Led · Series A · Jul 2024

Spear Bio commercializes the patented Successive Proximity Extension Amplification Reaction (SPEAR) technology, a three-step wash-free workflow that enables measurement of protein biomarkers down to dozens of copies using ubiquitous qPCR instruments. The platform achieves attomolar-level sensitivity from less than 1 microliter of sample — roughly 100 times less sample volume than typical immunoassays — and does not require high-affinity antibodies. The company positions SPEAR as a scalable solution for ultra-sensitive protein measurement aimed at protein research and early disease diagnostics. Spear Bio plans to expand its assay menu and accelerate commercial offerings using the newly raised capital, and is presenting applications to neurology at the Alzheimer’s Association International Conference. The company was founded in 2021 and is headquartered in Woburn, Massachusetts. It recently closed a significant Series A financing that supports its near-term product launch and commercialization activities. Spear Bio, co‑founded in March 2021 as a Harvard Wyss Institute spin‑off, is developing an ultrasensitive immunodiagnostics and proteomics platform called SPEAR (Successive Proximity Extension Amplification Reaction). The SPEAR technology enables detection of single‑digit counts of protein molecules in tiny sample volumes, down to a tenth of a microliter. The company has launched NAB‑Sure™, its first assay and commercial proof‑of‑concept for ultrasensitive quantification of SARS‑CoV‑2 neutralizing antibodies from challenging samples such as finger‑stick dried blood spots and nasal swabs. NAB‑Sure was validated and adopted in major labs during the pandemic, enabling tracking of immunity, vaccine response, and COVID‑19 sero‑surveillance. Spear Bio says it will use the new funding to expand operations and broaden its business reach, and is focused on bringing ultrasensitive immunoassays to market in neurology, immunology, and oncology. The company is based in Woburn, MA.