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SuspendedNCT04210141ODADSUpdated Apr 1, 2024

Optimal Dose of Antivenom for Daboia Siamensis Envenomings

A Phase 2 interventional study of lyophilized BPI viper antivenom in Daboia Siamensis Envenoming, sponsored by Myanmar Oxford Clinical Research Unit. Suspended at 1 site in Myanmar. Open to participants aged 16 Years and older. Per ClinicalTrials.gov, last updated 2024-04-01.

Sponsored by Myanmar Oxford Clinical Research Unit · Phase 2, Interventional, and Treatment

Why this study was suspended
due to current political circumstances in study site area.
Phase
Phase 2
Study type
Interventional
Enrollment
200
Allocation
Randomized
Ages
16 Years and older
Sex
All
01

Study summary

The aim of the study is to identify an 'optimal' initial dosing of the new Burma Pharmaceutical Industry (BPI) lyophilized mono-specific antivenom for patients with systemic Daboia siamensis envenoming. The initial dosing will aim to reverse venom-induced coagulopathy (as demonstrated by a negative 20 minutes Whole Blood Clotting Time (20WBCT) at 6 hours in 95% of patients whilst causing less than 5% anaphylactic reaction.

Read the detailed description

Snake-bite envenoming (SBE) was re-categorized as a priority neglected tropical disease by the World Health Organization (WHO) in 2017. Antivenom is considered to be one of the most cost effective health interventions. Despite this, due to challenges in manufacture, reliance on cold chain for transport and storage, and geographically remote location of most envenomed patients, many patients do not receive the antivenom they require in a timely manner. The WHO strategy for a globally coordinated response to SBE highlighted the need to prioritize clinical research into the safety and effectiveness of antivenoms.

Myanmar is a country with a high incidence of snake-bite with an estimated 25,000 snake-bites and 1250 deaths per year. Daboia siamensis (Eastern Russell's viper) is responsible for 85% of snake-bites presenting to hospitals in Myanmar. Given their natural habitat and abundance of prey within the paddy fields, envenoming predominantly occurs in rural areas affecting agricultural workers.

Following a recent 4-year collaborative initiative between institutions in Myanmar and Australia entitled the Myanmar Snakebite project, antivenom production facilities have improved resulting in the production of a new monospecific lyophilized F(ab)'2 antivenom (Viper antivenom BPI). The new lyophilized antivenom has replaced the former liquid antivenom and has been distributed countrywide. The current dosing strategy is based on unpublished results of pre-clinical testing and stratified into two doses according to absence or presence of clinical features of severity at presentation (80 mL and 160 mL, respectively). No clinical trial data or post marketing data has been published to support the efficacy or toxicity of these recommended doses. This lack of robust clinical evidence to support dosing of antivenom is mirrored across the world with few well conducted trials to determine the safety and efficacy of antivenoms.

This paper presents a novel phase 2, model based, Bayesian adaptive design to determine optimal antivenom dosing for Russell's viper envenoming. In this context there are two concurrent considerations for dose optimality. Firstly, the efficacy of the dose, defined in this context as restoration of blood coagulation within 6 hours; secondly, the dose-related toxicity, defined as the occurrence of an anaphylactic reaction within 180 minutes post antivenom administration. The model based design estimates dose-response curves for both the efficacy outcome and the toxicity outcome, and thus derives a user-defined 'optimal dose'. Patients will be randomized at a ratio of 4:1 to either adaptive dose or standard of care respectively.

The study team will perform a number of nested studies within the dose finding trial:

  • An assessment of the pharmacokinetic properties of Daboia siamensis venom pre and post antivenom administration.
  • A parallel observation study of severely envenomed patients who will be administered 160mL (current standard of care).
  • Sensitivity and specificity analysis of the 20WBCT and point of care International Normalized Ratio at detecting coagulopathy.
  • A prospective follow up of envenomed patients to define the envenoming sequelae of Daboia siamensis envenoming.
  • An assessment of ferryl-haem derivatives in urine of envenomed patients.
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Conditions studied

  • Daboia Siamensis Envenoming
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In context

Lead sponsor

Myanmar Oxford Clinical Research Unit is the lead sponsor of 6 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
16 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Patients suspected of systemic envenoming with DS
  2. Incoagulable blood by 20-minute WBCT
  3. Antivenom naïve
  4. Age ≥ 15

Exclusion criteria

Exclusion Criteria:

  1. Receiving anticoagulant therapy e.g. warfarin
  2. Known bleeding disorder e.g. haemophilia
  3. Decompensated liver disease
  4. Severely envenomed patients (as defined in the Myanmar National Guidelines)
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Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
200 participants (estimated)

Study arms

  • Active comparator
    Standard of care

    Patients will receive an initial antivenom dose of 80mL lyophilized BPI viper antivenom, as per current national guidelines

    Biological: lyophilized BPI viper antivenom

  • Experimental
    Adaptive arm

    Patients will receive an initial dose of lyophilized BPI viper antivenom determined by the adaptive model.

    Biological: lyophilized BPI viper antivenom

Interventions

  • Biologicallyophilized BPI viper antivenom

    Antivenom

06

What researchers measure

Primary outcomes

  1. Blood Coagulation

    Blood coagulation at 6 hours as measured by the 20 minute WBCT (binary outcome)

    Time frame: within 24 hours of patient recruitment

  2. Anaphylaxis

    Anaphylaxis as defined by the European Academy of Allergy and Immunology within 180 minutes of antivenom administration

    Time frame: within 24 hours of patient recruitment

Secondary outcomes

  1. Time to restoration of blood coagulability as determined by the 20 WBCT.

    Time frame: within 24 hours of patient recruitment

  2. International normalized ratio (INR) determined by the POC INR meter.

    Time frame: within 24 hours of patient recruitment

  3. Blood coagulability as determined by PT and fibrinogen

    Time frame: within 24 hours of patient recruitment

  4. Occurrence of any serious adverse events

    Time frame: within 24 hours of patient recruitment

  5. The occurrence of envenoming sequelae at 3 month follow up

    Time frame: within 6 months of patient recruitment

  6. The occurrence of detectable ferryl-haem derivatives in urine samples

    Time frame: within 6 months of patient recruitment

  7. The occurrence of Capillary Leak Syndrome

    Time frame: within 2 weeks of patient recruitment

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Study locations

1 site
  • Myanmar Oxford Clinical Research Unit
    Yangon, Myanmar
08

References and documents

Publications

  • Gutierrez JM, Calvete JJ, Habib AG, Harrison RA, Williams DJ, Warrell DA. Snakebite envenoming. Nat Rev Dis Primers. 2017 Sep 14;3:17063. doi: 10.1038/nrdp.2017.63. Erratum In: Nat Rev Dis Primers. 2017 Oct 05;3:17079. doi: 10.1038/nrdp.2017.79. PubMed 28905944 ↗
  • Williams DJ, Faiz MA, Abela-Ridder B, Ainsworth S, Bulfone TC, Nickerson AD, Habib AG, Junghanss T, Fan HW, Turner M, Harrison RA, Warrell DA. Strategy for a globally coordinated response to a priority neglected tropical disease: Snakebite envenoming. PLoS Negl Trop Dis. 2019 Feb 21;13(2):e0007059. doi: 10.1371/journal.pntd.0007059. eCollection 2019 Feb. No abstract available. PubMed 30789906 ↗
  • Myint-Lwin, Warrell DA, Phillips RE, Tin-Nu-Swe, Tun-Pe, Maung-Maung-Lay. Bites by Russell's viper (Vipera russelli siamensis) in Burma: haemostatic, vascular, and renal disturbances and response to treatment. Lancet. 1985 Dec 7;2(8467):1259-64. doi: 10.1016/s0140-6736(85)91550-8. PubMed 2866333 ↗
  • Alfred S, Bates D, White J, Mahmood MA, Warrell DA, Thwin KT, Thein MM, Sint San SS, Myint YL, Swe HK, Kyaw KM, Zaw A, Peh CA. Acute Kidney Injury Following Eastern Russell's Viper (Daboia siamensis) Snakebite in Myanmar. Kidney Int Rep. 2019 May 29;4(9):1337-1341. doi: 10.1016/j.ekir.2019.05.017. eCollection 2019 Sep. No abstract available. PubMed 31517153 ↗
  • Wheeler GM, Mander AP, Bedding A, Brock K, Cornelius V, Grieve AP, Jaki T, Love SB, Odondi L, Weir CJ, Yap C, Bond SJ. How to design a dose-finding study using the continual reassessment method. BMC Med Res Methodol. 2019 Jan 18;19(1):18. doi: 10.1186/s12874-018-0638-z. PubMed 30658575 ↗

Individual participant data

Plan to share: Undecided — For ethics purposes, there is no current plans to share IPD with other researchers.

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 1, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT04210141
Lead sponsor
Myanmar Oxford Clinical Research Unit
Collaborators
University of Oxford, Mahidol Oxford Tropical Medicine Research Unit
Responsible party
Sponsor
First posted
Dec 24, 2019
Start date
Apr 2025 (estimated)
Primary completion
Feb 1, 2027 (estimated)
Completion
Nov 1, 2027 (estimated)
Last update
Apr 1, 2024

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is suspended, as verified in Oct 2023. You cannot join it, but the record below documents what was studied.

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