Horizon Pharma Announces Collaboration With Fox Chase Cancer Center To Study ACTIMMUNE (Interferon Gamma-1b) In Combination With PD-1/PD-L1 Inhibitors In Various Forms Of Cancer

DUBLIN, IRELAND--(Marketwired - July 27, 2015) - Horizon Pharma plc (NASDAQ: HZNP), a biopharmaceutical company focused on improving patients’ lives by identifying, developing, acquiring and commercializing differentiated products that address unmet medical needs, today announced a collaboration with Fox Chase Cancer Center to study ACTIMMUNE (interferon gamma-1b) in combination with PD-1/PD-L1 inhibitors in various forms of cancer including advanced urothelial carcinoma (bladder cancer) and renal cell carcinoma.

Preclinical cell line research has indicated that interferon gamma enhances cellular PD-L1 expression on endothelial cells (inner lining of the blood vessel) and on some tumor cells. By enhancing cellular PD-L1 expression on tumor cells, interferon gamma may promote or enhance the effect of the PD-1 or PD-L1 inhibitors.

“This collaboration with Fox Chase Cancer Center is an important step in determining if the addition of ACTIMMUNE to a treatment regimen including a PD-1 and PD-L1 inhibitor can enhance the effect of these agents and potentially improve patient outcomes,” said Jeffrey Sherman, M.D., FACP, executive vice president, research and development and chief medical officer, Horizon Pharma plc. “Through this research, our goal is to gain a better understanding of the potential for ACTIMMUNE along with PD-1 and PD-L1 inhibitors in different patient populations and disease areas.”

The first study being planned as part of the collaboration will be a dose-ranging study to determine a suitable dose for ACTIMMUNE with PD-1/PD-L1 inhibition. Once the ideal combination strategy is determined, the investigators intend to expand the study to include patients with metastatic bladder and renal cell carcinomas. Additional studies are expected to follow depending on initial results.

About ACTIMMUNE®
ACTIMMUNE (interferon gamma-1b) is a biologically manufactured protein similar to one the body makes naturally to help prevent infection. ACTIMMUNE is currently approved by the U.S. Food and Drug Administration (FDA) for use in two rare diseases. It is indicated to reduce the frequency and severity of serious infections associated with Chronic Granulomatous Disease (CGD), a genetic disorder that affects the functioning of some cells of the immune system. In addition, ACTIMMUNE is indicated to slow the worsening of severe, malignant osteopetrosis (SMO), a genetic disorder that affects normal bone formation. For more information, please see www.ACTIMMUNE.com.

Indications and Usage
Chronic Granulomatous Disease (CGD)
ACTIMMUNE is approved by the US Food and Drug Administration to reduce the frequency and severity of serious infections associated with Chronic Granulomatous Disease. CGD is a genetic disorder that affects the functioning of some cells of the immune system.

Severe, Malignant Osteopetrosis (SMO)
ACTIMMUNE is approved by the US Food and Drug Administration to slow the worsening of severe, malignant osteopetrosis. SMO is also a genetic disorder that affects normal bone formation.

Important Safety Information (ISI)
The most common side effects with ACTIMMUNE are “flu like” symptoms, such as fever, headache, chills, myalgia (muscle pain), or fatigue, which may decrease in severity as treatment continues. Bedtime administration of ACTIMMUNE may minimize these symptoms. Acetaminophen may be helpful in preventing fever and headache.

ACTIMMUNE can cause severe allergic reactions and/or rash. Do not use ACTIMMUNE if you are allergic to interferon-gamma, E. col-derived products, or any component of the product. (See Full Prescribing Information for a list of components). If you develop a serious reaction to ACTIMMUNE discontinue it immediately and contact your doctor or seek medical help.

At high doses, ACTIMMUNE can cause (flu-like) symptoms, which may worsen some pre-existing heart conditions. Tell your doctor if you have a cardiac condition, such as irregular heartbeat, heart failure, or decreased blood flow to your heart.

ACTIMMUNE may cause reversible changes to your nervous system, including decreased mental status, walking disturbances, and dizziness. Tell your doctor if you have a history of seizures or other neurological disorders.

Bone marrow function may be suppressed with ACTIMMUNE and decreased production of cells important to the body may occur. This effect, which can be severe, is usually reversible when the drug is discontinued or the dose is reduced. Tell your doctor if you have, or have had reduced bone marrow function. Your doctor will monitor these cells with blood tests at the beginning of therapy and at 3 month intervals thereafter.

Taking ACTIMMUNE may cause reversible changes to your liver function, particularly in patients less than one year old. Your doctor will monitor your liver function at the beginning of therapy and at 3 month intervals thereafter.

If you are pregnant or plan to become pregnant or plan to nurse you should consult your physician.

If you are receiving ACTIMMUNE at home, your doctor will provide to you or your caregiver appropriate instructions on the administration of the drug and disposal of the container, needles and syringes.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

This information is not intended to replace discussions with your doctor. For additional information about ACTIMMUNE, please consult the Full Prescribing Information and the Information for the Patient/Caregiver and talk to your doctor. ACTIMMUNE is available by prescription only.

Visit www.ACTIMMUNE.com to download a copy of the ACTIMMUNE Full Prescribing Information.

About Horizon Pharma plc
Horizon Pharma plc is a biopharmaceutical company focused on improving patients’ lives by identifying, developing, acquiring and commercializing differentiated and accessible medicines that address unmet medical needs. The Company markets seven medicines through its orphan, primary care and specialty business units. Horizon’s global headquarters are in Dublin, Ireland. For more information, please visit www.horizonpharma.com.

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Forward Looking Statements
This press release contains forward-looking statements, including statements regarding potential clinical trials evaluating ACTIMMUNE in additional indications such as urothelial carcinoma (bladder cancer), renal cell carcinoma. Forward-looking statements speak only as of the date of this press release and Horizon does not undertake any obligation to update or revise these statements, except as may be required by law. These forward-looking statements are based on management’s expectations and assumptions as of the date of this press release and actual results may differ materially from those in these forward-looking statements as a result of various factors. These factors include, but are not limited to, risks regarding whether Horizon will be able to continue its collaboration with Fox Chase Cancer Center, whether the parties will comply with their obligations under the collaboration, whether Horizon will conduct further studies of ACTIMMUNE or have the financial resources to do so, and the risks associated with pre-clinical and clinical development of drug candidates. For a further description of these and other risks facing Horizon, please see the risk factors described in Horizon’s filings with the United States Securities and Exchange Commission, including those factors discussed under the caption “Risk Factors” in those filings. Forward-looking statements speak only as of the date of this press release and Horizon undertakes no obligation to update or revise these statements, except as may be required by law.