparent clearance; CLrenal =apparent renal clearance
*Doravirine 100 mg once daily to participants living with HIV
†Presented as geometric mean (%CV: geometric coefficient of variation)
‡Geometric mean ratio [high-fat meal/fasting] and (90% confidence interval) for PK parameters. High fat meal is approximately 1,000 kcal, 50% fat. The effect of food is not clinically relevant.
§Based on IV dose |
Specific Populations
In adults, no clinically significant difference on the pharmacokinetics of doravirine were observed based on age (18 to 78 years of age), sex, and race/ethnicity, mild to severe renal impairment (creatinine clearance (CLcr) >15 mL/min, estimated by Cockcroft- Gault), or moderate hepatic impairment (Child-Pugh B). The pharmacokinetics of doravirine in patients with end-stage renal disease or undergoing dialysis, or severe hepatic impairment (Child-Pugh C) is unknown.
Patients With Renal Impairment
In a study comparing 8 participants with severe renal impairment to 8 participants without renal impairment, the single dose exposure of doravirine was 43% higher in participants with severe renal impairment. In a population pharmacokinetic analysis, renal function did not have a clinically relevant effect on doravirine pharmacokinetics. Doravirine has not been studied in patients with end-stage renal disease or in patients undergoing dialysis [see Use In Specific Populations].
Patients With Hepatic Impairment
No clinically significant difference in the pharmacokinetics of doravirine was observed in participants with moderate hepatic impairment (Child-Pugh score B) compared to participants without hepatic impairment. Doravirine has not been studied in participants with severe hepatic impairment (Child-Pugh score C) [see Use In Specific Populations].
Pediatric Patients
Mean doravirine exposures were similar in 54 pediatric participants aged 12 to less than 18 years and weighing at least 35 kg who received doravirine or DELSTRIGO in IMPAACT 2014 (Protocol 027) relative to adults following administration of doravirine or DELSTRIGO (Table 8). For pediatric participants weighing ≥ 35 kg and < 45 kg who received doravirine 100 mg or DELSTRIGO, the population pharmacokinetic modelpredicted mean C24 of doravirine was comparable to that achieved in adults, whereas mean AUC0-24 and Cmax of doravirine were 25% and 36% higher than adult values, respectively. However, the predicted AUC0-24 and Cmax increases are not considered clinically significant.
Table 8: Steady State Pharmacokinetics for Doravirine Following Administration of Doravirine or DELSTRIGO in Pediatric Participants Living with HIV Aged 12 to Less than 18 Years and Weighing at Least 35 kg
| Parameter* |
Doravirine† |
| AUC0-24 (mcg•h/mL) |
16.4 (24) |
| Cmax (mcg/mL) |
1.03 (16) |
| C24 (mcg/mL) |
0.379 (42) |
Abbreviations: AUC=area under the time concentration curve; Cmax =maximum concentration; C24 =concentration at 24 hours
* Presented as geometric mean (%CV: geometric coefficient of variation)
† From population PK analysis (n=53 weighing ≥45 kg, n=1 weighing ≥35 kg to <45 kg) |
Drug Interaction Studies
Doravirine is primarily metabolized by CYP3A, and drugs that induce or inhibit CYP3A may affect the clearance of doravirine. Co-administration of doravirine and drugs that induce CYP3A may result in decreased plasma concentrations of doravirine. Co- administration of doravirine and drugs that inhibit CYP3A may result in increased plasma concentrations of doravirine.
Doravirine is not likely to have a clinically relevant effect on the exposure of medicinal products metabolized by CYP enzymes. Doravirine did not inhibit major drug metabolizing enzymes in vitro, including CYPs 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4, and UGT1A1 and is not likely to be an inducer of CYP1A2, 2B6, or 3A4. Based on in vitro assays, doravirine is not likely to be an inhibitor of OATP1B1, OATP1B3, P-glycoprotein, BSEP, OAT1, OAT3, OCT2, MATE1, and MATE2K. Drug interaction studies were performed with doravirine and other drugs likely to be co-administered or commonly used as probes for pharmacokinetic interactions. The effects of co-administration with other drugs on the exposure (Cmax, AUC, and C24) of doravirine are summarized in Table 9. A single doravirine 100 mg dose was administered in these studies unless otherwise noted.
Table 9: Drug Interactions: Changes in Pharmacokinetic Parameter Values of Doravirine in the Presence of Co-administered Drug
| Co- administered Drug |
Regimen of Coadministered Drug |
N |
Geometric Mean Ratio (90% CI) of Doravirine Pharmacokinetics with/without Co-administered Drug (No Effect=1.00) |
| AUC* |
Cmax |
C24 |
| Azole Antifungal Agents |
| ketoconazole† |
400 mg QD |
10 |
3.06
(2.85, 3.29) |
1.25
(1.05, 1.49) |
2.75
(2.54, 2.98) |
| Antimycobacterials |
| rifampin |
600 mg QD |
10 |
0.12
(0.10, 0.15) |
0.43
(0.35, 0.52) |
0.03
(0.02, 0.04) |
| rifabutin |
300 mg QD |
12 |
0.50
(0.45, 0.55) |
0.99
(0.85, 1.15) |
0.32
(0.28, 0.35) |
| 300 mg QD‡ |
15 |
1.03
(0.94, 1.14) |
0.97
(0.87, 1.08) |
0.98
(0.88, 1.10) |
| HIV Antiviral Agents |
| ritonavir†,§ |
100 mg BID |
8 |
3.54
(3.04, 4.11) |
1.31
(1.17, 1.46) |
2.91
(2.33, 3.62) |
| efavirenz |
600 mg QD¶ |
17 |
0.38
(0.33, 0.45) |
0.65
(0.58, 0.73) |
0.15
(0.10, 0.23) |
| 600 mg QD# |
17 |
0.68
(0.58, 0.80) |
0.86
(0.77, 0.97) |
0.50
(0.39, 0.64) |
CI = confidence interval; QD = once daily; BID = twice daily
*AUC for single-dose, 0-∞ AUC0-24 for once daily.
†Changes in doravirine pharmacokinetic values are not clinically relevant.
‡Doravirine 100 mg BID resulted in similar pharmacokinetic values when compared to 100 mg QD without rifabutin.
§A single doravirine 50 mg dose (0.5 times the recommended approved dose) was administered.
¶The first day following the cessation of efavirenz therapy and initiation of doravirine 100 mg QD.
# 14 days following the cessation of efavirenz therapy and initiation of doravirine 100 mg QD. |
Based on drug interaction studies conducted with doravirine, no clinically significant drug interactions have been observed following the co-administration of doravirine and the following drugs: dolutegravir, ritonavir, TDF, lamivudine, elbasvir and grazoprevir, ledipasvir and sofosbuvir, ketoconazole, aluminum hydroxide/magnesium hydroxide/simethicone containing antacid, pantoprazole, atorvastatin, an oral contraceptive containing ethinyl estradiol and levonorgestrel, metformin, methadone, and midazolam.
Microbiology
Mechanism Of Action
Doravirine is a pyridinone non-nucleoside reverse transcriptase inhibitor of HIV-1 and inhibits HIV-1 replication by non-competitive inhibition of HIV-1 reverse transcriptase (RT). The inhibitory concentration at 50% (IC50) of doravirine for RNA-dependent DNA polymerization of recombinant wild-type HIV-1 RT in a biochemical assay was 12.2±2.0 nM (n=3). Doravirine does not inhibit the human cellular DNA polymerases α, β, and mitochondrial DNA polymerase γ.
Antiviral Activity In Cell Culture
Doravirine exhibited an EC50 value of 12.0±4.4 nM against wild-type laboratory strains of HIV-1 when tested in the presence of 100% normal human serum (NHS) using MT4-GFP reporter cells and a median EC50 value for HIV-1 subtype B primary isolates (n=118) of 4.1 nM (range: 1.0 nM-16.0 nM). Doravirine demonstrated antiviral activity against a broad panel of primary HIV-1 isolates (A, A1, AE, AG, B, BF, C, D, G, H) with EC50 values ranging from 1.2 nM to 10.0 nM.
Antiviral Activity In Combination With Other HIV Antiviral Agents
The antiviral activity of doravirine in cell culture was not antagonistic when combined with the NNRTIs delavirdine, efavirenz, etravirine, nevirapine, or rilpivirine; the NRTIs abacavir, didanosine, emtricitabine, lamivudine, stavudine, tenofovir DF, or zidovudine; the PIs darunavir or indinavir; the gp41 fusion inhibitor enfuvirtide; the CCR5 co-receptor antagonist maraviroc; or the integrase strand transfer inhibitor raltegravir.
Resistance
In Cell Culture
Doravirine-resistant strains were selected in cell culture starting from wild-type HIV-1 of different origins and subtypes, as well as NNRTI-resistant HIV-1. Observed emergent amino acid substitutions in RT included: V106A, V106I, V106M, V108I, H221Y, F227C, F227I, F227L, F227V, M230I, L234I, P236L, and Y318F. The V106A, V106M, V108I, H221Y, F227C, M230I, P236L, and Y318F substitutions conferred 3.4-fold to 70-fold reductions in susceptibility to doravirine. Y318F in combination with V106A, V106M, V108I, or F227C conferred greater decreases in susceptibility to doravirine than Y318F alone, which conferred a 10-fold reduction in susceptibility to doravirine.
In Clinical Trials
Clinical Trial Results In Adults With No Antiretroviral Treatment History
In the doravirine treatment arms of the DRIVE-FORWARD and DRIVE-AHEAD trials (n=747) through Week 96, 13 participants showed the emergence of doravirine resistance-associated substitutions in their HIV among 36 (36%) participants in the resistance analysis subset (participants with HIV-1 RNA greater than 400 copies per mL at virologic failure or early study discontinuation and having post-baseline resistance samples). Emergent doravirine resistance-associated substitutions in RT included one or more of the following: V90G/I, A98G, V106A, V106I, V106M/T, V108I, E138G, Y188L, H221Y, P225H, P225L, P225P/S, F227C, F227C/R, Y318Y/F and Y318Y/S. Eight of 13 (62%) participants with emergent doravirine resistance-associated substitutions showed doravirine phenotypic resistance and most of them had at least a 100-fold reduction in doravirine susceptibility (range >95- to >211–fold reduction in doravirine susceptibility). The other 5 virologic failures who had only amino acid mixtures of NNRTI resistance substitutions showed doravirine phenotypic fold-changes of less than 2-fold. Of the 36 participants in the resistance analysis subset, 10 participants (28%) developed genotypic and/or phenotypic resistance to the other drugs (abacavir, emtricitabine, lamivudine, or tenofovir) in the regimens of the DRIVE-FORWARD and DRIVE-AHEAD trials. The resistance-associated substitutions that emerged were RT M41L (n=1), A62A/V (n=1), K65R (n=2), T69T/A (n=1), V75V/I (n=1), and M184I or V (n=7).
In the DRV/r treatment arm of the DRIVE-FORWARD trial (n=383) through Week 96, no participants showed the emergence of darunavir resistance-associated substitutions among 15 participants with resistance data and 2 of the participants had emergent genotypic or phenotypic resistance to lamivudine or tenofovir. In the EFV/FTC/TDF treatment arm of the DRIVE-AHEAD trial (n=364) through Week 96, 15 participants showed the emergence of efavirenz resistance-associated substitutions among 25 (60%) participants in the resistance analysis subset and genotypic resistance to emtricitabine or tenofovir developed in 5 evaluable participants; emergent resistanceassociated substitutions were RT K65R (n=1), D67G/K70E (n=1), L74V/V75M/V118I (n=1), M184I or V (n=5), and K219K/E (n=1).
Clinical Trial Results In Virologically-Suppressed Adults
In the DRIVE-SHIFT clinical trial [see Clinical Studies], there were 6 participants in the immediate switch group (n=447) and 2 participants in the delayed switch group (n=209) who met the protocol-defined virologic failure criteria (confirmed HIV-1 RNA ≥ 50 copies/mL). Two of the 6 virologic failure participants in the immediate switch group had available resistance data and neither developed detectable genotypic or phenotypic resistance to doravirine, lamivudine, or tenofovir during treatment with DELSTRIGO. One of the two virologic failure participants in the delayed switch group who had available resistance data developed the RT M184M/I substitution and phenotypic resistance to emtricitabine and lamivudine during treatment with their baseline regimen.
Cross-Resistance
Cross-resistance has been observed among NNRTIs. Treatment-emergent doravirine resistance-associated substitutions can confer cross-resistance to efavirenz, etravirine, nevirapine, and rilpivirine. Of the 8 virologic failure participants who developed doravirine phenotypic resistance, all had phenotypic resistance to nevirapine, 6 had phenotypic resistance to efavirenz, 4 had phenotypic resistance to rilpivirine, and 4 had resistance to etravirine in the Monogram PhenoSense assay. Of the 11 virologic failure participants in DRIVE-AHEAD phenotypically resistant to efavirenz, 2 (18%) had decreased susceptibility to doravirine (18- and 36-fold).
The treatment-emergent doravirine resistance-associated substitution Y318F did not confer reduced susceptibility to efavirenz, etravirine, or rilpivirine.
A panel of 96 diverse clinical isolates containing NNRTI resistance-associated substitutions was evaluated for susceptibility to doravirine. Clinical isolates containing the Y188L substitution alone or in combination with K103N or V106I, V106A in combination with G190A and F227L, or E138K in combination with Y181C and M230L showed greater than 100-fold reduced susceptibility to doravirine.
Clinical Studies
Clinical Trial Results In Adults With No Antiretroviral Treatment History
The efficacy of PIFELTRO is based on the analyses of 96-week data from two randomized, multicenter, double-blind, active controlled Phase 3 trials (DRIVEFORWARD, NCT02275780 and DRIVE-AHEAD, NCT02403674) in participants living with HIV with no antiretroviral treatment history (n=1494).
In DRIVE-FORWARD, 766 participants were randomized and received at least 1 dose of either PIFELTRO once daily or darunavir 800 mg + ritonavir 100 mg (DRV+r) once daily each in combination with emtricitabine/tenofovir DF (FTC/TDF) or abacavir/lamivudine (ABC/3TC) selected by the investigator. At baseline, the median age of participants was 33 years, 16% were female, 27% were Non-White, 4% had hepatitis B and/or C virus coinfection, 10% had a history of AIDS, 20% had HIV-1 RNA greater than 100,000 copies/mL, 86% had CD4+ T-cell count greater than 200 cells/mm³, 13% received ABC/3TC, and 87% received FTC/TDF; these characteristics were similar between treatment groups.
In DRIVE-AHEAD, 728 participants were randomized and received at least 1 dose of either DELSTRIGO (DOR/3TC/TDF) or EFV 600 mg/FTC 200 mg/TDF 300 mg once daily. At baseline, the median age of participants was 31 years, 15% were female, 52% were Non-White, 3% had hepatitis B or C co-infection, 14% had a history of AIDS, 21% had HIV-1 RNA greater than 100,000 copies/mL, and 88% had CD4+ T-cell count greater than 200 cells/mm³; these characteristics were similar between treatment groups.
Week 96 outcomes for DRIVE-FORWARD and DRIVE-AHEAD are provided in Table 10. Side-by-side tabulation is to simplify presentation; direct comparisons across trials should not be made due to differing trial designs.
In DRIVE-FORWARD, the mean CD4+ T-cell counts in the PIFELTRO and DRV+r groups increased from baseline by 224 and 207 cells/mm³, respectively. In DRIVE-AHEAD, the mean CD4+ T-cell counts in the DELSTRIGO and EFV/FTC/TDF groups increased from baseline by 238 and 223 cells/mm , respectively.
Table 10: Virologic Outcome in DRIVE-FORWARD and DRIVE-AHEAD at Week 96 in HIV-1 Adults with No Antiretroviral Treatment History
| Outcome |
DRIVE-FORWARD |
DRIVE-AHEAD |
PIFELTRO + 2 NRTIs Once Daily
N=383 |
DRV+r + 2 NRTIs Once Daily
N=383 |
DELSTRIGO Once Daily
N=364 |
EFV/FTC/TDF Once Daily
N=364 |
| HIV-1 RNA <50 copies/mL |
72% |
65% |
77% |
74% |
| Treatment Differences (95% CI) * |
7.5% (1.0%, 14.1%) |
3.8% (-2.4%, 10.0%) |
| HIV-1 RNA ≥ 50 copies/mL† |
17% |
20% |
15% |
12% |
| No Virologic Data at Week 96 Window |
11% |
15% |
7% |
14% |
| Discontinued study due to AE or Death‡ |
2% |
4% |
3% |
8% |
| Discontinued study for Other Reasons§ |
7% |
9% |
4% |
5% |
| On study but missing data in window |
2% |
3% |
1% |
1% |
| Proportion (%) of Participants With HIV-1 RNA <50 copies/mL at Week 96 by Baseline and Demographic Category |
| Gender |
|
|
|
|
| Male |
72% (N = 319) |
67% (N = 326) |
78% (N = 305) |
73% (N = 311) |
| Female |
73% (N = 64) |
54% (N = 57) |
75% (N = 59) |
75% (N = 53) |
| Race |
| White |
78% (N = 280) |
68% (N = 280) |
80% (N = 176) |
74% (N = 170) |
| Non-White |
58% (N = 103) |
57% (N = 102) |
76% (N = 188) |
74% (N = 194) |
| Ethnicity¶ |
| Hispanic or Latino |
76% (N = 93) |
63% (N = 86) |
81% (N = 126) |
77% (N = 119) |
| Not Hispanic or Latino |
71% (N = 284) |
66% (N = 290) |
76% (N = 238) |
72% (N = 239) |
| NRTI Background Therapy |
| FTC/TDF |
71% (N = 333) |
64% (N = 335) |
- |
- |
| ABC/3TC |
80% (N = 50) |
67% (N = 48) |
- |
- |
| Baseline HIV-1 RNA (copies/mL) |
| ≤100,000 copies/mL |
75% (N = 300) |
66% (N = 309) |
80% (N = 291) |
77% (N = 282) |
| >100,000 copies/mL |
61% (N = 83) |
59% (N = 73) |
67% (N = 73) |
62% (N = 82) |
| CD4+ T-cell Count (cells/mm³) |
| ≤200 cells/mm³ |
62% (N = 42) |
51% (N = 67) |
59% (N = 44) |
70% (N = 46) |
| >200 cells/mm³ |
74% (N = 341) |
68% (N = 316) |
80% (N = 320) |
74% (N = 318) |
| Viral Subtype¶ |
| Subtype B |
71% (N = 266) |
66% (N = 272) |
80% (N = 232) |
72% (N = 253) |
| Subtype Non-B |
75% (N = 117) |
62% (N = 111) |
73% (N = 130) |
77% (N = 111) |
Note: NRTIs = FTC/3TC or ABC/3TC.
*The 95% CIs for the treatment differences were calculated using stratum-adjusted Mantel- Haenszel method.
† Includes participants who discontinued study drug or study before Week 96 for lack or loss of efficacy and participants with HIV-1 RNA equal to or above 50 copies/mL in the Week 96 window.
‡ Includes participants who discontinued because of adverse event (AE) or death if this resulted in no virologic data in the Week 96 window.
§ Other Reasons include: lost to follow-up, non-compliance with study drug, physician decision, pregnancy, protocol deviation, screen failure, withdrawal by participant.
¶ Does not include participants whose ethnicity or viral subtypes were unknown. |
Clinical Trial Results In Virologically-Suppressed Adults
The efficacy of switching from a baseline regimen consisting of two NRTIs in combination with a PI plus either ritonavir or cobicistat, or elvitegravir plus cobicistat, or an NNRTI to DELSTRIGO was evaluated in a randomized, open-label trial (DRIVE-SHIFT, NCT02397096), in virologically-suppressed adultsliving with HIV. Participants must have been virologically-suppressed (HIV-1 RNA < 50 copies/mL) on their baseline regimen for at least 6 months prior to trial entry, with no history of virologic failure. Participants were randomized to either switch to DELSTRIGO at baseline (n = 447, Immediate Switch Group (ISG)), or stay on their baseline regimen until Week 24, at which point they switched to DELSTRIGO (n = 223, Delayed Switch Group (DSG)).
At baseline, the median age of participants was 43 years, 16% were female, and 24% were Non-White, 21% were of Hispanic or Latino ethnicity, 3% had hepatitis B and/or C virus co-infection, 17% had a history of AIDS, 96% had CD4+ T-cell count greater than or equal to 200 cells/mm³, 70% were on a regimen containing a PI plus ritonavir, 24% were on a regimen containing an NNRTI, 6% were on a regimen containing elvitegravir plus cobicistat, and 1% were on a regimen containing a PI plus cobicistat; these characteristics were similar between treatment groups.
Virologic outcome results are shown in Table 11.
Table 11: Virologic Outcomes in DRIVE-SHIFT in HIV-1 Virologically- Suppressed Participants Who Switched to DELSTRIGO
| Outcome |
DELSTRIGO Once Daily ISG Week 48
N=447 |
Baseline Regimen DSG Week 24
N=223 |
| HIV-1 RNA ≥ 50 copies/mL* |
2% |
1% |
| ISG-DSG, Difference (95% CI)†,‡ |
0.7% (-1.3%, 2.6%) |
| HIV-1 RNA <50 copies/mL |
91% |
95% |
| No Virologic Data Within the Time Window |
8% |
4% |
| Discontinued study due to AE or Death§ |
3% |
<1% |
| Discontinued study for Other Reasons¶ |
4% |
4% |
| On study but missing data in window |
0 |
0 |
| Proportion (%) of Participants With HIV-1 RNA <50 copies/mL by Baseline and Demographic Category |
| Age (years) |
| < 50 |
90% (N = 320) |
95% (N = 157) |
| ≥ 50 |
94% (N = 127) |
94% (N = 66) |
| Gender |
| Male |
91% (N = 372) |
94% (N = 194) |
| Female |
91% (N = 75) |
100% (N = 29) |
| Race |
| White |
90% (N = 344) |
95% (N = 168) |
| Non-White |
93% (N = 103) |
93% (N = 55) |
| Ethnicity |
| Hispanic or Latino |
88% (N = 99) |
91% (N = 45) |
| Not Hispanic or Latino |
91% (N = 341) |
95% (N = 175) |
| CD4+ T-cell Count (cells/mm³) |
| <200 cells/mm³ |
85% (N = 13) |
75% (N = 4) |
| ≥200 cells/mm³ |
91% (N = 426) |
95% (N = 216) |
| Baseline Regimen# |
| PI plus either ritonavir or cobicistat |
90% (N=316) |
94% (N=156) |
| elvitegravir plus cobicistat or NNRTI |
93% (N = 131) |
96% (N=67) |
* Includes participants who discontinued study drug or study before Week 48 for ISG or before Week 24 for DSG for lack or loss of efficacy and participants with HIV-1 RNA ≥50 copies/mL in the Week 48 window for ISG and in the Week 24 window for DSG.
† The 95% CI for the treatment difference was calculated using stratum-adjusted Mantel- Haenszel method.
‡ Assessed using a non-inferiority margin of 4%.
§ Includes participants who discontinued because of adverse event (AE) or death if this resulted in no virologic data on treatment during the specified window.
¶ Other reasons include: lost to follow-up, non-compliance with study drug, physician decision, protocol deviation, withdrawal by participant.
# Baseline Regimen = PI plus either ritonavir or cobicistat (specifically atazanavir, darunavir, or lopinavir), or elvitegravir plus cobicistat, or NNRTI (specifically efavirenz, nevirapine, or rilpivirine), each administered with two NRTIs. |
Clinical Trial Results In Pediatric Participants
The efficacy of DELSTRIGO (DOR/3TC/TDF) was evaluated in cohort 2 of an open-label, single-arm 2-cohort trial in pediatric participants 12 to less than 18 years of age living with HIV (IMPAACT 2014 (Protocol 027), NCT03332095). In cohort 1, virologicallysuppressed participants (n=9) received a single 100 mg dose of PIFELTRO followed by intensive PK sampling. In cohort 2, virologically-suppressed participants (n=43) were switched to DELSTRIGO and treatment-naïve participants (n=2) were started on DELSTRIGO.
In cohort 2, at baseline the median age of participants was 15 years (range: 12 to 17), the median weight was 52 kg (range: 45 to 80), 58% were female, 78% were Asian and 22% were Black, and the median CD4+ T-cell count was 713 cells per mm³ (range 84 to 1397). After switching to DELSTRIGO, 95% (41/43) of virologically-suppressed participants remained suppressed (HIV-1 RNA <50 copies/mL) at Week 24. One of the two treatment-naïve participants achieved HIV-1 RNA <50 copies/mL at Week 24. The other treatment-naïve participant met the protocol-defined virologic failure criteria (defined as 2 consecutive plasma HIV-1 RNA test results ≥200 copies/mL at or after Week 24) and was evaluated for the development of resistance; no emergence of genotypic or phenotypic resistance to doravirine, lamivudine, or tenofovir was detected.