January 20, 2016
BTG Announces Presentation of New Vistogard® (uridine triacetate) Data at American Society of Clinic

London, UK, 20 January 2016

BTG plc (LSE: BTG) announced today the presentation of new data for Vistogard® (uridine triacetate) oral granules at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO-GI) 2016 (January 21-23). Vistogard® is the first and only antidote to overdose and early-onset, severe, or life-threatening toxicities from chemotherapy drugs 5-Fluorouracil (5-FU) or capecitabine, an orally administered prodrug of 5- FU. Vistogard® was approved on December 11, 2015 following a priority review by the United States Food and Drug Administration (FDA).

The data, which were included in the Vistogard® new drug application submitted to the FDA, will be presented as part of a poster session (Abstract #655 Poster Session C: Cancers of the Colon, Rectum, and Anus) on January 23 from 12:30-2:00 p.m. and 7:00-7:55 p.m. PT).

Principal investigator Wen Wee Ma, MD, Associate Professor of Oncology, GI Cancers & Drug Development Program, Roswell Park Cancer Institute, commented: “These data are particularly important for the gastrointestinal oncology community and for patients because 5-FU and capecitabine are the most commonly used chemotherapies for solid GI tumors, alone or in combination with other treatments. The toxicities that can result from overexposure historically have been very difficult to treatand, for many patients, can lead to prolonged and unnecessary suffering. Further, these toxicities can lead to death.These data show that uridine triacetate rapidly counteracts these potentially life-threatening toxicities.”

The poster details data in 135 patients overdosed with 5-FU or capecitabine or exhibiting early onset of severe toxicities, including CNS, cardiac, GI and/or hematologic toxicities due to dihydropyrimidine dehydrogenase (DPD) deficiency, other genetic variants, or other factors resulting in excessive susceptibility to 5-FU or capecitabine. The patients were treated with a single course of 10 grams of Vistogard® given orally every six hours for a total of 20 doses.Clinical endpoints included survival compared with historical controls, time to resumption of chemotherapy, and safety.

The results show that 96% of patients treated with Vistogard® recovered fully within 30 days of receiving treatment with Vistogard®. Further, 38% of overdose patients resumed chemotherapy within 30 days (overall median time of 20 days). Comparatively, only 19% of historical cases employing standard supportive care measures survived.

Generally mild adverse events of vomiting, nausea, and diarrhea, were attributed infrequently and, in most cases, as possibly related to Vistogard®.

Selected Important Safety Information for Vistogard® (uridine triacetate) oral granules

INDICATION

Vistogard® is indicated for the emergency treatment of adult and pediatric patients:

• following a fluorouracil or capecitabine overdose regardless of the presence of symptoms, or
• who exhibit early-onset, severe or life-threatening toxicity affecting the cardiac or central nervous system, and/or early-onset, unusually severe adverse reactions (e.g., gastrointestinal toxicity and/or neutropenia) within 96 hours following the end of fluorouracil or capecitabine administration.

Limitations of use:

• Vistogard® is not recommended for the non-emergent treatment of adverse reactions associated with fluorouracil or capecitabine because it may diminish the efficacy of these drugs.
• The safety and efficacy of Vistogard® initiated more than 96 hours following the end of fluorouracil or capecitabine administration have not been established.

IMPORTANT SAFETY INFORMATION

• In clinical studies, adverse reactions occurring in > 2% patients receiving Vistogard® were vomiting (10%), nausea (5%) and diarrhea (3%).
• One patient receiving uridine triacetate experienced grade 3 nausea and vomiting.

Please see full Prescribing Information.

About Vistogard®(uridine triacetate) oral granules

Vistogard® (uridine triacetate) is an orally administered drug approved by the FDA on December 11, 2015 to treat patients following an overdose of 5-fluorouracil (5-FU) or capecitabine or in patients exhibiting early-onset, severe or life- threatening toxicity affecting the cardiac or central nervous system, and/or early-onset, unusually severe adverse reactions (e.g., gastrointestinal toxicity and/or neutropenia) within 96 hours following the end of 5-FU or capecitabine administration. Vistogard® received orphan drug designation from the FDA as an antidote in the treatment of 5-FU poisoning and from the European Medicines Agency (EMA) as a treatment for 5-FU overdose. In Europe, under a named patient program, Vistogard® is currently provided to patients at risk of excess 5-FU toxicity due to overdose and patients exhibiting severe toxicities to 5-FU within 96 hours of 5-FU administration.

Wellstat Therapeutics developed Vistogard® and BTG will market, sell and distribute the drug for this indication in the US.

For more information please visit www.Vistogard.com.

About 5-Fluorouracil (5-FU)

5-FU is on the World Health Organization’s List of Essential Medicines, a compilation of the most important medications needed in a basic health system. Because 5-FU is administered in different doses and schedules as a frequent component of standard chemotherapy regimens for a variety of cancers, patients can experience dramatically different patterns of toxicity.

Used in combination with other chemotherapy agents and/or radiation, 5-FU has been for decades a mainstay of various treatment regimens for solid tumors, including those of the colon, pancreas, stomach, esophagus, breast, and head and neck. GI cancers are one of the most common types of cancer, with more than 180,000 people in the United States and more than three million worldwidediagnosed each year with colon, pancreas, stomach or esophagus cancers.

The drug is most commonly administered by infusion pump at or near what is considered the maximum tolerated dose. Expected side effects of 5-FU include myelosuppression (a reduction in white-blood-cell counts and thus increased risk of infection), diarrhea, nausea, vomiting, and mucositis (a painful inflammation and ulceration of the mucous membranes lining the digestive tract). Overexposure to 5-FU can lead to severe myelosuppression, gastrointestinal hemorrhage, septic shock, multiple organ failure, cardiac and neurological complications, and death.

About Capecitabine

Capecitabine is an orally administered chemotherapy prodrug 5-FU that is enzymatically activated within the body and transformed into 5-FU. When capecitabine comes into contact with a naturally occurring protein called thymidine phosphorylase, capecitabine is transformed into 5-FU. Because many cancers have higher levels of thymidine phosphorylase than do normal tissues, more 5-FU is delivered to the tumor than to other tissue.

About Wellstat Therapeutics

Wellstat Therapeutics Corporation is a privately-held biopharmaceutical company located in Gaithersburg, Maryland. Wellstat Therapeutics is committed to discovering, developing and commercializing products that will provide new and improved treatments for patients in the fields of oncology and metabolic, neurometabolic and neurodegenerative diseases. For more information, please visit the website at http://www.wellstattherapeutics.com. Wellstat Therapeutics is part of the Wellstat group of companies (http://www.wellstat.com).

About BTG

BTG is a growing international specialist healthcare company bringing to market innovative products in specialist areas of medicine to better serve doctors and their patients. We have a portfolio of Interventional Medicine products to advance the treatment of liver tumors, advanced emphysema, severe blood clots and varicose veins, and Specialty Pharmaceuticals that help patients overexposed to certain medications or toxins. Inspired by patient and physician needs, BTG is investing to expand its portfolio to address some of today’s most complex healthcare challenges. To learn more about BTG, please visit: www.btgplc.com

Contacts

BTG
Stuart Hunt, Investor Relations Manager
+44 (0)20 7575 1582
Mobile: +44 (0)7815 778 536

Chris Sampson, Corporate Communications Director
+44 20 7575 1595
Mobile: +44 7773 251 178

GCI Health
Maura Siefring, 917-216-8333

Vistogard is a registered trademark of Wellstat Therapeutics Corporation.