The FDA granted 510(k) clearance on June 18 to Diazyme Laboratories for its Lipoprotein(a) Molarity Assay, making the San Diego company the second diagnostic manufacturer to win U.S. clearance for an Lp(a) test that reports in nanomoles per liter (nmol/L). Roche was first, receiving 510(k) clearance for its Tina-quant Lp(a) Gen.2 Molarity assay in late January 2025.
The distinction between mass units and molar units is not bureaucratic. Lp(a) particles vary substantially in size because of a polymorphic protein called apolipoprotein(a), whose isoform diversity can cause measured Lp(a) mass to differ by up to 200 percent between two patients with identical molar — and therefore identical cardiovascular — risk. The European Society of Cardiology has endorsed nmol/L as the preferred reporting unit precisely to neutralize that variability. Diazyme’s assay uses an isoform-independent method, so results should hold across the genetic diversity labs actually encounter.
The clinical stakes are rising fast. An estimated one in five people globally carries elevated Lp(a), a genetically determined risk factor for atherosclerotic cardiovascular disease that no approved drug yet specifically targets. That is about to change: Novartis’s pelacarsen is in the Lp(a)HORIZON outcomes trial, and Amgen’s olpasiran anchors the OCEAN(a) Phase 3 study, which enrolled patients at a threshold of ≥200 nmol/L. Both trials use molar endpoints, creating a near-term need for labs to run companion diagnostics in compatible units.
The 510(k) pathway authorizes Diazyme’s device through substantial equivalence to a legally marketed predicate — it is a clearance, not a PMA approval. For hospital and reference labs still running older mass-unit platforms, the Diazyme clearance opens a second vendor option as they upgrade cardiovascular risk panels ahead of what could be a busy regulatory period for Lp(a)-lowering therapies.