Mechanism of Action: Biological response modifier. Rintatolimod is a synthetic mismatched double-stranded RNA toll-like receptor (TLR) agonist, having specificity for TLR-3. TLR-3, located in the endoplasm of certain immune cells, recognizes and responds to RNA virus infection. TLR-3 activation by natural or synthetic ligands induces cytokine secretion (such as type I interferon, TNF-α, IL-12, and MCP-1).3-5 Rintatolimod has also been described to activate RNase-L against viral RNA transcripts.5
Half-life (T½): Rintatolimod is reported to have a half-life of approximately 35 to 40 minutes.6
Metabolism/Elimination: Rintatolimod is rapidly metabolized (via hydrolysis) into naturally occurring inactive short RNA fragments and nucleotide precursors.6
Resistance: Rintatolimod has exhibited equal in vitro activity against wild-type HIV and HIV resistant to nevirapine, protease inhibitors, or nucleoside analogue reverse transcriptase inhibitors.7
Dosing in Clinical Trials
: AMP 720; NCT000358938
: Study investigating the role of rintatolimod in structured treatment interruption of ART
: HIV-infected, treatment-experienced adults with HIV RNA <50 copies/mL and CD4 count >400 cells/mm3
: Rintatolimod 400-mg IV infusions administered twice weekly, added to structured treatment interruptions of ART (up to three structured treatment interruptions over 64 weeks) versus no study drug intervention. Structured treatment interruption was discontinued when HIV RNA rebounded ≥5000 copies/mL for three consecutive weekly tests or ≥50,000 copies/mL once.8,9
(See references cited above for information on study results.)
: AMP 719; NCT0003558110
: Study evaluating the safety and efficacy of adding rintatolimod as an adjunct to ongoing ART
: HIV-infected, treatment-experienced adults with HIV RNA >500 and <30,000 copies/mL; CD4 count >300 cells/mm3
: Rintatolimod 200- to 400-mg IV infusions administered twice weekly for 24 weeks (in combination with ART) versus ART given alone.10
* This study was terminated.
Additional clinical trials of rintatolimod have also been completed.
In the AMP 720 study, adverse events associated with rintatolimod were described as generally mild and self-limiting. No adverse effects on lactic acid levels, insulin resistance, or hyperlipidemia were reported in patients receiving rintatolimod alone.9
Drug interactions related to rintatolimod use are currently unknown.
- United States National Library of Medicine. ChemIDplus Advanced. Available at: http://chem.sis.nlm.nih.gov/chemidplus/rn/38640-92-5. Last accessed on July 7, 2015.
- National Institute of Allergy and Infectious Diseases (NIAID). NIAID ChemDB, HIV Drugs in Development. Available at: http://chemdb.niaid.nih.gov/DrugDevelopmentHIV.aspx. Last accessed on July 7, 2015.
- Engel AL, Holt GE, Lu H. The pharmacokinetics of Toll-like receptor agonists and the impact on the immune system. Expert Rev Clin Pharmacol. 2011 Mar;4(2):275-89. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3105468/. Last accessed on July 7, 2015.
- Nicodemus CF, Berek JS. TLR3 agonists as immunotherapeutic agents. Immunotherapy. 2010 Mar;2(2):137-40. Available at: http://www.futuremedicine.com/doi/full/10.2217/imt.10.8. Last accessed on July 7, 2015.
- [No authors listed]. Mismatched double-stranded RNA: polyI:polyC12U. Drugs R D. 2004;5(5):297-304. Available at: http://www.ncbi.nlm.nih.gov/pubmed/15357629. Last accessed on July 7, 2015.
- Hemispherx Biopharma Inc. Arthritis Advisory Committee Meeting Briefing Document for the 20th December 2012 Meeting: AMPLIGEN® (rintatolimod; Poly I : Poly C12U) Treatment of Chronic Fatigue Syndrome NDA #22-151. Available at: http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/Drugs/ArthritisAdvisoryCommittee/UCM332517.pdf. Last accessed on July 7, 2015.
- Essey RJ, McDougall BR, Robinson WE Jr. Mismatched double-stranded RNA (polyI-polyC(12)U) is synergistic with multiple anti-HIV drugs and is active against drug-sensitive and drug-resistant HIV-1 in vitro. Antiviral Res. 2001 Sep;51(3):189-202. Available at: http://www.ncbi.nlm.nih.gov/pubmed/11448730. Last accessed on July 7, 2015.
- Hemispherx Biopharma. The Role of Ampligen in Strategic Therapeutic Intervention (STI) of Highly Active Anti-Retroviral Therapy (HAART): A Multi-Center, Randomized, Controlled Study of Ampligen Potentiation of the HAART-Free Interval. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on May 6, 2002. NLM Identifier: NCT00035893. Available at: https://www.clinicaltrials.gov/ct2/show/NCT00035893. Last accessed on July 7, 2015.
- Blick G, Greiger-Zanlungo P, Strayer DR, Mitchell WM, Carter WA. Interim Results of AMP720: A Phase IIb Prospective, Randomized, Controlled Study Evaluating the Immunomodulatory Role of Ampligen (Poly I:Poly C12U) Against HIV During STI. 2nd International AIDS Society (IAS) Conference on HIV Pathogenesis and Treatment; July 13-16, 2003; Paris, France. Abstract 596. Available at: https://www.iasociety.org/Abstracts/A10016.aspx. Last accessed on July 7, 2015.
- Hemispherx Biopharma. A Multi-Center, Randomized, Controlled Study of the Biological Actions of Ampligen as an Adjunct to HAART in HIV Disease. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered on May 3, 2002. NLM Identifier: NCT00035581. Available at: https://www.clinicaltrials.gov/ct2/show/NCT00035581. Last accessed on July 7, 2015.
Last Reviewed: July 7, 2015