Is sensory processing disorder on the autism spectrum? is there a cure?

Definitely: Spd is a neurological disorder causing difficulties with taking in, processing & responding to sensory information about the environment & from within his own body(visual, auditory, tactile, olfaction, gustatory, vestibular &propioception). There is no known cure but there are many treatments available. Dr. Lucy miller is a very good resource.

Partially: Unfortunately, sensory processing disorder is not fully recognized or embraced by all in medical and behavioral and therapy fields. Sensory defensiveness or hyper-reactivity to various stimuli, can be seen in autism, but also in anxiety, depression, mental retardation, adhd of any type and other situations. Many therapies are available, they help some, not all. I'd be wary of any cure claim.