Pain Program

CombinatoRx's CRx-170 is targeted at pain, specifically chronic pain which is defined as pain and disability with episodes lasting more than three months. CRx-170 is an oral synergistic combination drug candidate containing low doses of the steroid prednisolone and the tricyclic anti-depressant nortriptyline.

Chronic pain, affecting millions worldwide, is broken into two categories; nociceptive pain (also called somatic or inflammatory pain) and neuropathic pain. However, chronic pain conditions can have aspects of both of these categories of pain, and there is little consensus on classification of these pain syndromes.

Nociceptive pain results from injury or inflammation of somatic or visceral tissue such as muscoskeletal (rheumatoid arthritis, osteoarthritis, fibromyalgia) or lower back pain. Nociceptive pain is typically described as dull, aching, throbbing pain that is sometimes sharp. Nociceptive pain usually responds to pain medications, anti-inflammatory agents or other drug therapies.

Neuropathic pain is a malfunction of the nervous system due to injury, disease, or trauma such as diabetic neuropathy, postherpetic neuralgia, complex regional pain or HIV-related pain and usually is confined to a small area. Typically, neuropathic pain is described as burning, tingling, shooting, electric-like or lightning-like pain.

In general, chronic pain is less responsive to standard analgesics or pain medications such as opioids. Mixed pain has both inflammatory and neuropathic components and may include muscoskeletal, lower back, cancer-related or complex regional pain.

A Need for Improved Pain Therapies

There is continued need across all chronic pain syndromes for novel agents with improved tolerability, enhanced efficacy, better long-term safety profiles and improved quality of life. This unmet medical need increases as concerns continue to emerge with regard to long-term use of opioid therapy such as potential immune dysfunction, endocrine deficiencies, sleep disorders and hyperalgesia. Tricyclic anti-depressants are widely used to treat various pain syndromes, including chronic lower back pain, with activity across multiple randomized controlled trials, while standard dose steroids are only used intermittently for short periods of time.