Islatravir

2026年2月25日，默沙东在2026年逆转录病毒和机会性感染会议（CROI 2026）上，以最新突破摘要形式公布了三项评估其研究性、每日一次、口服双药方案多拉韦林/islatravir（DOR/ISL， 100 mg/0.25 mg， MK-8591A）用于HIV-1成人患者的III期临床试验数据。数据显示，DOR/ISL是首个在48周时疗效非劣效于比克替拉韦/恩曲他滨/丙酚替诺福韦（BIC/FTC/TAF， 必妥维®*）且安全性相似的非整合酶链转移抑制剂（非INSTI）双药方案，并在已实现病毒学抑制的患者中展现了长达96周的持续疗效。 “我们很自豪能够在公司长达40年的HIV研究历史基础上继续前进，并在今年的CROI上展示我们HIV研发管线中令人信服的新数据，”默克研究实验室全球临床开发高级副总裁兼首席医学官Eliav Barr博士表示，“Islatravir通过包括抑制逆转录酶易位在内的多种机制阻断HIV-1复制，有潜力成为一系列每日和每周给药的双药、非INSTI治疗方案的基础药物。如果获批，DOR/ISL将成为我们产品组合中首个此类方案，可能为满足HIV感染者不断演变的治疗需求提供重要的新选择。”关键试验数据一览 初治患者中的疗效与安全性（试验MK-8591A-053）： 这项针对既往未接受过抗逆转录病毒治疗（初治）成人患者的III期双盲临床试验达到了其主要终点。第48周时，DOR/ISL组有91.8%的患者实现病毒抑制（HIV-1 RNA<50 copies/mL），而BIC/FTC/TAF组为90.6%（治疗差异1.2%， 95% CI： -3.7， 6.2， p<0.001），证明了DOR/ISL的非劣效性。 两组安全性特征相似，与既往研究一致。药物相关不良事件（AE）和因药物相关AE导致的停药率在两组间相当（DOR/ISL组分别为14%和1.1%， BIC/FTC/TAF组分别为18%和2.2%）。 值得注意的是，在基线高病毒载量（HIV-1 RNA>100，000 copies/mL 和 >500，000 copies/mL）的亚组患者中，DOR/ISL同样表现出高病毒抑制率，分别为94.0%和90.3%。 已抑制患者转换治疗的长期数据（试验MK-8591A-052）： 这项研究评估了从BIC/FTC/TAF方案转换至DOR/ISL的疗效。第48周主要终点结果显示，转换至DOR/ISL的患者中，有1.5%的患者病毒载量≥50 copies/mL，而继续使用BIC/FTC/TAF的患者中这一比例为0.6%（治疗差异0.9%， 95% CI -1.9， 2.9），证明其非劣效性。 第96周数据显示，疗效持续：DOR/ISL组有1.5%的患者病毒载量≥50 copies/mL，BIC/FTC/TAF组为1.2%（治疗差异0.3%， 95% CI -2.8， 2.4）；DOR/ISL组有88.9%的患者维持病毒学抑制（HIV-1 RNA<50 copies/mL），BIC/FTC/TAF组为90.1%（治疗差异-1.2%， 95% CI -6.5， 5.0）。 截至第96周，DOR/ISL的安全性与BIC/FTC/TAF相似，未发现新的安全性问题。 从多种基线方案转换的数据（试验MK-8591A-051）： 这项开放标签研究评估了从其他口服2药或3药抗逆转录病毒疗法（bART）转换至DOR/ISL的疗效。第48周时，DOR/ISL组有1.4%的患者病毒载量≥50 copies/mL，而继续bART组为4.9%（治疗差异-3.6%， 95% CI -7.8， -0.8），证明DOR/ISL非劣效于bART。 第96周时，持续使用DOR/ISL 96周的患者中，有1.9%的患者病毒载量≥50 copies/mL；而在第48周从bART转换至DOR/ISL的患者中，这一比例为1.1%。 两组在药物相关AE和因AE导致的停药率方面相似。监管进展与研发前景 基于MK-8591A-051和-052试验的48周数据，默克已向美国FDA提交了DOR/ISL用于在稳定抗逆转录病毒方案下实现病毒学抑制的成人HIV-1感染者的新药申请（NDA）。根据《处方药使用者付费法案》（PDUFA），FDA的目标审评日期设定为2026年4月28日。 此外，islatravir作为核心药物，正在与吉利德的来那卡帕韦联合开发为口服每周一次疗法（III期试验ISLEND-1和ISLEND-2），并与默克在研的非核苷类逆转录酶抑制剂ulonivirine（MK-8507）联合开发为口服每周一次疗法（IIb期试验）。默克还在开发其研究性每月一次口服候选药物MK-8527，用于HIV-1暴露前预防（PrEP），相关III期试验（EXPrESSIVE-10和-11）正在进行中。关于药物成分与安全性 Islatravir（MK-8591）是默克在研的核苷类似物，通过包括抑制逆转录酶易位在内的多种机制阻断HIV-1复制。多拉韦林是一种已获批的非核苷类逆转录酶抑制剂。 新闻稿同时回顾了已获批药物PIFELTRO®（多拉韦林）和DELSTRIGO®（多拉韦林/拉米夫定/富马酸替诺福韦二吡呋酯）的适应症和重要的安全性信息，包括乙型肝炎严重急性加重风险、禁忌症（与强CYP3A诱导剂合用）、严重皮肤反应、新发或加重的肾功能损害、骨密度下降等。 *必妥维®（BIC/FTC/TAF）是吉利德科学公司的注册商标。 立即扫码加入药事纵横交流群

DOR/ISL is the first non-INSTI, two-drug regimen to demonstrate non-inferiority and a similar safety pro Week 48 to BIC/FTC/TAF in adults living with HIV-1 who had not previously received antiretroviral treatment DOR/ISL maintained virologic suppression at Week 96 in adults with virologically suppressed HIV-1 who switched from other oral antiretroviral therapies, including BIC/FTC/TAF RAHWAY, N.J.--(BUSINESS WIRE)-- $MRK #MRK --Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced the presentation of results from three pivotal Phase 3 trials evaluating the investigational, once-daily, oral, two-drug regimen of doravirine/islatravir [DOR/ISL (100 mg/0.25 mg), (MK-8591A)] in adults with HIV-1. The findings were shared in late-breaking presentations at the 33rd Conference on Retroviruses and Opportunistic Infections (CROI) being held in Denver. “We are proud to continue building on our 40-year history of HIV research with the presentation of compelling new data from our HIV pipeline at CROI this year,” said Dr. Eliav Barr, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories. “Islatravir blocks HIV-1 replication through multiple mechanisms, including reverse transcriptase translocation inhibition, and could serve as the anchor for a series of two-drug, non-INSTI, daily and weekly treatment regimens. If approved, DOR/ISL will be the first of these regimens in our portfolio and may provide an important new option to help meet the evolving treatment needs of people living with HIV.” The Phase 3, double-blind, clinical trial MK-8591A-053 evaluating DOR/ISL versus bictegravir/emtricitabine/tenofovir alafenamide i [(50 mg/200 mg/25 mg),(BIC/FTC/TAF)] in adults living with HIV-1 who had not previously received antiretroviral treatment (treatment-naïve), met its primary efficacy endpoint of percentage of participants achieving viral suppression (HIV-1 RNA 100,000 copies/mL). The primary efficacy endpoint was the percentage of participants with HIV-1 RNA 100,000 copies/mL, 10.3% had HIV-1 RNA >500,000 copies/mL and 17.2% had baseline CD4+ T-cell count 100,000 copies/mL (94.0% vs 87.6%, respectively) and >500,000 copies/mL (90.3% vs 84.4%, respectively). Drug-related AEs were reported in 14.1% of participants on DOR/ISL and 18.0% on BIC/FTC/TAF and discontinuations due to AEs (1.1% vs. 2.2%) were similar in both groups. Immune reconstitution was similar in DOR/ISL vs. comparator with no between-group differences in mean increases in CD4+ T-cell counts or total lymphocyte counts (TLC). About the Phase 3 data from MK-8591A-052 MK-8591A-052 is a Phase 3, randomized, active-controlled, double-blind, clinical trial to evaluate the efficacy and safety of a switch to investigational, once-daily DOR/ISL (100 mg/0.25 mg) in adults with HIV-1 infection that has been virologically suppressed on BIC/FTC/TAF (50 mg/200 mg/25 mg). In this trial, 513 adults with HIV-1 who had virologic suppression for three months or more on BIC/FTC/TAF, no history of treatment failure and no known resistance to DOR were randomized (2:1) and switched to DOR/ISL (n= 342) or continued treatment with BIC/FTC/TAF (n=171). The primary efficacy endpoint, the percentage of participants with HIV-1 RNA ≥50 copies/mL at Week 48 (non-inferiority margin 4%), was met, demonstrating non-inferiority to BIC/FTC/TAF; 1.5% of participants who switched to DOR/ISL had a viral load of ≥50 copies/mL at Week 48, compared to 0.6% on BIC/FTC/TAF (treatment difference 0.9%, 95% CI -1.9, 2.9). Results at Week 48 were recently published in The Lancet . At Week 96, DOR/ISL continued to demonstrate similar efficacy compared to BIC/FTC/TAF; 1.5% of participants on DOR/ISL had a viral load of ≥50 copies/mL compared to 1.2% of participants on BIC/FTC/TAF (treatment difference 0.3%, 95% CI -2.8, 2.4); 88.9% of participants on DOR/ISL maintained virologic suppression (HIV-1 RNA <50 copies/mL) compared to 90.1% of participants continuing BIC/FTC/TAF (treatment difference -1.2%, 95% CI -6.5, 5.0). No hypothesis testing was performed for these secondary endpoints. The safety pro DOR/ISL at Week 96 continued to be similar to BIC/FTC/TAF with no new safety findings. No additional drug-related serious adverse events were reported in any group between Week 48 and Week 96. At Week 96, rates of discontinuation due to AEs were similar for both groups (3.2% vs. 2.9%). There were no differences between trial arms in CD4+ T-cell count or TLC changes through Week 96. About the Phase 3 data from MK-8591A-051 MK-8591A-051 is a Phase 3, open-label randomized, active-controlled, clinical trial to evaluate the efficacy and safety of a switch to investigational, once-daily DOR/ISL (100 mg/0.25 mg) in adults with HIV-1 infection that has been virologically suppressed using bART. In this trial, 551 adults with HIV-1 RNA <50 copies/mL for three months or more on oral 2- or 3-drug ART, with no history of treatment failure and no known virologic resistance to DOR, were randomized 2:1 and switched to DOR/ISL (n= 366) or continued bART (n=185), stratified by bART regimen. The primary efficacy endpoint, percentage of participants with HIV-1 RNA ≥50 copies/mL at Week 48 (non-inferiority margin 4%), was met, demonstrating DOR/ISL to be non-inferior to bART; 1.4% of participants who received DOR/ISL had a viral load of ≥50 copies/mL at Week 48, compared to 4.9% on bART (treatment difference -3.6%, 95% CI -7.8, -0.8). After Week 48 of the comparative portion of the study, all participants received open-label DOR/ISL through Week 144. Results at Week 48 were recently published in The Lancet . At Week 96, 1.9% of participants who continued on DOR/ISL for 96 weeks had HIV-1 RNA ≥50 copies/mL and 1.1% of participants who switched from bART to DOR/ISL at Week 48. Additionally, 92.6% of participants who were on DOR/ISL through 96 weeks and 96.6% of participants who switched to DOR/ISL at Week 48 maintained virologic suppression (HIV-1 RNA <50 copies/mL) at Week 96. At Week 96, there were similar rates of drug-related AEs between those who continued on DOR/ISL (13.7%) for 96 weeks and for those who switched from bART to DOR/ISL at Week 48 (11.3%) and rates of discontinuations due to AEs for those on DOR/ISL for 96 weeks (1.1%) and for those who switched from bART to DOR/ISL at Week 48 (0.6%) were similar. The mean percent change in total lymphocyte and CD4 counts were similar for participants who continued on DOR/ISL and switched from bART to DOR/ISL. No participants discontinued treatment due to decreased CD4+ T-cell count or TLC. About Islatravir (MK-8591) and Merck’s HIV Research Islatravir (MK-8591) is Merck’s investigational nucleoside analog that blocks HIV-1 replication by multiple mechanisms including inhibition of reverse transcriptase translocation, resulting in immediate chain termination and induction of structural changes in the viral DNA. Islatravir is under evaluation in multiple ongoing early and late-stage clinical trials in combination with other antiretrovirals for potential daily and once-weekly treatments for HIV-1, with islatravir serving as the anchor medicine in these two-drug regimens. Islatravir in combination with Gilead’s lenacapavir is in Phase 3 development as a novel oral once-weekly treatment for HIV-1 [ISLEND-1 ( NCT06630286 ) and ISLEND-2 ( NCT06630299 )], and islatravir in combination with our company’s investigational non-nucleoside reverse transcriptase inhibitor (NNRTI) ulonivirine (MK-8507) is in Phase 2b development (MK-8591B-060, NCT06891066 and MK-8591B-062, NCT07266831 ) as an oral once-weekly treatment. MK-8527 is the company’s investigational, novel, once-monthly, oral candidate for pre-exposure prophylaxis (PrEP) for HIV-1. The Phase 3 EXPrESSIVE-11 (MK-8527-011, NCT07044297 ) trial is evaluating the safety and efficacy of MK-8527 as PrEP to reduce the risk of sexually acquired HIV-1 infection among people likely to be exposed to HIV-1 in 16 countries. The Phase 3 EXPrESSIVE-10 (MK-8527-010, NCT07071623 ) trial is evaluating the safety and efficacy of MK-8527 as PrEP to reduce the risk of sexually acquired HIV-1 infection among women and adolescent girls in sub-Saharan Africa. Both trials are now enrolling. For an overview of Merck’s HIV treatment and prevention clinical development program, please click here . Indications and usage for PIFELTRO ® (doravirine) and DELSTRIGO ® (doravirine, lamivudine, and tenofovir disoproxil fumarate) in the U.S. PIFELTRO is indicated in combination with other antiretroviral (ARV) agents for the treatment of HIV-1 infection in adult patients with no prior ARV treatment history or to replace the current ARV regimen in those who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable ARV regimen with no history of treatment failure and no known substitutions associated with resistance to doravirine. DELSTRIGO is indicated as a complete regimen for the treatment of HIV-1 infection in adult patients with no prior ARV treatment history or to replace the current ARV regimen in those who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable ARV regimen with no history of treatment failure and no known substitutions associated with resistance to the individual components of DELSTRIGO. Selected Safety Information Warning: Posttreatment Acute Exacerbation of Hepatitis B Virus (HBV) for DELSTRIGO All patients with HIV-1 should be tested for the presence of HBV before initiating ARV therapy. Severe acute exacerbations of HBV have been reported in people with concomitant HIV-1 and HBV who have discontinued products containing lamivudine or tenofovir disoproxil fumarate (TDF), which are components of DELSTRIGO. Patients coinfected with HIV-1 and HBV who discontinue DELSTRIGO should be monitored with both clinical and laboratory follow-up for at least several months after stopping DELSTRIGO. If appropriate, initiation of anti-HBV therapy may be warranted. Contraindications PIFELTRO and DELSTRIGO are contraindicated when coadministered with drugs that are strong cytochrome P450 (CYP)3A enzyme inducers (including the anticonvulsants carbamazepine, oxcarbazepine, phenobarbital, and phenytoin; the androgen receptor inhibitor enzalutamide; the antimycobacterials rifampin and rifapentine; the cytotoxic agent mitotane; and the herbal product St. John’s wort (Hypericum perforatum)), as significant decreases in doravirine plasma concentrations may occur, which may decrease the effectiveness of DELSTRIGO and PIFELTRO. DELSTRIGO is contraindicated in patients with a previous hypersensitivity reaction to lamivudine. Warnings and Precautions Severe Skin Reactions Severe skin reactions, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), have been reported during the postmarketing experience with doravirine-containing regimens. Discontinue PIFELTRO or DELSTRIGO, and other medications known to be associated with severe skin reactions, immediately if a painful rash with mucosal involvement or a progressive severe rash develops. Clinical status should be closely monitored, and appropriate therapy should be initiated. New or Worsening Renal Impairment Renal impairment, including cases of acute renal failure and Fanconi syndrome, have been reported with the use of TDF. DELSTRIGO should be avoided with concurrent or recent use of a nephrotoxic agent (e.g., high-dose or multiple NSAIDs). Cases of acute renal failure after initiation of high-dose or multiple NSAIDs have been reported in people living with HIV with risk factors for renal dysfunction who appeared stable on TDF. Prior to or when initiating DELSTRIGO, and during treatment, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus. Discontinue DELSTRIGO in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome. Discontinue DELSTRIGO if estimated creatinine clearance declines below 50 mL/min. Bone Loss and Mineralization Defects In clinical trials in adults living with HIV, TDF was associated with slightly greater decreases in bone mineral density (BMD) and increases in biochemical markers of bone metabolism. Serum parathyroid hormone levels and 1,25 Vitamin D levels were also higher. Cases of osteomalacia associated with proximal renal tubulopathy have been reported with the use of TDF. The effects of TDF-associated changes in BMD and biochemical markers on long-term bone health and future fracture risk in adults are unknown. Immune Reconstitution Syndrome Immune reconstitution syndrome can occur, including the occurrence of autoimmune disorders with variable time to onset, which may necessitate further evaluation and treatment. Drug Interactions Because DELSTRIGO is a complete regimen, coadministration with other antiretroviral medications for the treatment of HIV-1 infection is not recommended. Coadministration of PIFELTRO with efavirenz, etravirine, or nevirapine is not recommended. If DELSTRIGO is coadministered with rifabutin, take one tablet of DELSTRIGO once daily, followed by one tablet of doravirine (PIFELTRO) approximately 12 hours after the dose of DELSTRIGO. If PIFELTRO is coadministered with rifabutin, increase PIFELTRO dosage to one tablet twice daily (approximately 12 hours apart). Consult the full Prescribing Information prior to and during treatment for more information on potential drug-drug interactions. Dosage and Administration/Specific Populations Renal Impairment Because DELSTRIGO is a fixed-dose combination tablet and the dosage of lamivudine and TDF cannot be adjusted, DELSTRIGO is not recommended in patients with estimated creatinine clearance less than 50 mL/min. Adverse Reactions The most common adverse reactions with DELSTRIGO (incidence ≥5%, all intensities) were dizziness (7%), nausea (5%), and abnormal dreams (5%). The most common adverse reactions with PIFELTRO (incidence ≥5%, all intensities) were nausea (7%), dizziness (7%), headache (6%), fatigue (6%), diarrhea (6%), abdominal pain (5%), and abnormal dreams (5%). By week 96 in DRIVE-FORWARD, 2% of adult participants in the PIFELTRO group and 3% in the darunavir+ritonavir (DRV+r) group had adverse events leading to discontinuation of study medication. By week 96 in DRIVE-AHEAD, 3% of adult participants in the DELSTRIGO group and 7% in the efavirenz (EFV)/emtricitabine (FTC)/TDF group had adverse events leading to discontinuation of study medication. In DRIVE-FORWARD, mean changes from baseline at week 48 in LDL-cholesterol (LDL-C) and non-HDL-cholesterol (non-HDL-C) were pre-specified. LDL-C: -4.6 mg/dL in the PIFELTRO group vs 9.5 mg/dL in the DRV+r group. Non-HDL-C: -5.4 mg/dL in the PIFELTRO group vs 13.7 mg/dL in the DRV+r group. The clinical benefits of these findings have not been demonstrated. In DRIVE-AHEAD, mean changes from baseline at week 48 in LDL-C and non-HDL-C were pre-specified. LDL-C: -2.1 mg/dL in the DELSTRIGO group vs 8.3 mg/dL in the EFV/FTC/TDF group. Non-HDL-C: -4.1 mg/dL in the DELSTRIGO group vs 12.7 mg/dL in the EFV/FTC/TDF group. The clinical benefits of these findings have not been demonstrated. In DRIVE-SHIFT, mean changes from baseline at week 24 in LDL-C and non-HDL-C were pre-specified. LDL-C: -16.3 mg/dL in the DELSTRIGO group vs -2.6 mg/dL in the PI + ritonavir group. Non-HDL-C: -24.8 mg/dL in the DELSTRIGO group vs -2.1 mg/dL in the PI + ritonavir group. The clinical benefits of these findings have not been demonstrated. In DRIVE-AHEAD, neuropsychiatric adverse events were reported in the three pre-specified categories of sleep disorders and disturbances, dizziness, and altered sensorium. Twelve percent of adult participants in the DELSTRIGO group and 26% in the EFV/FTC/TDF group reported neuropsychiatric adverse events of sleep disorders and disturbances; 9% in the DELSTRIGO group and 37% in the EFV/FTC/TDF group reported dizziness; and 4% in the DELSTRIGO group and 8% in the EFV/FTC/TDF group reported altered sensorium. The safety of DELSTRIGO in virologically suppressed adults was based on week 48 data from participants in the DRIVE-SHIFT trial. Overall, the safety pro virologically suppressed adult participants was similar to that in participants with no ARV treatment history. Serum ALT and AST Elevations: In the DRIVE-SHIFT trial, 22% and 16% of participants in the immediate switch group experienced ALT and AST elevations greater than 1.25 X ULN, respectively, through 48 weeks on DELSTRIGO. For these ALT and AST elevations, no apparent patterns with regard to time to onset relative to switch were observed. One percent of participants had ALT or AST elevations greater than 5 X ULN through 48 weeks on DELSTRIGO. The ALT and AST elevations were generally asymptomatic, and not associated with bilirubin elevations. In comparison, 4% and 4% of participants in the delayed switch group experienced ALT and AST elevations of greater than 1.25 X ULN through 24 weeks on their baseline regimen. Pregnancy/Breastfeeding There is a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to PIFELTRO or DELSTRIGO during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Inform individuals with HIV-1 infection of the potential risks of breastfeeding, including: (1) HIV-1 transmission (in HIV-1–negative infants), (2) developing viral resistance (in HIV-1–positive infants), and (3) serious adverse reactions in a breastfed infant similar to those seen in adults. Merck’s Commitment to HIV For 40 years, Merck has been committed to scientific research and discovery in HIV leading to scientific breakthroughs that have helped change HIV treatment. Our work has been pioneering in the development of new options across multiple drug classes to help those impacted by HIV. Today, we are developing a series of antiviral options designed to help people manage HIV and protect people from HIV. We are researching for real life and want to ensure people are not defined by HIV. Our work focuses on transformational innovations, collaborations with others in the global HIV community, and access initiatives aimed at the goal of helping to end the HIV epidemic for everyone. About Merck At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit and connect with us on X (formerly Twitter) , Facebook , Instagram , YouTube and LinkedIn . Forward-Looking Statement of Merck & Co., Inc., Rahway, N.J., USA This news release of Merck & Co., Inc., Rahway, N.J., USA (the “company”) includes “forward-looking statements” within the meaning of the safe harbor provisions of the U. Contacts Media Contacts: Eilyn Segura (203) 940-6259 Deb Wambold (215) 779-2234 Investor Contacts: Peter Dannenbaum (732) 594-1579 Damini Chokshi (732) 594-1577 Read full story here