Emtora Biosciences

Commercializing eRapa™,
a novel, targeted formulation of rapamycin

What is eRapa™


Rapamycin is a naturally occurring chemical first discovered in the soil on Easter Island (Rapa Nui) in the early 1970s.  Rapamycin and its rapalogues are indicated for use in advanced stage cancer and anti-organ rejection therapies.  Though rapamycin has demonstrated efficacy in multiple indications from cognition to cancer prevention, its low bio-availability, significant toxicity, and large interpatient pharmacokinetic variation (up to 8x) have limited its market potential.

eRapa™ was developed to improve rapamycin's pharmacokinetics.  It is a a proprietary, patented, micro-encapsulated formulation of rapamycin that protects the active ingredient from rapid, low pH degradation in the stomach. The eRapa (encapsulated rapamycin) drug product consists of sub-micron rapamycin particles incorporated into poly (methyl methacrylate) polymer (Eudragit® L 100 / S 100).  

eRapa™ has composition of matter and manufacturing patent protection through 2035.



Benefits of eRapa™ over rapamycin and current rapalogues include:

  • Enhanced bioavailability improves drug absorption, allows for a lower therapeutically effective dose, and improves its toxicity profile.  eRapa™ consistently provides approximately 30% more drug than generic rapamycin (Emtora Biosciences unpublished data);
  • Less interpatient pharmacokinetic variation reduces need for therapeutic drug monitoring and limits adverse events;
  • Targeted delivery to the duodenum, lower intestine and colon delivers the active ingredient directly to the site of active disease in GI indications. eRapa has a systemic effect and a local (GI) effect.


Mechanism of Action

eRapa™ modulates the mTOR pathway, which controls cell growth, proliferation, nutrient transport, autophagy, and survival.  Chronic, intermittent, low dose eRapa™:

  • Rejuvenates the immune system;
  • Suppresses cancer in cancer-prone animals and prolongs health span and life span
  • Enhances immature and naïve populations of lymphocytes;
  • Decreases populations of accumulated (age) or induced (cancer) PD-1 expressing (exhausted) T cells.