RXi Pharmaceuticals Inc. is a US biotechnology company focused on the field of siRNA. The company's name was changed to Phios Pharmaceuticals in 2018. The company is using its siRNA platform to develop a pipeline of dermatology and ophthalmology therapeutics. The company has developed self-delivering RNAi compounds for the treatment of dermal and retinal scarring and is also working on a proprietary topical formulation of diphenylcyclopropenone for the treatment of warts, alopecia areata and cutaneous metastases of melanoma.
Background
RXi Pharmaceuticals in its first incarnation was founded in late 2006 by the Los Angeles-based drug development company CytRx and four scientific founders including Craig Mello, who had recently received the 2006 Nobel Prize in Physiology or Medicine for his co-discovery of RNAi. The company was taken public in March 2008 when RXi Pharmaceuticals was spun out of CytRx as a separate company. In 2011 RXi Pharmaceuticals acquired Apthera, developer of a peptide vaccine called NeuVax, and changed its name to Galena Biopharma to reflect its change of focus. Galena Biopharma made the decision to spin out the siRNA programs into a separate company, again to be called RXi Pharmaceuticals. This second incarnation of RXi Pharmaceuticals was completed in 2012 when its stock started trading publicly. RXi Pharmaceuticals stock is traded on Nasdaq under the code RXII. The stock initially traded OTC on 10 May 2012 after the spin-out from Galena Biopharma. It upgraded to OTCQX on 19 June 2013 and to Nasdaq on 11 February 2014. The firm is headquartered in Marlborough, Ma. in Middlesex County. The firm's Chairman is Robert Bitterman, previously an executive at Aventis. Its CEO is Dr Geert Cauwenbergh, previously a Johnson & Johnson executive who was named CEO in May 2012. Craig Mello remains involved with RXi as Chairman of its Scientific Advisory Board.
Products
RXi's technology platform allows the development of 'self-delivering’ RNAi compounds, or 'sd-rxRNA' for short, in which drug-like properties were built into the RNAi compound itself, rather than relying on liposomal delivery to improve circulation time and cellular uptake. This platform was developed through systematic medicinal chemistry screening. RXi scientists have shown the utility of their platform in three papers: RXi's SD-rxRNA compounds are constructed using a single-stranded phosphorothioate region, a short duplex region, and a variety of nuclease-stabilizing and lipophilic chemical modifications. The result is spontaneous uptake in multiple cell typesin vitro and in vivo. Samcyprone is RXi's proprietary topical formulation of diphenylcyclopropenone. The product, an immunomodulator that works by initiating a T-cell response, entered Phase II for the treatment of cutaneous warts in December 2015. In March 2015 it was granted Orphan Drug Designation by the US Food and Drug Administration for the treatment of malignant melanoma stage IIb to IV. RXi's first sd-rxRNA candidate, RXI‑109, is designed to reduce the expression of connective tissue growth factor, a critical regulator of biological pathways involved in fibrosis, including scar formation in the skin. The product has been in several clinical studies, including: Abdominoplasty Phase I study,., initiated in June 2012, looked at the ability of RXI 109 to reduce scarring in women undergoing elective abdominoplasty; and Neovascular Age-related Macular Degeneration Phase 1/2 study. initiated in November 2015.
