[4] Mondobiotech began research into Vasoactive intestinal peptide (VIP), a naturally occurring substance in humans that was first identified in the 1970s.

[7][8] In September 2020, Relief partnered with US-Israeli firm NRX Pharmaceuticals (formerly NeuroRx Inc) for the co-development of the drug and the co-ordination of US trials.

[11][12] On 7 October 2021 Relief Therapeutics filed a lawsuit against NRX Pharmaceuticals and its CEO Dr. Jonathan Javitt in the Supreme Court of the State of New York,[13] citing multiple alleged breaches of the collaboration agreement signed by the two companies for the co-development of aviptadil.

[15] On 29 November 2021, NRX announced that data analysis from the NIH-sponsored Phase 3 trial showed a fourfold increase in survival at 60 days for patients administered with Zyesami (Aviptadil) vs those who received placebo.

[18] In September 2021, APR launched a chewable tablet for the treatment of Phenylketonuria, called PKU GOLIKE KRUNCH, in Germany and Italy.