ParcelBio develops an APEXm (Amplified and Prolonged EXpression mRNA) platform that uses novel RNA domains to enhance protein expression and extend activity for mRNA medicines. Its lead program is an in vivo CAR-T therapy targeting pathogenic B cells aimed at achieving deep B-cell depletion for durable, drug-free remission in autoimmune disease. The company is also advancing programs in oncology and encoded protein therapeutics. ParcelBio emphasizes enabling sustained CAR expression without viral delivery or ex vivo manufacturing to create scalable, off-the-shelf therapies. The company is led by cofounders David Weinberg (CEO) and Chris Carlson (CSO) and is based in San Francisco. ParcelBio announced a $13M Seed round to fund further development of its platform and pipeline.

Total raised

$13M

Funding rounds

1

Latest round

Seed

Latest activity

May 2026