PF-610355
PF-610355 is an inhalable ultra-long-acting β2 adrenoreceptor agonist that was investigated as a treatment of asthma and Chronic obstructive [pulmonary disease|COPD] by Pfizer. It utilizes a sulfonamide agonist headgroup, that confers high levels of intrinsic crystallinity that could relate to the acidic sulfonamide motif supporting a zwitterionic form in the solid state. Optimization of pharmacokinetic properties minimized systemic exposure following inhalation and reduced systemically mediated adverse events. Its in vivo duration on action confirmed its potential for once-daily use in humans.
The investigation and development of PF-610355 were discontinued in 2011, likely for strategic and regulatory reasons.