CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-18). The draft was written by AI, the existence of all 1 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.7.
Verdict No. 2741 · Search date 2026-08-18 · Methodology v0.7

Horse ATG,
does it really help with Improved 6-month hematologic response versus rabbit ATG in severe aplastic anemia?

30-Second Summary
C
Evidence Grade C · 54 · Safety warning
Horse ATG improved hematologic response and a separate survival outcome versus rabbit ATG, but evidence comes from one small active-control trial
Deaths were 4 with horse ATG versus 14 with rabbit ATG. Both products require specialist monitoring for serum sickness, infusion reactions, and severe immunosuppression-related infection.
What the
research shows
The grade is C with 54 points. In a 120-patient NIH randomized trial, 6-month hematologic response was 68% (95% CI 56–80) with horse ATG versus 37% (24–49) with rabbit ATG, an absolute 31-point difference, P<0.001. This exceeded the prespecified 25-point target, but the primary endpoint was blood-count recovery and evidence came from one small active-control trial.
What the
ads claim
It is accurate to say horse ATG improved 6-month hematologic response versus rabbit ATG. It is inaccurate to call survival the primary endpoint or generalize beyond this comparator.
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Useful facts when choosing a product

  • Both ATG products were given with cyclosporine.
  • The primary endpoint was 6-month hematologic response; 3-year survival was separate.
  • Funding was reported from the NIH Intramural Research Program.
Gap Measurement · Verdict 2741 · C 54
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

This prospective NIH single-facility trial randomized 120 patients, 60 per group. It was funded by the NIH Intramural Research Program, with no corporate funding statement. Its two avoidable limitations were total enrollment below 200 and active control without placebo.

02

Why this is classified as C (54)

A publicly funded randomized trial exceeded its prespecified 25-point target, but a surrogate endpoint, single trial, small sample, and active-control-only design give C with 54 points.

Counterpoint. The separate 3-year survival result, 94% versus 70%, remains clinically important even though grading follows the primary endpoint.

Rejudgment record. Cross-check applied — A publicly funded randomized trial exceeded a prespecified 25-point target, but the primary endpoint was blood-count recovery and the study was a small single active-control trial

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (C).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Improved 6-month hematologic responseCRates were 68% versus 37%, an absolute 31-point difference.
Improved 3-year survivalBThe separate endpoint was 94% versus 70%, P=0.008.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Single-facility prospective randomized active-control trial60NIH Intramural Research ProgramHematologic response at 6 months68% (95% CI 56–80) versus 37% (24–49), absolute difference 31 points, P<0.001; separate 3-year survival 94% versus 70%, P=0.008Pivotal single publicly funded trial
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Receipt — 1 References

All 1 cited sources were verified for existence at the original page (as of 2026-08-18).

Scheinberg P, Nunez O, Weinstein B, et al. Horse versus Rabbit Antithymocyte Globulin in Acquired Aplastic Anemia. N Engl J Med. 2011;365:430-438. PMID: 21812672. DOI: 10.1056/NEJMoa1103975. NCT00260689.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-18 · Corrections: none

Cite this verdict

Horse ATG x 6-month hematologic response in severe aplastic anemia Evidence Grade C card
[Chamgap] Horse ATG x 6-month hematologic response in severe aplastic anemia — Evidence Grade C·54. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/horse-versus-rabbit-atg-severe-aplastic-anemia-response/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.