ARX-04 is a non-invasive, fast-onset sufentanil product candidate for treatment of patients with moderate-to-severe acute pain, both on the battlefield and in civilian settings of trauma or injury. In situations of trauma or injury, it is advantageous to have a rapid-acting, non-invasive method of treating acute pain. In the battlefield, in the emergency room and in ambulatory care environments, patients often do not have immediate intravenous, or IV, access available. Intramuscular injections are the current standard of care on the battlefield, but they are invasive, painful, and present an increased risk of infection to both patient and health care professional. In addition, in cases of severe trauma where the patient is often in hypovolemic shock and muscles are not well perfused, pain medication given by intramuscular injection may not readily reach the blood stream to provide pain relief, rendering this route of delivery suboptimal. Oral pills and liquids generally have slow and erratic onset of analgesia. Even patients with IV access may have undesirable side effects with the commonly used IV opioids morphine and hydromorphone, such as sedation or oxygen desaturation. Moreover, IV dosing results in high peak plasma levels, thereby limiting the opioid dose and requiring frequent redosing intervals to titrate to satisfactory analgesia. Additional treatment options are needed which can safely and rapidly treat acute pain, in both civilian and military settings.

ARX-04 is a product candidate in development for the treatment of moderate-to-severe acute pain, consisting of sufentanil, a high therapeutic index opioid, in AcelRx's proprietary NanoTab technology that enables rapid sublingual absorption when the NanoTab is placed under the tongue. As a result, sufentanil NanoTabs can provide rapid onset of analgesia in a non-invasive method of administration and display a consistent pharmacokinetic profile due to a high percentage of drug being absorbed sublingually instead of through the gastrointestinal tract. In the Phase 2 study of ARX-04 currently underway, two different doses, 20 mcg and 30 mcg of sufentanil will be evaluated in patients experiencing moderate-to-severe acute pain, in order to determine an appropriate dose to advance into Phase 3. We believe ARX-04 may ultimately be proven beneficial in a variety of medically supervised settings, including use in battlefield casualty treatment, by paramedics during patient transport, in the emergency room, for non-surgical patients experiencing pain in the hospital, or for post-operative patients, following either short-stay or ambulatory surgery, who do not require more long-term patient-controlled analgesia (PCA). According to the Centers for Disease Control and Prevention (CDC) data, there are more than 45 million injury-related emergency department visits and 43 million ambulatory surgery procedures annually in the United States.

Development Status

We are currently conducting a Phase 2, placebo-controlled, dose-finding study of its ARX-04 sufentanil NanoTab product candidate. This study will enroll approximately 100 patients following bunionectomy surgery, randomized into one of three groups; 20 mcg sufentanil NanoTab, 30 mcg sufentanil NanoTab or placebo, administered by healthcare personnel, as needed every hour. The study will evaluate the ability of sufentanil NanoTabs to manage moderate-to-severe acute pain over the first 12 hours following bunionectomy, and correlate the pain response with sufentanil pharmacokinetics. AcelRx is conducting this study with funding provided by a grant from the U.S. Army Medical Research and Materiel Command, or USAMRMC.

ARX-04 Publications and Press Releases

AcelRx Pharmaceuticals Doses the First Patients in ARX-04 Phase 2 Clinical Study

Press release

AcelRx Announces $5.6 Million Department of Defense Grant to Develop ARX-04, a New Acute Pain Product Candidate

Press release