REDWOOD CITY, Calif., Sept. 30, 2013 /PRNewswire/ -- AcelRx Pharmaceuticals, Inc. (Nasdaq: ACRX), a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute and breakthrough pain, today announced that it submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for Zalviso™ (sufentanil sublingual microtablet system). Zalviso is a patient-activated, non-invasive analgesic system, which delivers 15 mcg sufentanil per dose as needed for pain control, subject to a 20 minute lockout period between doses. The proposed indication for Zalviso is the management of moderate-to-severe acute pain in adult patients in the hospital setting. The NDA submission is based primarily on data from a Phase 3 registration program that included two double-blind randomized placebo-controlled clinical trials, one conducted in patients following major abdominal surgery, the other in patients following major joint replacement surgery. Additionally, a Phase 3 open-label active-comparator trial was conducted in patients following either major abdominal or orthopedic surgery, comparing Zalviso to the current standard of care, intravenous patient-controlled analgesia (IV PCA) with morphine. Zalviso successfully achieved the primary efficacy endpoints for each of these studies. Treatment-emergent adverse events were typical of opioid usage post-operatively, were generally mild-to-moderate in nature, and were similar in both active- and placebo-treatment groups for the majority of adverse events. "The Zalviso NDA submission represents a major milestone for AcelRx as we seek FDA approval for our first product candidate based on our proprietary sublingual sufentanil formulation and our delivery system technology," stated Richard King, president and CEO of AcelRx. "Based on the results of our clinical trials, we believe Zalviso has demonstrated an ability to achieve rapid onset of pain relief, thereby enabling patients to manage their moderate-to-severe acute pain effectively over 48 to 72 hours post-surgery. If approved by the FDA, Zalviso could provide hospitals and patients with an attractive alternative to the current standard of care, specifically IV PCA-delivered opioids." The NDA submission required payment to the FDA of a $1.95 million NDA filing fee in the third quarter of 2013, which will be included in the Company's income statement as an additional research and development expense. FDA regulations allow for the waiver of the NDA filing fee if the Company is filing its first NDA and qualifies as a small business with less than 500 employees. The FDA requested the Small Business Administration (SBA) to determine if AcelRx was a small business, and the SBA recently ruled that AcelRx could not qualify as a small business. Previously Reported Phase 3 Clinical Trial Results for Zalviso The 505(b)(2) NDA submission for Zalviso is based on a comprehensive development program and includes data from AcelRx's three Phase 3 clinical trials. As previously reported, Zalviso met the FDA-agreed primary endpoints in the two double-blind, placebo-controlled Phase 3 registration studies conducted in patients who had undergone major open-abdominal surgery or orthopedic surgery that involved either knee or hip replacement procedures. In each of these trials, patients treated with Zalviso to manage their post-surgical pain reported a greater sum of the pain intensity difference to baseline over 48 hours (SPID-48) compared to placebo-treated patients (p=0.001 and p<0.001, respectively). Adverse events considered possibly or probably related to treatment were generally mild-to-moderate in nature and similar for the majority of adverse events between Zalviso- and placebo-treated patients, with the exception of itching, which was significantly greater (p < 0.05) in the Zalviso-treated group.