Enzalutamide

Final results for the key secondary endpoint of overall survival (OS) from the PEACE-3 trial will be presented by the European Organization for Research and Treatment of Cancer (EORTC) coalition as an oral abstract at ASCO GU 2026. XOFIGO ® (radium-223 dichloride) in combination with enzalutamide reduced the risk of death by 24% (HR 0.76; 95% CI 0.60-0.96; p=0.0096) and a median OS of 38.2 months (95% CI 33.1-44.8) versus enzalutamide alone (32.6 months, 95% CI 29.3-38.2) in men with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases. WHIPPANY, N.J.--(BUSINESS WIRE)--Final results from the pivotal investigational Phase III PEACE-3 trial demonstrate that first-line treatment with XOFIGO® (radium-223 dichloride) in combination with enzalutamide, an androgen receptor pathway inhibitor (ARPI), resulted in a significant overall survival (OS) benefit, reducing the risk of death by 24% versus enzalutamide alone (hazard ratio [HR] 0.76; 95% confidence interval [CI] 0.60-0.96; p=0.0096) in men with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases.1 These data will be presented by the European Organization for Research and Treatment of Cancer (EORTC) coalition in an oral session at the American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU) 2026 (Oral abstract #15; February 26, 2026. 8:15 – 8:25 AM PST) and published simultaneously in Annals of Oncology. Updated results for radiological progression-free survival (rPFS), the primary endpoint of the trial, will also be shared. XOFIGO is indicated for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastatic disease.2 XOFIGO is not approved in this investigational indication in combination with enzalutamide. “Despite recent advances in prostate cancer care, many men with mCRPC and bone metastases continue to face a poor prognosis and a high risk of disease progression,” said Enrique Gallardo, MD, Parc Tauli Hospital Universitari, Sabadell, Spain and First Author and Presenter of the EORTC 1333/PEACE-3 trial. “Results from PEACE-3 show that starting with a combination of radium-223 and enzalutamide, may help support treatment strategies that prioritize bone health.” The PEACE-3 trial is an international, randomized, open-label, Phase III trial designed to investigate the efficacy and safety of XOFIGO in combination with enzalutamide in patients with mCRPC and bone metastases. The primary endpoint was rPFS by investigator assessment, with key secondary endpoints including OS, time to subsequent systemic treatment, pain progression, and symptomatic skeletal events. At the time of the final OS analysis, men receiving XOFIGO plus enzalutamide demonstrated a statistically significant improvement in the key secondary endpoint of OS compared to those receiving enzalutamide alone, with a 24% reduction in risk of death (HR 0.76; 95% CI 0.60-0.96; p=0.0096). Median OS was 38.2 months with XOFIGO plus enzalutamide versus 32.6 months with enzalutamide alone. The final OS results build on the primary analysis, published in Annals of Oncology, which showed a significant improvement in the primary endpoint of radiological progression-free survival (rPFS) with the combination versus enzalutamide alone (19.4 vs. 16.4 months respectively; HR 0.69; 95% CI 0.54–0.87; p=0.0009).3,4 “PEACE-3 is a strong example of how academic cooperative research can help advance progress for complex diseases such as metastatic prostate cancer,” said Denis Lacombe, Chief Executive Officer, European Organization for Research and Treatment of Cancer (EORTC). EORTC is a non-governmental, non-profit organization, which unites clinical cancer research experts, throughout Europe, to coordinate and conduct international translational and clinical research. “These Phase III data provide important insights for clinicians and underline the value of international collaboration in generating evidence that supports clinical decision-making.” “These new PEACE-3 data reinforce Bayer’s leadership in prostate cancer care and our long term commitment to addressing the unmet medical needs of patients,” said Christine Roth, Executive Vice President, Global Product Strategy and Commercialization and Member of the Pharmaceuticals Leadership Team at Bayer. “By investigating combination approaches, we are building a growing prostate cancer portfolio with the potential to bring new treatment options to patients across different stages of the disease.” Grade 3 or higher treatment emergent adverse events (TEAE) were recorded in 69% of patients in the combination arm versus 58% of patients treated with enzalutamide alone. No individual TEAE Grade 3 or higher has increased by more than 5% in the combination arm compared to the enzalutamide arm alone.1 About PEACE-3 (EORTC GUCG-1333)5 The PEACE-3 trial is an international, randomized, open-label, Phase III trial designed to investigate the efficacy and safety of XOFIGO in combination with enzalutamide in asymptomatic or mildly symptomatic patients (Brief Pain Inventory score <4) with metastatic castration-resistant prostate cancer (mCRPC) and ≥2 bone metastases. A total of 446 patients were randomized 1:1 to receive either XOFIGO 55 kBq/kg as an intravenous injection monthly for six cycles in combination with enzalutamide 160mg orally daily or enzalutamide 160mg orally daily. The primary endpoint was radiological progression-free survival (rPFS) by investigator assessment. Key secondary endpoints included overall survival (OS), time to subsequent systemic treatment, pain progression, and symptomatic skeletal event. This trial was a collaboration with several cancer cooperative groups: the European Organization for Research and Treatment of Cancer (EORTC), Clinical Trial Ireland (CTI), the Canadian Urological Oncology Group (CUOG), the Latin American Cooperative Oncology Group (LACOG), and French UNICANCER Urogenital Tumor Study Group (GETUG). The trial is supported by Astellas and Pfizer who manufacture enzalutamide (Xtandi) in collaboration with Bayer. About XOFIGO® (radium-223 dichloride) Injection2 XOFIGO is indicated for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastatic disease. Important Safety Information for XOFIGO® (radium-223 dichloride) Injection Warnings and Precautions: Bone Marrow Suppression: In the phase 3 ALSYMPCA trial, 2% of patients in the XOFIGO arm experienced bone marrow failure or ongoing pancytopenia, compared to no patients treated with placebo. There were two deaths due to bone marrow failure. For 7 of 13 patients treated with XOFIGO bone marrow failure was ongoing at the time of death. Among the 13 patients who experienced bone marrow failure, 54% required blood transfusions. Four percent (4%) of patients in the XOFIGO arm and 2% in the placebo arm permanently discontinued therapy due to bone marrow suppression. In the randomized trial, deaths related to vascular hemorrhage in association with myelosuppression were observed in 1% of XOFIGO-treated patients compared to 0.3% of patients treated with placebo. The incidence of infection-related deaths (2%), serious infections (10%), and febrile neutropenia (<1%) was similar for patients treated with XOFIGO and placebo. Myelosuppression–notably thrombocytopenia, neutropenia, pancytopenia, and leukopenia–has been reported in patients treated with XOFIGO. Monitor patients with evidence of compromised bone marrow reserve closely and provide supportive care measures when clinically indicated. Discontinue XOFIGO in patients who experience life-threatening complications despite supportive care for bone marrow failure Hematological Evaluation: Monitor blood counts at baseline and prior to every dose of XOFIGO. Prior to first administering XOFIGO, the absolute neutrophil count (ANC) should be ≥1.5 × 109/L, the platelet count ≥100 × 109/L, and hemoglobin ≥10 g/dL. Prior to subsequent administrations, the ANC should be ≥1 × 109/L and the platelet count ≥50 × 109/L. Discontinue XOFIGO if hematologic values do not recover within 6 to 8 weeks after the last administration despite receiving supportive care Concomitant Use With Chemotherapy: Safety and efficacy of concomitant chemotherapy with XOFIGO have not been established. Outside of a clinical trial, concomitant use of XOFIGO in patients on chemotherapy is not recommended due to the potential for additive myelosuppression. If chemotherapy, other systemic radioisotopes, or hemibody external radiotherapy are administered during the treatment period, XOFIGO should be discontinued Increased Fractures and Mortality in Combination With Abiraterone Plus Prednisone/Prednisolone: XOFIGO is not recommended for use in combination with abiraterone acetate plus prednisone/prednisolone outside of clinical trials. At the primary analysis of the Phase 3 ERA-223 study that evaluated concurrent initiation of XOFIGO in combination with abiraterone acetate plus prednisone/prednisolone in 806 asymptomatic or mildly symptomatic mCRPC patients, an increased incidence of fractures (28.6% vs 11.4%) and deaths (38.5% vs 35.5%) have been observed in patients who received XOFIGO in combination with abiraterone acetate plus prednisone/prednisolone compared to patients who received placebo in combination with abiraterone acetate plus prednisone/prednisolone. Safety and efficacy with the combination of XOFIGO and agents other than gonadotropin-releasing hormone analogues have not been established Embryo-Fetal Toxicity: The safety and efficacy of XOFIGO have not been established in females. XOFIGO can cause fetal harm when administered to a pregnant female. Advise pregnant females and females of reproductive potential of the potential risk to a fetus. Advise male patients to use condoms and their female partners of reproductive potential to use effective contraception during and for 6 months after completing treatment with XOFIGO Administration and Radiation Protection: XOFIGO should be received, used, and administered only by authorized persons in designated clinical settings. The administration of XOFIGO is associated with potential risks to other persons from radiation or contamination from spills of bodily fluids such as urine, feces, or vomit. Therefore, radiation protection precautions must be taken in accordance with national and local regulations Fluid Status: Dehydration occurred in 3% of patients on XOFIGO and 1% of patients on placebo. XOFIGO increases adverse reactions such as diarrhea, nausea, and vomiting, which may result in dehydration. Monitor patients’ oral intake and fluid status carefully and promptly treat patients who display signs or symptoms of dehydration or hypovolemia Injection Site Reactions: Erythema, pain, and edema at the injection site were reported in 1% of patients on XOFIGO Secondary Malignant Neoplasms: XOFIGO contributes to a patient’s overall long-term cumulative radiation exposure. Long-term cumulative radiation exposure may be associated with an increased risk of cancer and hereditary defects. Due to its mechanism of action and neoplastic changes, including osteosarcomas, in rats following administration of radium-223 dichloride, XOFIGO may increase the risk of osteosarcoma or other secondary malignant neoplasms. However, the overall incidence of new malignancies in the randomized trial was lower on the XOFIGO arm compared to placebo (<1% vs 2%; respectively), but the expected latency period for the development of secondary malignancies exceeds the duration of follow-up for patients on the trial Subsequent Treatment With Cytotoxic Chemotherapy: In the randomized clinical trial, 16% of patients in the XOFIGO group and 18% of patients in the placebo group received cytotoxic chemotherapy after completion of study treatments. Adequate safety monitoring and laboratory testing was not performed to assess how patients treated with XOFIGO will tolerate subsequent cytotoxic chemotherapy Adverse Reactions: The most common adverse reactions (≥10%) in the XOFIGO arm vs the placebo arm, respectively, were nausea (36% vs 35%), diarrhea (25% vs 15%), vomiting (19% vs 14%), and peripheral edema (13% vs 10%). Grade 3 and 4 adverse events were reported in 57% of XOFIGO-treated patients and 63% of placebo-treated patients. The most common hematologic laboratory abnormalities in the XOFIGO arm (≥10%) vs the placebo arm, respectively, were anemia (93% vs 88%), lymphocytopenia (72% vs 53%), leukopenia (35% vs 10%), thrombocytopenia (31% vs 22%), and neutropenia (18% vs 5%). Please see the full Prescribing Information for XOFIGO (radium Ra 223 dichloride). About Oncology at Bayer Bayer is committed to delivering science for a better life by advancing a portfolio of innovative treatments. The oncology franchise at Bayer includes seven marketed products and several other assets in various stages of clinical development. Together, these products reflect the company’s approach to research, which prioritizes targets and pathways with the potential to impact the way that cancer is treated. About Bayer Bayer is a global enterprise with core competencies in the life science fields of health care and nutrition. In line with its mission, “Health for all, Hunger for none,” the company’s products and services are designed to help people and the planet thrive by supporting efforts to master the major challenges presented by a growing and aging global population. Bayer is committed to driving sustainable development and generating a positive impact with its businesses. At the same time, the Group aims to increase its earning power and create value through innovation and growth. The Bayer brand stands for trust, reliability and quality throughout the world. In fiscal 2024, the Group employed around 93,000 people and had sales of 46.6 billion euros. R&D expenses amounted to 6.2 billion euros. For more information, go to www.bayer.com. © 2026 Bayer BAYER, the Bayer Cross and XOFIGO are registered trademarks of Bayer. Forward-Looking Statements This release may contain forward-looking statements based on current assumptions and forecasts made by Bayer management. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in Bayer’s public reports which are available on the Bayer website at www.bayer.com. The company assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments. References 1 Gallardo, E. et al. Final Overall Survival Results from the EORTC 1333/PEACE-3 Trial: Enzalutamide With or Without Radium-223 in Metastatic Castration-Resistant Prostate Cancer. Oral abstract #15. Presented at ASCO GU 2026. 2 Xofigo® (radium-223 dichloride) Injection [Prescribing Information]. Whippany, NJ: Bayer HealthCare Pharmaceuticals, December 2019. 3 Gillessen, S., et al. A randomized multicenter open label phase III trial comparing enzalutamide vs a combination of Radium-223 (Ra223) and enzalutamide in asymptomatic or mildly symptomatic patients with bone metastatic castration-resistant prostate cancer (mCRPC): First results of EORTC-GUCG 1333/PEACE-3. European Society of Medical Oncology 2025 (ESMO) LBA1. September 9, 2024 4 Tombal. B., et al. Enzalutamide plus Radium-223 in Metastatic Castration-Resistant Prostate Cancer: Results of the EORTC 1333/PEACE-3 trial. Annals of Oncology. May 30, 2025. DOI: 10.1016/j.annonc.2025.05.011 5 ClinicalTrials.gov NCT02194842. Phase III Radium 223 mCRPC-PEACE III (PEACE III). https://clinicaltrials.gov/study/NCT02194842. Accessed January 2026.

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