Zilebesiran

Last updated

Zilebesiran
Zilebesiran structure.svg
Clinical data
Other namesAD-85481, ALN-85481, ALN-AGT01
Legal status
Legal status
  • Investigational
Identifiers
  • sodium;[(2S,4R)-1-[12-[[1-[3-[3-[5-[(2R,3R,4R,5R,6R)-3-acetamido-4,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxypentanoylamino]propylamino]-3-oxopropoxy]-2-[[3-[3-[5-[(2R,3R,4R,5R,6R)-3-acetamido-4,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxypentanoylamino]propylamino]-3-oxopropoxy]methyl]-3-[3-[3-[5-[(2R,3R,4R,5R,6R)-3-acetamido-4,5-dihydroxy-6-methyloxan-2-yl]oxypentanoylamino]propylamino]-3-oxopropoxy]propan-2-yl]amino]-12-oxododecanoyl]-4-hydroxypyrrolidin-2-yl]methyl [(2R,3R,4R,5R)-5-(6-aminopurin-9-yl)-2-(hydroxymethyl)-4-methoxyoxolan-3-yl] phosphate
CAS Number
PubChem CID
UNII
Chemical and physical data
Formula C89H152N16NaO36P
Molar mass 2076.235 g·mol−1
3D model (JSmol)
  • C[C@@H]1[C@@H]([C@@H]([C@H]([C@@H](O1)OCCCCC(=O)NCCCNC(=O)CCOCC(COCCC(=O)NCCCNC(=O)CCCCO[C@H]2[C@@H]([C@H]([C@H]([C@H](O2)CO)O)O)NC(=O)C)(COCCC(=O)NCCCNC(=O)CCCCO[C@H]3[C@@H]([C@H]([C@H]([C@H](O3)CO)O)O)NC(=O)C)NC(=O)CCCCCCCCCCC(=O)N4C[C@@H](C[C@H]4COP(=O)([O-])O[C@@H]5[C@H](O[C@H]([C@@H]5OC)N6C=NC7=C(N=CN=C76)N)CO)O)NC(=O)C)O)O.[Na+]
  • InChI=InChI=1S/C89H153N16O36P.Na/c1-54-75(121)78(124)71(100-55(2)109)86(137-54)133-37-17-14-23-63(113)91-31-20-34-94-66(116)28-40-130-49-89(50-131-41-29-67(117)95-35-21-32-92-64(114)24-15-18-38-134-87-72(101-56(3)110)79(125)76(122)60(45-106)139-87,51-132-42-30-68(118)96-36-22-33-93-65(115)25-16-19-39-135-88-73(102-57(4)111)80(126)77(123)61(46-107)140-88)103-69(119)26-12-10-8-6-7-9-11-13-27-70(120)104-44-59(112)43-58(104)48-136-142(127,128)141-81-62(47-108)138-85(82(81)129-5)105-53-99-74-83(90)97-52-98-84(74)105;/h52-54,58-62,71-73,75-82,85-88,106-108,112,121-126H,6-51H2,1-5H3,(H,91,113)(H,92,114)(H,93,115)(H,94,116)(H,95,117)(H,96,118)(H,100,109)(H,101,110)(H,102,111)(H,103,119)(H,127,128)(H2,90,97,98);/q;+1/p-1/t54-,58+,59-,60-,61-,62-,71-,72-,73-,75+,76+,77+,78-,79-,80-,81-,82-,85-,86-,87-,88-;/m1./s1
  • Key:FUHMXNACFUZXIQ-ZHSRMXMESA-M

Zilebesiran (development code ALN-AGT01) is an investigational RNA interference (RNAi) therapeutic agent being developed by Roche and Alnylam Pharmaceuticals for the treatment of hypertension. [1] [2]

Contents

It is small interfering RNA that is administered subcutaneously twice annually to lower blood pressure in people already taking other antihypertensive drugs. [3] [4] [5] The drug is designed to inhibit hepatic angiotensinogen synthesis through targeted silencing of the angiotensinogen gene, offering the potential for prolonged blood pressure control with infrequent dosing. [1] [6] [7]

Mechanism of action

Zilebesiran works by targeting the hepatic production of angiotensinogen, which is the sole precursor of angiotensin peptides and plays a key role in the pathogenesis of hypertension. [1] The drug utilizes small interfering RNA (siRNA) technology to post-transcriptionally silence the angiotensinogen (AGT) gene in liver cells. [8]

The mechanism involves several steps: zilebesiran, conjugated with GalNAc (N-acetylgalactosamine), binds to the asialoglycoprotein receptor (ASGPR) on hepatocytes, enters endosomes, and releases the siRNA component which then binds to the RNA-induced silencing complex (RISC). [9] The siRNA guide strand hybridizes with AGT mRNA, leading to its degradation and ultimately reducing angiotensinogen protein synthesis. [9]

Clinical studies have shown that zilebesiran reduces serum angiotensinogen levels by more than 90%, leading to downstream reductions in the vasoconstrictor angiotensin II. [2] This approach targets the renin-angiotensin-aldosterone system at its most upstream point, potentially offering more comprehensive blockade than traditional ACE inhibitors or ARBs. [10]

Clinical development

Phase 1 studies

The first-in-human Phase 1 study of zilebesiran was a randomized, double-blind, placebo-controlled trial conducted in 107 patients with mild-to-moderate hypertension. [1] Results published in the New England Journal of Medicine in July 2023 demonstrated that single subcutaneous doses of zilebesiran led to dose-dependent decreases in both serum angiotensinogen levels and 24-hour ambulatory blood pressure that were maintained for up to 24 weeks. [1]

The study showed that doses of 200 mg or higher achieved sustained blood pressure reductions, with the 800 mg dose producing mean reductions in 24-hour systolic blood pressure of greater than 20 mmHg at six months. [11] Patients experienced consistent and sustained lowering of both daytime and nighttime systolic blood pressure throughout the six-month observation period. [11]

Phase 2 studies

KARDIA-1 trial

The KARDIA-1 Phase 2 trial was a randomized, double-blind, placebo-controlled, multicenter global dose-ranging study designed to evaluate the efficacy and safety of zilebesiran as monotherapy in adults with mild-to-moderate hypertension. [12] The study enrolled 394 adults representing a diverse population and evaluated multiple dose levels of zilebesiran compared to placebo. [12] [13]

KARDIA-2 trial

The KARDIA-2 study evaluated zilebesiran as an add-on therapy to standard of care antihypertensive medications. [10] Results announced in March 2024 demonstrated clinically significant blood pressure reductions when zilebesiran was added to existing antihypertensive regimens. [10] [14]

KARDIA-3 trial

The KARDIA-3 Phase 2 study is a randomized, double-blind, placebo-controlled, multicenter study designed to evaluate the efficacy and safety of zilebesiran used as an add-on therapy in adult patients with high cardiovascular risk. [15] [10] [16] Enrollment was completed in 2025, with the study evaluating zilebesiran in combination with at least two antihypertensives in patients with uncontrolled hypertension. [16]

Phase 3 studies

In September 2025, Roche and Alnylam advanced zilebesiran into a global phase III cardiovascular outcomes trial for people with uncontrolled hypertension. [17]

Clinical efficacy

Clinical trials have demonstrated that zilebesiran provides dose-dependent and sustained blood pressure reductions lasting up to 24 weeks after a single subcutaneous injection. [1] The KARDIA clinical program has enrolled more than 600 patients across Phase 2 trials, demonstrating clinically significant blood pressure reductions with encouraging safety profiles both as monotherapy and as add-on therapy. [18]

The drug achieves tonic blood pressure control with consistent and durable blood pressure reduction throughout a 24-hour period, sustained for months after a single dose. [19] This prolonged duration of action represents a potential paradigm shift in hypertension management, offering the possibility of infrequent dosing schedules compared to daily oral medications. [20]

Safety profile

Clinical trials have reported that zilebesiran has a satisfactory safety profile and is well tolerated by patients. [2] The most commonly observed adverse events were mild injection-site reactions at the subcutaneous injection site. [1] No serious adverse events directly attributable to zilebesiran have been reported in published studies. [1]

The safety profile appears favorable across the dose ranges studied, with higher doses showing proportionally greater efficacy without significant increases in adverse events. [18] The infrequent dosing schedule may also contribute to improved patient tolerability and adherence compared to daily oral antihypertensive medications. [20]

Technology platform

Zilebesiran utilizes Alnylam's Enhanced Stabilization Chemistry Plus (ESC+) GalNAc-conjugate technology, which enables targeted delivery to liver cells and enhanced stability of the siRNA molecule. [10] The GalNAc conjugation allows for specific uptake by hepatocytes through the asialoglycoprotein receptor, ensuring targeted delivery to the site of angiotensinogen synthesis. [9]

This technology platform represents an advancement in RNAi therapeutics, providing prolonged duration of action that distinguishes zilebesiran from traditional small molecule drugs targeting the renin-angiotensin-aldosterone system. [21]

Regulatory status

As of September 2025, zilebesiran remains an investigational drug that has not received approval from regulatory agencies. [16] The compound has completed through Phase 2 clinical development as part of the KARDIA clinical program, with plans for Phase 3 studies based on the positive results from earlier trials. [16]

See also

References

  1. 1 2 3 4 5 6 7 8 Desai, Akshay S.; Webb, David J.; Taubel, Jorg; Casey, Sarah; Cheng, Yansong; Robbie, Gabriel J.; et al. (20 July 2023). "Zilebesiran, an RNA Interference Therapeutic Agent for Hypertension". New England Journal of Medicine. 389 (3): 228–238. doi:10.1056/NEJMoa2208391. PMID   37467498.
  2. 1 2 3 "Zilebesiran — the first siRNA-based drug in hypertensiology: why is it needed, and will it change the treatment approach of hypertension?". Arterial Hypertension. 10 January 2024.
  3. Carvalho, Thiago (2023). "RNA interference treatment targeting angiotensinogen lowers blood pressure". Nature Medicine. 29 (12): 2962–2963. doi:10.1038/d41591-023-00091-x. ISSN   1078-8956. PMID   37845541.
  4. Khan, Rida S.; Frishman, William H. (22 February 2024). "Zilebesiran: A Promising Antihypertensive Therapy Inhibiting Angiotensinogen Synthesis". Cardiology in Review. 33 (3): 279–284. doi:10.1097/CRD.0000000000000645. PMID   38385680.
  5. Waldron, James (5 March 2024). "2nd win for Alnylam RNAi blood pressure med strengthens Roche's $2.8B biobucks bet". Fierce Biotech. Retrieved 6 March 2024.
  6. Desai, Akshay S.; Webb, David J.; Taubel, Jorg; Casey, Sarah; Cheng, Yansong; Robbie, Gabriel J.; et al. (20 July 2023). "Zilebesiran, an RNA Interference Therapeutic Agent for Hypertension" (PDF). New England Journal of Medicine. 389 (3): 228–238. doi:10.1056/NEJMoa2208391. hdl: 20.500.11820/9ec1c393-058a-4fe7-8e8f-df207dcdfb85 . PMID   37467498.
  7. Bakris, George L.; et al. (5 March 2024). "RNA Interference With Zilebesiran for Mild to Moderate Hypertension: The KARDIA-1 Randomized Clinical Trial". JAMA. 331 (9): 740–749. doi:10.1001/jama.2024.0728. PMC   10873804 . PMID   38363577.
  8. Khan, R. S.; Frishman, W. H. (2025). "Zilebesiran: A Promising Antihypertensive Therapy Inhibiting Angiotensinogen Synthesis". Cardiology in Review. 33 (3): 279–284. doi:10.1097/CRD.0000000000000645. PMID   38385680.
  9. 1 2 3 Siddiqui, E.; Siddiqui, A. H.; Moeed, A.; Laique, F.; Najeeb, H.; Al Hasibuzzaman, M. (2025). "Advancing hypertension management: the role of zilebesiran as an siRNA therapeutic agent". PMC. 87 (2): 577–582. doi:10.1097/MS9.0000000000002696. PMC   11918631 . PMID   40110301.
  10. 1 2 3 4 5 "Alnylam Reports Positive KARDIA-2 Topline Study Results". Alnylam Pharmaceuticals. 5 March 2024.
  11. 1 2 "Alnylam Presents New Data for Zilebesiran". Alnylam Pharmaceuticals. 13 November 2021.
  12. 1 2 "Alnylam Reports Positive Topline Results from KARDIA-1 Phase 2 Dose-Ranging Study". Alnylam Pharmaceuticals. 7 September 2023.
  13. Alnylam Pharmaceuticals (20 December 2024). A Randomized, Double-blind, Placebo-Controlled, Dose-Ranging Multicenter Study to Evaluate the Efficacy and Safety of ALN-AGT01 in Patients With Mild-to-Moderate Hypertension (Report). clinicaltrials.gov.
  14. Alnylam Pharmaceuticals (19 June 2025). A Randomized, Double-blind, Placebo-controlled, Multicenter Study to Evaluate the Efficacy and Safety of Zilebesiran Used as Add-on Therapy in Patients With Hypertension Not Adequately Controlled by a Standard of Care Antihypertensive Medication (Report). clinicaltrials.gov.
  15. Alnylam Pharmaceuticals (25 August 2025). A Randomized, Double-blind, Placebo-controlled, Multicenter Study to Evaluate the Efficacy and Safety of Zilebesiran Used as Add-on Therapy in Adult Patients With High Cardiovascular Risk and Hypertension Not Adequately Controlled by Standard of Care Antihypertensive Medications (Report). clinicaltrials.gov.
  16. 1 2 3 4 "Alnylam Highlights Significant Pipeline Progress". Alnylam Pharmaceuticals. 25 February 2025.
  17. "Roche and Alnylam to take zilebesiran into Phase III hypertension trial". www.thepharmaletter.com. Retrieved 3 September 2025.
  18. 1 2 "Alnylam Presents Positive Results from the KARDIA-2 Phase 2 Study". Alnylam Pharmaceuticals. 7 April 2024.
  19. "Alnylam Announces Publication of Phase 1 Study Results for Zilebesiran". Business Wire. 19 July 2023.
  20. 1 2 Lemine, M.; Almuzainy, S.; Aljubeh, R.; Alilo, A. (2024). "Zilebesiran and Hypertension: A Systematic Review and Meta-analysis". PMC. 36 (4): 420–430. PMC   11708905 . PMID   39781230.
  21. "ALN AGT 01". AdisInsight.