• BARHEMSYS is the first and only antiemetic to be approved for the rescue treatment of PONV in patients who have failed prior prophylaxis using current standard of care^1,2
• An estimated 16 million surgical patients each year in the US suffer from PONV despite receiving prophylaxis³
• BARHEMSYS is also approved for the prevention of PONV, either alone or in combination with an antiemetic of a different class
• Conference call scheduled for 10:00 am CET, Thursday 27 February

This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) No 596/2014.

Cambridge, UK and Indianapolis, US ? 27 February 2020:?Acacia Pharma Group plc (?Acacia Pharma? or the ?Company?) (EURONEXT: ACPH), a hospital pharmaceutical company focused on the development and commercialization of new products aimed at improving the care of patients undergoing significant treatments such as surgery, other invasive procedures, or cancer chemotherapy, announces that the US Food and Drug Administration (FDA) has approved BARHEMSYS^??(amisulpride injection) for the prevention and treatment of PONV in adult patients.

?The approval of our first product represents a significant milestone in Acacia Pharma?s evolution into an integrated hospital pharmaceutical company with strong development and commercialization capabilities,??commented Mike Bolinder, Acacia Pharma?s CEO. ?I would like to thank the Acacia Pharma team and stakeholders that have delivered this new treatment option for the millions of adult surgical patients each year suffering from, or at risk of, PONV. Our goal is for BARHEMSYS to become established as the new standard of care in the US for the treatment of PONV in patients who have failed standard prophylaxis, the area of highest unmet need. The results of our extensive clinical program also allow us to offer BARHEMSYS as an option for the prevention of PONV in higher-risk patients and settings, where combination prophylaxis can be valuable. We are on target with our commercial preparations and expect to launch BARHEMSYS in the second half of this year.?

Professor TJ Gan, Chairman of the Department of Anesthesiology at Stony Brook University in New York, said:??PONV remains a major problem for surgical patients and there have been few therapeutic advances over the past 20 years. It is often considered by patients to be the most undesirable complication of surgery, even worse than pain. It is therefore very welcome to be able to add BARHEMSYS to the treatment arsenal, especially for rescue treatment of patients failing standard prophylaxis, where we previously had no approved agent.?

?We are delighted that BARHEMSYS has gained FDA approval,??said Acacia Pharma?s Chief Medical Officer, Dr. Gabriel Fox. ?BARHEMSYS demonstrated significant benefits in the treatment and prevention of PONV in four pivotal trials. We are grateful to all the clinical investigators, hospital staff and, above all, patients who have made this approval possible through their participation in our clinical development program.?

BARHEMSYS is an intravenous formulation of the selective dopamine D₂?and D₃?antagonist amisulpride (2.5 mg/mL). The New Drug Application (NDA) submitted by Acacia Pharma for BARHEMSYS, which included four positive Phase 3 studies, contained data gathered from more than 3,300 surgical patients and healthy volunteers. The approval for BARHEMSYS covers the treatment of PONV in patients who have received antiemetic prophylaxis with an agent of a different class or who have not received prophylaxis and the prevention of PONV, either alone or in combination with an antiemetic of a different class.

The Company owns global rights to BARHEMSYS and intends to directly commercialize the product in the US through its own sales channel, having built critical sales, marketing, medical, and operational infrastructure and capabilities over the past two years. The Company plans to launch BARHEMSYS in 2H 2020.

In a randomized, double-blind, placebo-controlled study involving patients who had failed the most commonly used antiemetic prophylaxis, a single 10 mg dose of BARHEMSYS (n=230) was significantly more effective than placebo (n=235) at treating patients (42% vs 29%; p=0.003).¹?In a double-blind, randomized, placebo-controlled study in patients at the highest risk of suffering from PONV (Apfel score 3 or 4), a single 5 mg dose of BARHEMSYS in combination with another antiemetic (n=572) significantly improved protection from PONV compared to placebo plus another antiemetic (n=575; 58% vs 47%; p<0.001).⁴

The most common side effects observed across the four pivotal studies, reported in at least 2% of adult patients who received BARHEMSYS and at a higher rate than placebo were: infusion site pain (6% vs 4% with placebo), chills (4% vs 3%), hypokalemia (4% vs 2%), procedural hypotension (3% vs 2%), and abdominal distension (2% vs 1%). Serum prolactin concentrations were measured in one prophylaxis study where 5% (9/176) of BARHEMSYS-treated patients had increased blood prolactin reported as an adverse reaction compared to 1% (1/166) of placebo-treated patients.

Acacia Pharma?s second product, Byfavo? (remimazolam injection), was recently in-licensed from Cosmo Pharmaceuticals NV and an NDA is currently under review by FDA for use in procedural sedation in adults. The application has a target PDUFA action date of 5 April 2020. Subject to approval, the Company also intends to launch Byfavo in the US during 2020 and to commercialize Byfavo using the same sales and marketing infrastructure.

Conference Call Information

The Acacia Pharma management team will host a conference call today, Thursday 27 February 2020, at 10:00 am CET (09:00 am GMT).

Please join the event conference 5-10 minutes prior to the start using the password Acacia Pharma and any of the phone numbers provided below.

Password: Acacia Pharma

Belgium?????????? ??????????? 0800 746 68 The Netherlands???????? 0800 022 9132 United Kingdom????????? 0808 109 0700 United States? ??????????? 1 866 966 5335 International??? ??????????? +44 (0) 20 3003 2666

The conference call presentation can be accessed prior to the call by visiting the investors section of the Company?s website (Financial Reports and Presentations) at?www.acaciapharma.com. A recording of the conference call will be available in the same place for 30 days following the call.

Contacts

Acacia Pharma Group plc Mike Bolinder, CEO Christine Soden, CFO +44 1223 919760 IR@acaciapharma.com

Citigate Dewe Rogerson (Financial PR) Mark Swallow, Frazer Hall, David Dible +44 20 7638 9571 acaciapharma@citigatedewerogerson.com

About Acacia Pharma

Acacia Pharma is a hospital pharmaceutical company focused on the development and commercialization of new products aimed at improving the care of patients undergoing significant treatments such as surgery, other invasive procedures, or cancer chemotherapy. The Company has identified important and commercially attractive unmet needs in these areas that its product pipeline aims to address.

Acacia Pharma?s lead product, BARHEMSYS^??for postoperative nausea and vomiting (PONV), has been approved by the US FDA, with US launch planned for 2H 2020.

Byfavo? (remimazolam injection), an ultra-short-acting and reversible sedative/anesthetic investigated for use during invasive medical procedures, such as colonoscopy and bronchoscopy, is in-licensed from Cosmo Pharmaceuticals NV for the US market. The NDA for Byfavo has been filed with the US FDA, and the target PDUFA action date is 5 April 2020.

APD403 (intravenous and oral amisulpride), a selective dopamine antagonist for chemotherapy-induced nausea and vomiting (CINV), has successfully completed one proof-of-concept and one Phase 2 dose-ranging study in patients receiving highly emetogenic chemotherapy.

Acacia Pharma is based in Cambridge, UK, and its US operations are centered in Indianapolis, IN. The Company is listed on the Euronext Brussels exchange under the ISIN code GB00BYWF9Y76 and ticker symbol ACPH.

www.acaciapharma.com

About PONV

PONV is a common complication of surgery, occurring in approximately 30% of surgical patients and up to 80% of high-risk patients. It is associated with the use of anesthetic gases and opioid painkillers and is particularly common following gynecological, abdominal, breast, eye, and ear operations, especially those lasting an hour or more. PONV has been ranked as the most undesirable of all surgical complications in some patient surveys, even worse than pain.⁵

Acacia Pharma estimates that approximately 65 million surgical procedures are conducted in the US each year that are eligible for antiemetic use to prevent PONV. Based on market research, Acacia Pharma estimates that the total market in the US for high-risk prophylactic and rescue treatment comprises an estimated 34 million patients annually.³

About BARHEMSYS^?

BARHEMSYS is a selective dopamine-2 (D₂) and dopamine-3 (D₃) receptor antagonist, which Acacia Pharma has developed and protected for the management of PONV.

BARHEMSYS is indicated in adults for:

• treatment of PONV in patients who have received antiemetic prophylaxis with an agent of a different class or who have not received prophylaxis
• prevention of PONV, either alone or in combination with an antiemetic of a different class

www.BARHEMSYS.com

Important Safety Information for BARHEMSYS^??(amisulpride) Injection

Contraindication

BARHEMSYS is?contraindicated?in patients with known hypersensitivity to amisulpride.

QT Prolongation

BARHEMSYS causes dose- and concentration-dependent prolongation of the QT interval. The recommended dosage is 5 mg or 10 mg as a single intravenous (IV) dose infused over 1 to 2 minutes.

Avoid BARHEMSYS in patients with congenital long QT syndrome and in patients taking droperidol.

Electrocardiogram (ECG) monitoring is recommended in patients with pre-existing arrhythmias/cardiac conduction disorders, electrolyte abnormalities (e.g., hypokalemia or hypomagnesemia), congestive heart failure, and in patients taking other medicinal products (e.g., ondansetron) or with other medical conditions known to prolong the QT interval.

Adverse Reactions

Common adverse reactions reported in = 2% of adult patients who received BARHEMSYS 5 mg (n=748) and at a higher rate than placebo (n=741) in clinical trials for the prevention of PONV were: chills (4% vs. 3%), hypokalemia (4% vs. 2%), procedural hypotension (3% vs. 2%), and abdominal distention (2% vs. 1%).

Serum prolactin concentrations were measured in one prophylaxis study where 5% (9/176) of BARHEMSYS-treated patients had increased blood prolactin reported as an adverse reaction compared with 1% (1/166) of placebo-treated patients.

The most common adverse reaction, reported in = 2% of adult patients who received BARHEMSYS 10 mg (n=418) and at a higher rate than placebo (n=416), in clinical trials for the treatment of PONV was infusion site pain (6% vs. 4%).

Use in Specific Populations

Lactation Amisulpride is present in human milk. There are no reports of adverse effects on the breastfed child and no information on the effects of amisulpride on milk production.

BARHEMSYS may result in an increase in serum prolactin levels, which may lead to a reversible increase in maternal milk production. In a clinical trial, serum prolactin concentrations in females (n=112) increased from a mean of 10 ng/mL at baseline to 32 ng/mL after BARHEMSYS treatment and from 10 ng/mL to 19 ng/mL in males (n=61). No clinical consequences due to elevated prolactin levels were reported.

To minimize exposure to a breastfed infant, lactating women may consider interrupting breastfeeding and pumping and discarding breast milk for 48 hours after receiving a dose of BARHEMSYS.

Pediatric Use Safety and effectiveness in pediatric patients have not been established.

Geriatric Use No overall differences in safety or effectiveness were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

Renal Impairment Avoid BARHEMSYS in patients with severe renal impairment (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m²). The pharmacokinetics of amisulpride in patients with severe renal impairment have not been adequately studied in clinical trials. Amisulpride is known to be substantially excreted by the kidneys, and patients with severe renal impairment may have increased systemic exposure and an increased risk of adverse reactions.

No dosage adjustment is necessary in patients with mild to moderate renal impairment (eGFR = 30 mL/min/1.73 m²).

Drug Interactions

• BARHEMSYS causes dose- and concentration-dependent QT prolongation. To avoid potential additive effects, avoid use of BARHEMSYS in patients taking droperidol.
• ECG monitoring is recommended in patients taking other drugs known to prolong the QT interval (e.g., ondansetron).
• Reciprocal antagonism of effects occurs between dopamine agonists (e.g., levodopa) and BARHEMSYS. Avoid using levodopa with BARHEMSYS.

Please?click to access?full Prescribing Information for BARHEMSYS.

BAR HCP ISI 02/2020 PP-BAR-1062 02/2020 ? 2020 Acacia Pharma Group Plc BARHEMSYS^??is a registered trademark owned or licensed by Acacia Pharma Limited.

Forward looking statement

This announcement includes forward-looking statements, which are based on current expectations and projections about future events. These statements may include, without limitation, any statements preceded by, followed by or including words such as "believe", "expect", "intend", "may", "plan", "will", "should", "could" and other words and terms of similar meaning or the negative thereof. Forward-looking statements may and often do differ materially from actual results. These forward-looking statements are subject to risks, uncertainties and assumptions about the Company and its subsidiaries and investments, including, among other things, the development of its business, trends in its operating industry, and future capital expenditures and acquisitions. By their nature, forward-looking statements involve risk and uncertainty because they relate to future events and circumstances. Any forward-looking statements reflect the Company's current view with respect to future events and are subject to risks relating to future events and other risks, uncertainties and assumptions relating to the Group's business, results of operations, financial position, prospectus, growth or strategies and the industry in which it operates. Save as required by law or applicable regulation, the Company and its affiliates expressly disclaim any obligation or undertaking to update, review or revise any forward-looking statement contained in this announcement whether as a result of new information, future developments or otherwise. Forward-looking statements speak only as of the date they are made.

References

1. Habib?et al. Anesthesiology. 2019;130(2):203-212. 2. BARHEMSYS [package insert]. Indianapolis, IN: Acacia Pharma Inc; 2020. 3. Data on File. Acacia Pharma Inc. 4. Kranke?et al. Anesthesiology. 2018;128(6):1099-1106. 5. Gan TJ, et al.?Anesth Analg. 2014;118(1):85-113.