Auxilium Pharmaceuticals, Inc. / QLT Inc.

Inherited Retinal Diseases (Leber Congenital Amaurosis / Retinitis Pigmentosa)

Disease Overview

Leber Congenital Amaurosis (LCA) and Retinitis Pigmentosa (RP) are inherited retinal dystrophies that cause severe vision loss, often beginning in infancy or childhood. Both conditions involve mutations affecting photoreceptor function, with LCA representing the most severe early-onset form. Treatment options have historically been limited because the genetic heterogeneity (>20 causative genes) and progressive degeneration make pharmacological intervention difficult.

Competitive Landscape

At the time of the proposed Auxilium-QLT merger (June 2014), QLT's lead clinical asset was its synthetic retinoid program (QLT091001), an oral 11-cis-retinal replacement in late-stage development for LCA and RP. The asset competed against an emerging gene therapy field led by Spark Therapeutics' voretigene neparvovec (later Luxturna, approved 2017 for RPE65-mediated retinal dystrophy). Other competing approaches included ProQR's antisense oligonucleotides and ReNeuron's stem cell programs. Visudyne (verteporfin), the photodynamic therapy that QLT had developed with Novartis/CIBA Vision for AMD, had already been divested to Valeant in 2012 and was not part of the Auxilium transaction. The reverse-merger structure (Auxilium shareholders owning 76% of a Canadian-domiciled entity) was tax-driven inversion play rather than a pipeline acquisition; the retinoid asset was a complementary orphan-drug add-on to Auxilium's men's health franchise (Testim, Stendra, Xiaflex). The deal collapsed October 2014 when Endo's superior $2.6B cash-stock bid for Auxilium emerged. QLT received a $28.4M termination fee and subsequently divested the retinoid program.