A review of the two major regulatory pathways for non-proprietary low-molecular-weight heparins
Bibliographic record
Abstract
With the expiry or pending expiry of originator low-molecular-weight heparin (LMWH) patents, pharmaceutical companies have invested in developing non-proprietary versions of LMWHs. LMWHs are manufactured by depolymerising highly purified unfractionated heparin. In contrast to traditional synthetic drugs with well-defined chemical structures, LMWHs contain complex oligosaccharide mixtures and the different manufacturing processes for LMWHs add to the heterogeneity in their physicochemical properties such that the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) consider existing originator LMWHs to be distinct medicinal entities that are not clinically interchangeable. The FDA views LMWHs as drugs and has approved two non-proprietary (generic) LMWHs, using the Abbreviated New Drug Application pathway. In contrast, the World Health Organization and the EMA view LMWHs as biological medicines. Therefore, the EMA and also the Scientific and Standardization Subcommittee on Anticoagulation of the International Society on Thrombosis and Haemostasis and the South Asian Society of Atherosclerosis and Thrombosis have all published specific guidelines for assessing non-proprietary (biosimilar) LMWHs. This manuscript reviews why there are two distinct pathways for approving non-proprietary LMWHs. Available literature on non-proprietary LMWHs approved in some jurisdictions is also reviewed in order to assess whether they satisfy the requirements for LMWHs in the three guidance documents. The review also highlights some of the significant difficulties the two pathways pose for manufacturers and an urgent need to develop a consensus governing the manufacture and regulation of non-proprietary LMWHs to make them more widely available.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.004 | 0.004 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.006 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".