HEP-1 Research

HEP-1 research sits in an unusual position. The peptide is the active substance of Gepon, a medicine registered in Russia ^[19]. The published evidence for it is small and mostly uncontrolled, and no efficacy finding in it has been independently replicated.

What HEP-1 is

HEP-1 is an unmodified synthetic peptide of fourteen amino acids, sequence TEKKRRETVEREKE, matching the hinge region of human ezrin (UniProt P15311). PubChem resolves the names HEP-1 and Gepon to one record, CID 25078222, carrying CAS 174641-44-2, formula C74H132N26O27 and molecular weight 1818.0 ^[18]. Purepeptides lists it as research-grade HEP-1. Research-grade material is not a medicine and is not for human consumption.

Several names resemble this compound without being it. Ezrin itself is a 586-residue protein with a very large literature, and a 14-residue fragment inherits none of it. RepG3, sequence GEKKRRETVEREGG, is a separate derivative from the same inventors and returns no PubChem record ^[18]. HEP1 is also the symbol for the unrelated human gene DNLZ, and Hep-1 names a hepatoma cell line.

Regulatory status

HEP-1 is registered as a medicine in Russia under a genuine marketing authorization ^[19]. The authorization holder's approved instruction site publishes registration number Р N000015/01, and the Russian drug reference Vidal lists a successor registration in EAEU format dated 31 March 2026 ^[19]. The Russian state register itself is CAPTCHA-gated and was not read directly. The registration is corroborated by converging published sources rather than confirmed at source. That authorization covers the registered Russian medicine, not research-grade material sold for laboratory use.

At least two distinct products share that brand name, and their indication sets differ. One is an over-the-counter lyophilizate for local and external use, indicated narrowly for Candida infections of skin and mucosa ^[19]. The other is a prescription oral lyophilizate carrying broad immunodeficiency and opportunistic-infection indications ^[19]. Vidal files the prescription form under ATC code L03AX, "other immunostimulants", which is a residual bucket rather than a validated pharmacological class ^[19].

No FDA approval and no marketing application appear in openFDA's drug label and Drugs@FDA records ^[18]. Field-qualified queries on substance name, generic name and active ingredient all return no match in those records ^[18]. An EMA medicines search returned no assessment, orphan designation, withdrawal or refusal ^[18]. These records show the absence of any application rather than one that was refused or withdrawn ^[18].

Mechanism, in cells and in mice

Two of the mechanistic studies come from the originating laboratory in Moscow. In vitro, the peptide drove NIH/3T3 mouse fibroblasts toward a differentiated phenotype through ERK1/2 signaling, without engaging SMAD signaling and without requiring CD44 ^[7]. No wound-healing outcome was measured in that work ^[7]. In mice, the peptide attenuated colitis induced by dextran sodium sulfate ^[6]. Bloody diarrhea, weight loss and Il1b, Il6 and Nos2 transcription all fell, as did colon infiltration by Ly6G+ granulocytes and Ly6C+ monocytes ^[6]. That is animal evidence, and it has not been reproduced outside the originating group.

Independent work points the other way. In cell systems, knocking ezrin down inhibited hepatitis C virus infection immediately after entry, while overexpressing ezrin, moesin or radixin did not significantly affect viral replication in a replicon system ^[10]. Losing ezrin function was antiviral there, which is hard to square with supplying an ezrin fragment. That group never tested HEP-1, so this is a contrary mechanistic signal rather than a refutation.

That laboratory's later paper describes HEP-1 as having shown anti-HCV properties in vivo ^[11]. It nonetheless synthesized and screened sixteen radixin peptides in cell culture, and advanced a radixin hinge peptide instead ^[11]. HEP-1 was not carried forward, not used as a positive control and not benchmarked ^[11].

Animal and in vitro antiviral results

Against herpes simplex virus, the originating group reports that the compound possessed no viricidal action ^[15]. The abstract does not scope that statement to any one test system ^[15]. In infected mice it gave 36% protection, with mean survival extended by 1.9 days ^[15]. Protection was greater when exposure preceded infection than when it followed infection, which is the opposite of a therapeutic profile ^[15]. In a street rabies model in mice, protection reached only 30% to 40% ^[16]. That abstract expresses statistical significance as "p < 95-99%", which is not a valid p-value ^[16]. In the originating laboratory's own cell study, the control antiviral interferon alfa-2a protected human SW-13 cells better than the peptide did ^[14].

Two rat studies from an independent Russian group in Kursk placed the Hepon combination behind its comparators ^[12][13]. In alcohol-related acute destructive pancreatitis, the Hepon combination normalized 22.5% of altered erythrocyte membrane parameters and left 35% unchanged, against 50.0% and 12.5% for the comparator combination ^[12]. In chronic ethanol intoxication, the authors concluded that both comparator combinations corrected immune and metabolic disorders more effectively than the Hepon combination ^[13]. Both studies gave combinations, so neither isolates the peptide.

Human research

A 2007 paper on hepatitis C in HIV-positive patients describes two open studies of 18 and 10 patients ^[1]. PubMed indexes it as a Randomized Controlled Trial carrying the MeSH term Double-Blind Method, while the abstract itself names no control arm and no placebo ^[1]. It is the only English-language HEP-1 study PubMed indexes as a Randomized Controlled Trial.

The arithmetic in that abstract does not close. Enrollment is given as 18 and 10, yet the pooled analysis reports 37 patients, and a sentence inside the 10-patient study reads "Three of 15 patients (20%)" ^[1]. The endpoint was viral load measured 30 days after treatment ended, which is not sustained virological response ^[1]. The paper's claim to match peginterferon and ribavirin therapy therefore compares different endpoints across different studies ^[1]. Its journal, Arzneimittelforschung, was renamed Drug Research in 2013, and continues under that title as a MEDLINE-indexed journal ^[18].

The rest of the human record is small and mostly uncontrolled. A second English-language paper reported local use in 25 patients with chronic venous ulcers, with no control group ^[2]. A Russian study of 36 patients with resistant distal ulcerative colitis reported 83.3% clinical and endoscopic improvement, while the same abstract calls the clinical and immunological reaction ambiguous ^[3]. A study of 37 patients after tonsillectomy reported no comparative outcome data at all ^[5]. Its authors nonetheless concluded that local use is justified and can be recommended for wide clinical practice ^[5].

The largest controlled human dataset in this literature enrolled 126 patients with acute purulent soft-tissue infection, 65 against 61 ^[4]. It gave two immunomodulators together, so the peptide's own contribution cannot be separated, and its abstract reports efficacy narratively with no effect size, p-value or confidence interval ^[4]. It is also the one positive clinical report here that lists neither inventor among its authors ^[4].

One independent Western record of a treated patient exists. German virologists described a nine-year-old boy with chronic hepatitis B treated unsuccessfully with interferon, lamivudine and "an obscure drug named Hepon" ^[17]. That group is unconnected to the inventors, and what it records is a failed course ^[17].

Who produced the evidence

Two men, Rupert Holms and Ravshan Ataullakhanov, sit at the center of this literature. Their 2021 review states that the authors are inventors on ezrin peptide patents and have royalty rights ^[8]. It adds that Holms owns shares in Newal R&D Ltd, which owns such patents ^[8]. That review's reference list carries six patent applications, four of them naming both men ^[8]. Much of the literature that review rests on cannot be retrieved or checked ^[8]. Its supporting citations run to untranslated Russian trade journals, conference proceedings, book chapters, a preprint and a source it labels unpublished ^[8].

The same two are among the four authors of the hepatitis C paper ^[1]. Ataullakhanov is senior author on the mouse and cell studies and a co-author on several Russian clinical reports ^[2][5][6][7]. Neither man appears among the authors of the Kursk rat series, which is negative ^[12][13], or of the Massachusetts work, which never tested HEP-1 ^[10][11]. Neither appears on the German case report ^[17] or on the 126-patient surgical study ^[4]. An independent review lists Hepon among interferon inducers developed in former socialist countries and largely unknown in the West, making no efficacy claim about it ^[9].

What the evidence base does not contain

A live PubMed search combining this compound's names with the systematic-review and meta-analysis filters returned zero records ^[18]. No placebo-controlled trial of HEP-1 appears in the indexed literature. The 2007 hepatitis C paper has been cited by four PubMed-indexed papers in nineteen years ^[18]. One of those four is the inventors' own review, and none of the four tested HEP-1 ^[18].

ClinicalTrials.gov holds exactly one registered trial of the peptide, NCT04627233, a Phase 1 randomized, quadruple-masked COVID-19 study with 20 participants estimated ^[18]. Its overall status is unknown, its last known status is not yet recruiting, and it was last updated in November 2020 ^[18]. It has posted no results ^[18].

No pharmacokinetic data for this compound were located. The approved Russian instruction states that pharmacokinetics were not studied, on the grounds of its peptide nature ^[19]. No published half-life, bioavailability or exposure-response figure was located for any route.

The published COVID-19 claims rest on uncontrolled use in a small number of volunteers, described only in the inventors' review ^[8]. That account gives no protocol, no participant count, no control group and no trial registration, and it has no primary publication ^[8]. Its supporting material is a ResearchGate preprint and a source the review itself labels unpublished ^[8]. The volunteer accounts cover HEP-1 and RepG3 together, so nothing in them can be attributed to HEP-1 alone ^[8]. That review concedes the results must be replicated in large randomized placebo-controlled studies to be verified ^[8]. Marketing history is not a substitute for that replication.

Conclusion

HEP-1 is a well-characterized molecule with a settled identity and a real Russian registration ^[18][19]. Its evidence base is nonetheless small, largely uncontrolled and dominated by the people who patented it. The strongest positive work in animals and cells is a mouse colitis study and a fibroblast differentiation study, both from the originating laboratory ^[6][7]. In the two Kursk rat studies, the combination containing it finished behind the comparator combinations ^[12][13]. In the inventors' own cell work, interferon alfa-2a outperformed it ^[14]. Registration and evidence are separate questions here.

Frequently Asked Questions

Is HEP-1 approved for use anywhere? It is registered as a medicine in Russia, where it is marketed under the brand name Gepon ^[19]. That registration is corroborated by the marketing-authorization holder's approved instruction and by Vidal, rather than read from the Russian state register ^[19]. No FDA approval and no marketing application appear in openFDA's drug label and Drugs@FDA records ^[18]. An EMA medicines search returned no assessment, orphan designation, withdrawal or refusal ^[18].

Has the hepatitis C result been independently replicated? No independent replication of it has been published. That 2007 paper has been cited by four PubMed-indexed papers in nineteen years, one of them the inventors' own review, and none of the four tested HEP-1 ^[18]. A live PubMed search of the compound's names with the systematic-review and meta-analysis filters also returned zero records ^[18].

Do Gepon and RepG3 refer to the same peptide? They do not. Gepon is a brand name for the medicine built on HEP-1, sequence TEKKRRETVEREKE ^[18][19]. RepG3 is a separate derivative from the same inventors, sequence GEKKRRETVEREGG, and it returns no PubChem record ^[18].

References

1. 1

   Salamov G, Holms R, Bessler WG, Ataullakhanov R. Treatment of hepatitis C virus infection with human ezrin peptide one (HEP1) in HIV infected patients. Arzneimittelforschung. 2007;57(7):497-504. PMID 17803064. DOI: 10.1055/s-0031-1296637
2. 2

   Kirienko AI, Ataullakhanov RI, Bogachev VIu, Bogdanets LI, Pichugin AV, Zhuravleva OV. Trophic venous ulcers and their relationship with the immune status. Angiol Sosud Khir. 2007;13(1):76-85. PMID 17679977. (indexed as English-language; no DOI in the PubMed record)
3. 3

   Malakhova NS, Pichugin AV, Khalif IL, Ataullakhanov RI. [Use of the Gepon immunomodulator for ulcerative colitis treatment]. Eksp Klin Gastroenterol. 2005;(1):14-9, 106. PMID 15991847. (in Russian)
4. 4

   Chadaev AP, Nurpisov AM. [Experimental and clinical study of immunomodulators Immunomax and Gepon in complex treatment of acute purulent surgical infection]. Antibiot Khimioter. 2004;49(7):9-16. PMID 15690909. (in Russian)
5. 5

   Starosvetskiĭ AB, Pichugina AV, Kazarova AA, Ataullakhanov RI. [Administration of the immunomodulator gepon after tonsillectomy]. Vestn Otorinolaringol. 2005;(3):57-61. PMID 16034352. (in Russian)
6. 6

   Chulkina MM, Pichugin AV, Ataullakhanov RI. Pharmaceutical grade synthetic peptide Thr-Glu-Lys-Lys-Arg-Arg-Glu-Thr-Val-Glu-Arg-Glu-Lys-Glu ameliorates DSS-induced murine colitis by reducing the number and pro-inflammatory activity of colon tissue-infiltrating Ly6G(+) granulocytes and Ly6C(+) monocytes. Peptides. 2020 Oct;132:170364. PMID 32621844. DOI: 10.1016/j.peptides.2020.170364
7. 7

   Chulkina M, Negmadjanov U, Lebedeva E, Pichugin A, Mazurov D, Ataullakhanov R, Holmuhamedov E. Synthetic peptide TEKKRRETVEREKE derived from ezrin induces differentiation of NIH/3T3 fibroblasts. Eur J Pharmacol. 2017 Sep 15;811:249-259. PMID 28668507. DOI: 10.1016/j.ejphar.2017.06.033
8. 8

   Holms RD, Ataullakhanov RI. Ezrin peptide therapy from HIV to COVID: inhibition of inflammation and amplification of adaptive anti-viral immunity. Int J Mol Sci. 2021 Oct 28;22(21):11688. PMID 34769119. PMCID: PMC8584018. DOI: 10.3390/ijms222111688
9. 9

   Silin DS, Lyubomska OV, Ershov FI, Frolov VM, Kutsyna GA. Synthetic and natural immunomodulators acting as interferon inducers. Curr Pharm Des. 2009;15(11):1238-47. PMID 19355963. DOI: 10.2174/138161209787846847
10. 10

    Bukong TN, Kodys K, Szabo G. Human ezrin-moesin-radixin proteins modulate hepatitis C virus infection. Hepatology. 2013 Nov;58(5):1569-79. PMID 23703860. PMCID: PMC3772999. DOI: 10.1002/hep.26500
11. 11

    Bukong TN, Kodys K, Szabo G. A novel human radixin peptide inhibits hepatitis C virus infection at the level of cell entry. Int J Pept Res Ther. 2014 Sep;20(3):269-276. PMID 25379035. PMCID: PMC4217309. DOI: 10.1007/s10989-013-9390-8
12. 12

    Konoplja AI, Litvinova ES, Sunyaykina OA, Bushmina ON, Harchenko AV, Konoplja AA. [Disorders in structural-functional properties of erythrocytes in experimental acute destructive pancreatitis of alcohol etiology and their correction]. Biomed Khim. 2017 Nov;63(6):527-532. PMID 29251614. DOI: 10.18097/PBMC20176306527 (in Russian)
13. 13

    Dolgareva SA, Sorokin AV, Konoplya NA, Bushmina ON, Bystrova NA, Ovod AI. [The use of immunomodulators, antioxidants and hepatoprotectors for the correction of the liver, erythrocites and the immune system disorders in chronic ethanol intoxication]. Biomed Khim. 2018 Aug;64(4):360-367. PMID 30135284. DOI: 10.18097/PBMC20186404360 (in Russian)
14. 14

    Ataullakhanov RI, Holms RD, Katlinskiĭ AV, Deriabin PG, Narovlianskiĭ AN, Mezentseva MV, Ershov FI. [An immunomodulator Hepon inhibits hepatitis C virus replication in human cell cultures in vitro]. Antibiot Khimioter. 2002;47(8):9-11. PMID 12515090. (in Russian; the PubMed title field reads "Ani immunomodulator", an apparent typographical error in the index record)
15. 15

    Barinskiĭ IF, Alimbarova LM, Lazarenko AA, Ataullakhanov RI. [The antiviral activity of peptide immunomodulator "Gepon" in experimental infections caused by herpes simplex viruses types 1 and 2]. Vopr Virusol. 2003 Sep-Oct;48(5):30-3. PMID 14598478. (in Russian)
16. 16

    Gribencha SV, Kholms RD, Ataullakhanov RI, Barinskiĭ IF. [The antiviral activity of the peptide immunomodulator "Gepon" in experimental models of street rabies virus]. Vopr Virusol. 2003 Jul-Aug;48(4):40-4. PMID 12945207. (in Russian)
17. 17

    Schildgen V, Ziegler S, Tillmann RL, Schildgen O. Novel mutation in YMDD motif and direct neighbourhood in a child with chronic HBV-infection and clinical lamivudine and adefovir resistance. Virol J. 2010 Jul 21;7:167. PMID 20646332. PMCID: PMC2914674. DOI: 10.1186/1743-422X-7-167
18. 18

    Database records, retrieved live on 28 August 2026. PubChem PUG-REST: name/174641-44-2 returns CID 25078222, formula C74H132N26O27, molecular weight 1818.0; cid/25078222/xrefs/RN returns 174641-44-2; the names HEP-1 and Gepon both return CID 25078222; RepG3 and GEKKRRETVEREGG return no CID. PubMed E-utilities: esearch "(gepon OR hepon OR ezrin peptide) AND (systematic[sb] OR meta-analysis[pt])" count = 0; esearch "gepon OR hepon" count = 19; elink pubmed_pubmed_citedin for PMID 17803064. returns exactly 34769119, 34529143, 25379035 and 23703860. NLM Catalog efetch: NLM ID 0372660 (Arzneimittelforschung) gives publication start year 1951, publication end year 2012 and volumes indexed to December 2012, with no current indexing status stated; NLM ID 101602406 (Drug Res (Stuttg), Thieme) gives publication start year 2013, no end year, volumes indexed from January 2013, and "Current Indexing Status: Currently indexed for MEDLINE". ClinicalTrials.gov API v2: query "gepon OR hepon OR ezrin peptide" returns one study, NCT04627233, Phase 1, randomized, quadruple masking, estimated enrollment 20, overall status UNKNOWN, last known status NOT_YET_RECRUITING, last update submitted 11 November 2020, hasResults false. openFDA drug/label and drug/drugsfda: field-qualified queries on openfda.substance_name, openfda.generic_name and products.active_ingredients.name all return NOT_FOUND. EMA medicines search returned no assessment, designation, withdrawal or refusal.
19. 19

    Approved Russian product information, retrieved live on 28 August 2026. gepon.ru, the marketing-authorization holder's approved instruction site, gives registration number Р N000015/01, holder OAO Avexima, and a lyophilizate for local and external use with Candida-focused indications. vidal.ru/drugs/hepon gives a 10 mg oral lyophilizate, prescription-only, ATC code L03AX ("other immunostimulants"), registration ЛП-№(014205)-(РГ-RU) dated 31.03.26 with previous registration Р N000015/01, broad immunodeficiency and opportunistic-infection indications, and the statement that pharmacokinetics were not studied owing to the peptide nature of the compound. The Russian State Register of Medicines (grls.rosminzdrav.ru) is CAPTCHA-gated and was not read.