Rib-X Pharmaceuticals, a US-based antibiotics developer backed by drugs companies GlaxoSmithKline (GSK) and AstraZeneca’s corporate venturing units, has raised $18.7m in the first tranche of a planned $67.5m series two preferred stock financing.
Vatera Healthcare Partners, a a venture capital firm established by Michael Jaharis, founder of Kos Pharmaceuticals, a specialty pharmaceutical company sold to Abbott Laboratories in 2006 for $4.2bn, and of Key Pharmaceuticals, a specialty pharmaceutical company merged with Schering-Plough in 1986 for $836m, led the round as a new investor, and was joined by return backers, private equity firms Warburg Pincus, ABS Ventures and Vox Equity Partners.
Rib-X plans to use the proceeds to initiate the phase three clinical programme for Delafloxacin for the treatment of acute bacterial skin and skin structure infections.
In May, Rib-X postponed its $80m initial public offering, according to Nasdaq OMX.
Shareholders in Rib-X at that time included SR One, the corporate venturing unit belonging to GSK , which holds 7.5% of Rib-X’s common stock, and MedImmune Ventures, a corporate venture fund operated by pharmaceuticals company AstraZeneca (which holds 6%).
Also holding stock in Rib-X are private equity (PE) firm Warburg Pincus (45%), and venture capital (VC) firms Saints Capital (23.1%), Oxford Biosciences Partners (13.9%) and Cardinal Partners (5.4%).
Additional investors include VC firm ABS Ventures, VC fund Euclid SR (also backed by GSK) and PE firm Vox Equity Partners. Rib-X had raised about $160m since 2002.