Abstract: The present invention relates to certain biphenyl sulfonamide derivatives of Formula (Ia) and pharmaceutical compositions thereof that modulate the activity of the histamine H3-receptor. Compounds of the present invention and pharmaceutical compositions thereof are directed to methods useful in the treatment of histamine H3-associated disorders, such as, cognitive disorders, epilepsy, brain trauma, depression, obesity, disorders of sleep and wakefulness such as narcolepsy, shift-work syndrome, drowsiness as a side effect from a medication, maintenance of vigilance to aid in completion of tasks and the like, cataplexy, hypersomnia, somnolence syndrome, jet lag, sleep apnea and the like, attention deficit hyperactivity disorder (ADHD), schizophrenia, allergies, allergic responses in the upper airway, allergic rhinitis, nasal congestion, dementia, Alzheimer's disease and the like.