Regulatory Affairs

Soligenix gets orphan drug designation from European Commission for RiVax to prevent Ricin poisoning

Published 26 March 2018

The European Commission has granted orphan drug designation to the Soligenix recombinant modified ricin toxin A-chain subunit (the active pharmaceutical ingredient in RiVax) for the prevention of ricin poisoning.

RiVax has previously been granted orphan drug designation from the US Food and Drug Administration (FDA).

The European Commission grants orphan designations for medicines that treat a life-threatening or chronically debilitating condition affecting no more than five in 10,000 persons in the European Union (EU) and where no satisfactory treatment is available. 

In addition to a 10-year period of marketing exclusivity in the EU after product approval, orphan drug designation provides incentives for companies seeking protocol assistance from the EMA during the product development phase, and direct access to the centralized authorization procedure which allows access to all 28 EU member states’ markets.

Soligenix president and CEO Christopher Schaber said: “We are extremely pleased to have received European orphan drug designation for the RiVax program.

“This EU orphan designation, combined with our US orphan designation, positions this biodefense program for a potentially accelerated global regulatory product development pathway to address this unmet need. 

“RiVax® has shown up to 100% protection against aerosolized ricin exposure in non-human primates and safety in humans and we look forward to further developing our thermostable formulation for human use.”

Ricin toxin is a lethal plant-derived toxin and potential biological weapon because of its stability and high potency, and the fact it is readily extracted from by-products of castor oil production.  Ricin comes in many forms including powder, mist or pellet.  Ricin can also be dissolved in water and other liquids. 

The US Centers for Disease Control and Prevention estimates that the lethal dose in humans is about the size of a grain of salt. 

Ricin toxin illness causes tissue necrosis and general organ failure leading to death within several days of exposure.  Ricin is especially toxic when inhaled.  Ricin works by entering cells of the body and preventing the cells from making the proteins it needs.  Without the proteins, cells die, which is eventually harmful to the entire body.

RiVax is Soligenix’s proprietary heat stable recombinant subunit vaccine developed to protect against exposure to ricin toxin.  With RiVax, Soligenix is a world leader in the area of ricin toxin vaccine research.

RiVax contains a genetically altered version of a ricin toxin A-chain containing two mutations that inactivate the toxicity of the ricin molecule.  A Phase 1A clinical trial was conducted with a formulation of RiVax® that did not contain an adjuvant. 

This trial revealed dose dependent seroconversion as well as lack of toxicity of the molecule when administered intramuscularly to human volunteers.  The adjuvant-free formulation of RiVaX induced toxin neutralizing antibodies that lasted up to 127 days after the third vaccination in several individuals.

Source: Company Press Release