Jazz Pharmaceuticals Begins Clinical Trial of Intravenously Administered Erwinaze® In Patients with Acute Lymphoblastic

   Jazz Pharmaceuticals Begins Clinical Trial of Intravenously Administered
           Erwinaze® In Patients with Acute Lymphoblastic Leukemia

  PR Newswire

  DUBLIN, Dec. 3, 2012

DUBLIN, Dec. 3, 2012 /PRNewswire/ -- Jazz Pharmaceuticals plc (Nasdaq: JAZZ)
today announced that the first patient has been enrolled and dosed in a
clinical trial of Erwinaze® (asparaginase Erwinia chrysanthemi ) administered
intravenously (IV) as an alternative method of administration to treat
patients with acute lymphoblastic leukemia (ALL) with hypersensitivity to E.
coli -derived asparaginase therapy.

"Intravenous administration of Erwinaze may provide meaningful benefit to
patients, their caregivers and families by avoiding the need for multiple
intramuscular injections," stated Lynda Vrooman, MD, MSc, a pediatric
oncologist at Dana-Farber/Children's Hospital Cancer Center and principal
investigator of the trial. "Intramuscular injections can be painful and
difficult for patients, and this alternative route of administration, if it is
shown to be feasible, would be an important advancement in the care of certain
ALL patients, many of whom are young children."

The trial is designed to enroll up to 25 ALL patients in the U.S. and Canada
who have a documented Grade 2 or higher hypersensitivity reaction to native or
pegylated E. coli asparaginase and have not completed their full courses of
prescribed asparaginase therapy. Preliminary pharmacokinetic data from the
trial are expected in the second half of 2013.

"This important clinical trial underscores our commitment to those patients
with ALL who require treatment with Erwinaze," noted Jeffrey Tobias, MD,
executive vice president of research and development, and chief medical
officer of Jazz Pharmaceuticals. "It also reflects our strategy of supporting
our core growth products by investment in patient-centric initiatives."

About Acute Lymphoblastic Leukemia (ALL) Acute lymphoblastic leukemia affects
approximately 6,000 Americans, 60 percent of whom are children. ALL is the
most common form of childhood cancer, with the peak incidence between two and
five years of age. ALL has a 90 percent survival rate with treatment
including asparaginase-based regimens, but progresses quickly if left
untreated. A majority of asparaginase treatments derive from E. coli;
however, approximately 15 to 20 percent of ALL patients develop
hypersensitivity to E. coli- derived asparaginase regimens. Erwinaze
asparaginase-based therapy plays a critical role for patients with no other
treatment options.

About Jazz Pharmaceuticals Jazz Pharmaceuticals plc is a specialty
biopharmaceutical company focused on improving patients' lives by identifying,
developing and commercializing innovative products that address unmet medical
needs. The company has a diverse portfolio of products in the areas of
narcolepsy, oncology, pain and psychiatry. The company's U.S. marketed
products in these areas include: Xyrem® (sodium oxybate) oral solution,
Erwinaze® (asparaginase Erwinia chrysanthemi ), Prialt® (ziconotide)
intrathecal infusion, Luvox CR® (fluvoxamine maleate), FazaClo® (clozapine,
USP) HD and FazaClo LD. Outside of the U.S.,Jazz Pharmaceuticalsalso has a
number of products marketed by its international division, EUSA Pharma.

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of
1995 This press release contains forward-looking statements, including, but
not limited to, statements related to enrollment and data collection in the
Erwinaze IV administration trial and the timing thereof, the potential for
future patient benefit from IV administration of Erwinaze, future product
growth and investment and other statements that are not historical facts.
These forward-looking statements are based onJazz Pharmaceuticals' current
expectations and inherently involve significant risks and uncertainties.
Actual results and the timing of events could differ materially from those
anticipated in such forward-looking statements as a result of these risks and
uncertainties, which include, without limitation, risks related to the
difficulty and uncertainty of pharmaceutical product development and the
uncertainty of clinical success and regulatory approval, including the risks
that the results from the clinical trial may be negative or inconclusive,
which could preclude FDA approval of IV administration of Erwinaze and could
result in adverse regulatory action related to the company's current Erwinaze
commercial product, other risks relatedJazz Pharmaceuticals' business,
including dependence on sales of Xyrem® and the company's ability to maintain
and increase sales of Xyrem and other products, including Erwinaze, and those
other risks detailed from time to time under the caption "Risk Factors" and
elsewhere inJazz Pharmaceuticals' filings and reports with the Securities
and Exchange Commission (Commission File No.001-33500), including inJazz
Pharmaceuticals' Quarterly Report on Form 10-Q for the quarter endedSeptember
30, 2012 and future filings and reports by the company. Jazz
Pharmaceuticalsundertakes no duty or obligation to update any forward-looking
statements contained in this press release as a result of new information,
future events or changes in its expectations.

Contact: Ami Knoefler, Executive Director, Investor Relations & Corporate
Communications, Jazz Pharmaceuticals plc, Ireland, +353-1-638-1032, U.S.,
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