CAMBRIDGE, England, January 5, 2016 /PRNewswire/ --
Acacia Pharma Group plc ("Acacia Pharma"), the supportive care company developing products for US and international markets, announces positive results from a Phase 3 study investigating BAREMSIS™ (amisulpride injection, formerly APD421) in combination with standard antiemetics for the prevention of post-operative nausea & vomiting ("PONV") in high-risk patients.
Dr Julian Gilbert, Acacia Pharma's CEO commented: "There is a compelling medical and commercial need for a safe and effective dopamine antagonist antiemetic that can be used in combination with current standard-of-care to manage PONV. The results from this study show that BAREMSIS could be used in the prevention of PONV in high-risk patients. Very pleasingly, the magnitude of BAREMSIS' effect, a relative risk reduction of 22%, was consistent with the results seen in our monotherapy prophylaxis trials and, most importantly, with that routinely seen with the current standard-of-care drugs such as ondansetron."
He added "We have now completed the prophylaxis efficacy studies for BAREMSIS and the first of two treatment studies is well under way. Our aim is to receive an approval for the use of BAREMSIS in both the treatment and prophylaxis of PONV, alone and in combination. We anticipate submitting our NDA to the FDA in the second half of 2016."
The Phase 3 combination trial compared the prophylactic use of BAREMSIS plus a standard antiemetic (for example ondansetron or dexamethasone) against placebo plus a standard antiemetic. The primary endpoint was complete response, defined as no vomiting or retching and no requirement for antiemetic rescue medication in the first 24 hours after surgery.
The study was one of the largest PONV studies ever undertaken and was conducted at multiple sites in Europe and the US. It recruited a total of 1,204 surgical patients with 3 or 4 risk factors for PONV (the "Apfel risk factors"), of whom 1,147 were evaluable.
BAREMSIS significantly improved the complete response rate when added on top of a standard antiemetic compared to placebo and a standard antiemetic (57.7% vs 46.6%, p=0.0002). In addition, all secondary efficacy endpoints, including the rate of vomiting, nausea and use of rescue medication, were also met. The safety profile of BAREMSIS was excellent. No toxicities of note were seen and the profile of adverse events and laboratory abnormalities was as good as placebo. Detailed data will be presented in due course at relevant scientific meetings and submitted for publication in a peer-reviewed journal.
International consensus guidelines recommend the use of combinations of antiemetics from different mechanistic classes for the prevention of PONV in high-risk patients acknowledging the multiple biological pathways that are implicated in PONV. Currently two classes of antiemetics are predominantly used to prevent PONV in these patients, 5HT3 antagonists (usually ondansetron) and corticosteroids (usually dexamethasone). However, a safe and effective third mechanism antiemetic is required and BAREMSIS, as a dopamine antagonist, could fulfil this need.
NOTES TO EDITORS
About Acacia Pharma
Acacia Pharma is developing supportive care product opportunities for post-surgical and cancer patients. Patients and healthcare professionals urgently need new and improved interventions in these rapidly expanding, yet poorly served, areas of supportive care, to improve treatment outcomes and patients' quality of life.
Acacia Pharma has generated its pipeline of product opportunities using a commercially driven approach to product discovery, identifying completely new uses for marketed drugs, a process termed repurposing. This strategy leads to opportunities with a higher probability of success and enables more rapid development. All of Acacia Pharma's repurposed programmes are optimised for their new use, by using a new route of delivery and dose that are appropriate for the new indication identified, thereby differentiating them from the original marketed product.
The lead project, BAREMSIS for post-operative nausea & vomiting (PONV), has generated positive results in Phase 3 clinical studies. Its sister project, APD403 for chemotherapy induced nausea & vomiting (CINV) has successfully completed one Phase 2 dose-ranging study in patients receiving highly emetogenic chemotherapy. In addition, the company has completed a Phase 2 study with APD515 for xerostomia (dry mouth) in advanced cancer patients and a Phase 2a study with APD209 for cancer cachexia (muscle wasting).
Acacia Pharma, is led by an experienced management team. Management, Gilde Healthcare, Lundbeckfond Ventures, Novo A/S and F-Prime Capital are the Company's key shareholders. Acacia Pharma is based in Cambridge, UK and has US operations in Indianapolis, IN. http://www.acaciapharma.com
BAREMSIS (formerly APD421) comprises a low dose intravenous formulation of the marketed dopamine antagonist amisulpride, which Acacia Pharma has repurposed for the completely new, patent-protected use of management of PONV. Amisulpride is currently indicated for the management of psychoses, and is given at high doses in oral form. Amisulpride is not available for any use in the US.
Data generated by Acacia Pharma indicate that BAREMSIS is an effective, safe, dopamine antagonist. The company believes that a drug with these characteristics can be used prophylactically in combination with 5HT3 antagonists and/or corticosteroids in the highest risk patients and to rescue patients that have not responded to PONV prophylaxis with a 5HT3 antagonist alone or in combination.
Acacia Pharma is also developing APD403, with the same active ingredient, amisulpride, as in BAREMSIS, for the prevention of chemotherapy-induced nausea & vomiting ("CINV").
Post-operative nausea & vomiting (PONV) is a common complication of surgery which is distressing to patients and increases healthcare costs. In untreated patients, the incidence of vomiting is ~30%, the incidence of nausea is ~50% and the PONV rate in high-risk surgical patients is up to 80%. PONV is reported by patients as one of the most troublesome of all post-operative complications.
PONV can lead to prolonged discharge times and unanticipated hospital admissions (increasing healthcare costs) and to the possibility of reduced healthcare provider income as a consequence of Medicare's Hospital Readmissions Reduction Program and the pay-for-performance payment system in the Hospital Value-Based Purchasing (VBP) Program, in the US. The objective of PONV management, therefore, is to decrease the incidence of PONV, reducing patients' length of stay in the hospital, particularly the post-anaesthesia care unit (PACU), and avoiding hospital readmission, thereby reducing healthcare costs; and reducing patient distress, improving overall satisfaction, thereby optimising provider income through improved patient outcomes.
PONV risk factors
A simplified risk scoring system has been developed by Apfel et al to assess the risk of PONV in surgical patients. The four "Apfel risk factors" are:
- Being female
- Being a non-smoker
- Having a prior history of PONV or motion sickness
- An expected use of post-operative opioid analgesia.
Each of these four risk factors independently contributes around 20% risk of PONV. Patients with two "Apfel risk factors" are considered at moderate risk of PONV, while those with three or four are considered at high risk. A patient with all four risk factors has up to an 80% chance of PONV in the absence of effective prophylaxis.
Guidelines for the management of PONV
It is recommended that surgical patients are prescribed prophylactic antiemetics alone or in combination, according to their risk of PONV. Those considered at moderate risk of PONV should be given at least one prophylactic antiemetic and those at high risk of PONV, should be given multiple antiemetics of different mechanisms of action to optimise efficacy.
It is recommended that when a patient who has received antiemetic prophylaxis suffers PONV, an antiemetic from a different mechanism of action to that given prophylactically, is used to provide rescue treatment. Repeating the mechanism given prophylactically confers no additional benefit.
Current management of PONV
Two classes of drugs are predominantly used for the management of PONV: 5HT3 antagonists (eg ondansetron); and corticosteroids (eg dexamethasone). Ondansetron and dexamethasone have been investigated in many clinical studies and generally deliver a relative risk reduction (RRR) in the incidence of PONV of 15-30%,[ 6],[ 7].
The majority of surgical patients receiving prophylaxis are given a 5HT3 antagonist alone or in combination with a corticosteroid. However, Acacia Pharma believes that drug choices are limited in the highest risk patients where a third antiemetic of a different mechanism is required.
Up to 40% of patients experience PONV, requiring rescue medication, despite the routine use of prophylactic antiemetics. The majority of surgical patients have been given a prophylactic 5HT3 antagonist therefore precluding their use for rescue. Dexamethasone (a corticosteroid) has a slow onset of action and is not recommended for rescue. Therefore Acacia Pharma believes antiemetic choices for rescue are extremely limited.
Unmet need for a dopamine antagonist for PONV
Droperidol (a dopamine antagonist) was previously considered the drug of choice for PONV management until it received a boxed warning for QT-interval prolongation. A boxed warning is the most serious form of warning issued by the U.S. Food and Drug Administration for prescription drug products. The boxed warning and concerns about its side effect profile have severely limited the use of droperidol as an antiemetic.
Therefore there is currently no safe, effective, dopamine antagonist antiemetic available for anaesthetists to:
- Add to the most prevalent prophylactic regimen of a 5HT3 antagonist plus a corticosteroid, in the highest risk patients.
- Rescue patients having previously been given prophylaxis with a 5HT3 antagonist (alone or in combination).
 Gan et al, Anesthesia & Analgesia (2014) 118 1 85-113
 Apfel et al, N Engl J Med (2004) 350 2441-51
 Apfel et al, Anesthesiology (1999) 91 109-118
 Kovac et al, J Clin Anesth (1999) 11 453-459
 Fortney et al, Anesthesia & Analgesia (1998) 86 731-738
 Gan et al. Anesthesia & Analgesia (2011) 112 4 804-812
 Habib & Gan, J Clin Anesth (2008) 20 35-39
 Gan et al, Anesthesia & Analgesia (2007) 105 6 1615-1628
SOURCE Acacia Pharma