Evidence map›Paper›PMID 34285621›Full record

ArticleJournal of blood medicine2021

Efficacy of rFIXFc versus rIX-FP for the Treatment of Patients with Hemophilia B: Matching-Adjusted Indirect Comparison of B-LONG and PROLONG-9FP Trials.

Jan Astermark, Piotr Wojciechowski, Samuel Aballéa, Zalmai Hakimi, Jameel Nazir, Robert Klamroth

Open access · goldAbstract read
In one paragraph

Article in Journal of blood medicine, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed
1.0field-weighted citation impact, top 24% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

7 citing papers in PubMed, 7 citations in OpenAlex.

  1. Trial
  2. Extended Half-Life Factor Concentrates in Haemophilia Treatment.Transfusion medicine and hemotherapy : offizielles Organ der Deutschen Gesellschaft fur Transfusionsmedizin und Immunhamatologie · 2026
    Review
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 4 institutions in 3 countries.

Jan AstermarkDepartment of Translational Medicine, Lund University, and Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden.
Piotr WojciechowskiCreativ-Ceutical, Krakow, Poland.ORCID 0000-0001-8400-1171
Samuel AballéaCreativ-Ceutical, Rotterdam, the Netherlands.
Zalmai HakimiSwedish Orphan Biovitrum AB, Stockholm, Sweden.
Jameel NazirSwedish Orphan Biovitrum AB, Stockholm, Sweden.
Robert KlamrothDepartment of Internal Medicine, Hemophilia Treatment Centre, Vivantes Klinikum im Friedrichshain, Berlin, Germany.ORCID 0000-0003-4194-8183
Swedish Orphan Biovitrum (Sweden) · SECreativ-Ceutical (France) · FRKlinikum im Friedrichshain · DELund University · SE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeIn patients with hemophilia B, treatment with extended half-life (EHL) recombinant factor IX allows for longer dosing intervals while providing equal or superior bleeding protection compared with standard half-life products. This enables flexible, individualized treatment schedules, which reduce the burden of prophylaxis and improve patient outcomes. This analysis compared the efficacy of recombinant factor IX Fc fusion protein (rFIXFc) and recombinant factor IX albumin fusion protein (rIX-FP), two EHL therapies approved for prophylaxis and treatment of bleeding in hemophilia B. PATIENTS AND

methodsMatching-adjusted indirect treatment comparison (MAIC) was used to adjust the between-treatment differences in baseline characteristics. Individual patient data for rFIXFc (B-LONG) were matched to aggregated data for rIX-FP (PROLONG-9FP) followed by statistical comparison for estimated annualized bleeding rate (ABR) using a Poisson regression model with adjustment for over dispersion. Data were analyzed according to treatment regimen prior to study entry: prior prophylaxis (rFIXFc, n=48; rIX-FP, n=40) or prior episodic treatment (n=43 and n=19, respectively). Relative treatment effects are presented as incidence rate ratios (IRR) with 95% confidence intervals (CI).

resultsAfter adjustment for baseline characteristics, estimated ABR observed for rFIXFc and rIX-FP was not significantly different in patients on prior prophylaxis (1.87 versus 1.58; IRR 1.18, 95% CI 0.67-2.10) or prior episodic (2.25 versus 2.22; IRR 1.01 95% CI 0.40-2.57) regimens.

conclusionThis MAIC analysis shows that the estimated ABR for rFIXFc-treated patients from B-LONG was similar to that of rIX-FP-treated patients from PROLONG-9FP and, therefore, indicates that the two EHL therapies provide similar efficacy when used as prophylaxis for patients with hemophilia B. Trough levels differ between the two products (1-3% [targeted] versus 20% [observed], respectively), suggesting that trough level is not a surrogate indicator when ABR is used as a criterion for clinical efficacy when comparing these FIX products in hemophilia B.

Indexed as

annualized bleeding ratecomparative effectiveness researchfactor IX deficiencyfactor IX Fc fusion proteinrIX-FP fusion proteintreatment outcome

Identifiers

PMID34285621
PMCPMC8286734
OpenAlexW3178827065

What OpenQuestion holds

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LicenceCC BY-NC
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.