Ferumoxytol Treatment Produced Significant Hemoglobin Increases in Adult Iron Deficiency Anemia Patients With Gastrointestinal

Ferumoxytol Treatment Produced Significant Hemoglobin Increases in Adult Iron
Deficiency Anemia Patients With Gastrointestinal Disease Who Had Failed or
Could Not Tolerate Oral Iron Therapy

Sub-Group Analysis of a Phase III Trial Being Presented Today in a Poster
Session at Digestive Disease Week

LEXINGTON, Mass., May 21, 2013 (GLOBE NEWSWIRE) -- AMAG Pharmaceuticals, Inc.
(Nasdaq:AMAG) announced that a new sub-group analysis from IDA-301, a phase
III, randomized, placebo-controlled clinical trial, will be presented today at
a poster session of the Digestive Disease Week 2013 (DDW) meeting in Orlando,
Florida. In the full IDA-301 study, 608 adult patients with iron deficiency
anemia (IDA) who had failed or could not tolerate oral iron were treated with
ferumoxytol and 200 received placebo. The sub-group analysis being presented
today at DDW is based on 231 patients in IDA-301 with gastrointestinal (GI)
disease. Of these patients, 173 were randomized to the ferumoxytol treatment
arm and 58 to the placebo arm.

IDA-301 was a multicenter trial designed to compare the safety and efficacy of
a one gram course of ferumoxytol versus placebo in adult patients with IDA who
had failed or could not tolerate oral iron treatment, regardless of the
underlying cause. Ferumoxytol is an IV iron treatment currently approved in
the United States for the treatment of IDA in adult chronic kidney disease
patients. IDA-301 was one of two studies that formed the foundation for AMAG's
supplemental new drug application (sNDA) in the United States, which was filed
in December 2012. AMAG's sNDA seeks to expand the use of Feraheme®
(ferumoxytol) for adult IDA patients who have failed or could not tolerate
oral iron, including those patients with GI disease.

The primary efficacy endpoint of this study for the U.S. Food and Drug
Administration (FDA) is the proportion of subjects who achieved a > 2.0 g/dL
increase in hemoglobin at any time from baseline to week 5; the primary
efficacy endpoint for European Union (EU) regulators is the mean change in
hemoglobin from baseline to week 5. In the GI sub-group analysis, 82.1% of
ferumoxytol-treated patients achieved an increase of > 2.0 g/dL in hemoglobin
compared to 1.7% of patients who received placebo at week 5, meeting the
protocol defined measure of superiority (p<0.0001). The mean change in
hemoglobin in ferumoxytol-treated GI patients from baseline to week 5 was 2.8
g/dL, compared to no increase (-0.1 g/dL) in GI patients receiving placebo
(p<0.0001). These results paralleled those in the total study population.

As a pre-defined secondary endpoint in the IDA-301 study, patients were asked
to report on measures of fatigue using the Functional Assessment of Chronic
Illness Therapy (FACIT) instrument. Patients in the GI sub-group treated with
ferumoxytol demonstrated an 11.6 point improvement in self-reported fatigue
compared to a 7.9 point improvement in those who received placebo (p=0.0335).

"Patients with GI disease, including inflammatory bowel disease, often develop
iron deficiency anemia, and most live with the symptoms associated with IDA,
including extreme fatigue, " said Dr. Charles F. Barish, a gastroenterologist
at Wake Gastroenterology in Raleigh, North Carolina and a Principal
Investigator in the trial. "The data from this study showed a direct
correlation between a rise in hemoglobin levels and improvements in patients'
self-reported measures of fatigue. GI patients with iron deficiency anemia who
have not responded well to oral iron supplementation have a need for
additional treatment options. The analysis from this study supports the
potential of ferumoxytol as a new treatment option for patients with IDA from
GI disease who have previously had an unsatisfactory response to oral iron
therapy."

In the GI sub-group, the rate of reported adverse events (AEs) was higher
among ferumoxytol-treated patients (48.6%) than in patients that received
placebo (44.8%). The overall rate of serious adverse events (SAEs) was
comparable between the two treatment groups, with SAEs reported in 2.9% of
ferumoxytol-treated patients, compared to 3.4% of patients that received
placebo. Related AEs and AEs of special interest were higher in
ferumoxytol-treated patients in both the overall population and in patients
with GI disease. However, the incidence of reported AEs was consistent with
that seen in the overall IDA population.

Poster Information

The poster, entitled "Evaluation of Ferumoxytol Treatment for Iron Deficiency
Anemia in Patients with Gastrointestinal Disorders who have a History of
Unsatisfactory Oral Iron Therapy: Results of a Phase III, Randomized,
Placebo-Controlled Study," located at Hall WA1, will be presented on Tuesday,
May 21, from 8:00 a.m. to 5:00 p.m., and poster authors will be available for
a question-and-answer session from noon to 2:00 p.m.

About Iron Deficiency Anemia

More than 4 million Americans have iron deficiency anemia, many of whom are
patients with gastrointestinal disease including bleeding in the upper and/or
lower bowel, inflammatory bowel disease and malabsorption disorders.^1Other
causes of IDA include chronic kidney disease, abnormal uterine bleeding,
inflammatory diseases and chemotherapy-induced anemia.Many IDA patients fail
treatment with oral iron due to intolerability, lack of absorption or side
effects.

About AMAG

AMAG Pharmaceuticals, Inc. is a specialty pharmaceutical company that
manufactures and markets Feraheme® in the United States. Along with driving
organic growth of its lead product, AMAG intends to expand its portfolio with
additional commercial-stage specialty pharmaceuticals. The company is seeking
complementary products that leverage the company's commercial footprint and
focus on hematology and oncology centers and hospital infusion centers. For
additional company information, please visit www.amagpharma.com.

About Feraheme® (ferumoxytol)/Rienso

In the United States, Feraheme (ferumoxytol) Injection for Intravenous (IV)
use is indicated for the treatment of iron deficiency anemia in adult chronic
kidney disease (CKD) patients. Feraheme received marketing approval from the
U.S. Food and Drug Administration on June 30, 2009 and was commercially
launched by AMAG in the U.S. shortly thereafter.

Ferumoxytol is protected in the U.S. by three issued patents covering the
composition and dosage form of the product. Each issued patent is listed in
the FDA's Orange Book. These patents are set to expire in 2020; a request for
patent term extension has been filed, which, if granted, may extend the patent
term to 2023 for one of the patents.

Ferumoxytol received marketing approval in Canada in December 2011, where it
is marketed by Takeda as Feraheme, and in the European Union in June 2012 and
Switzerland in August 2012, where it is marketed by Takeda as Rienso®.

Feraheme is contraindicated in patients with known hypersensitivity to
Feraheme or any of its components.

Serious hypersensitivity reactions, including anaphylactic-type reactions,
some of which have been life-threatening and fatal, have been reported in
patients receiving Feraheme. Observe patients for signs and symptoms of
hypersensitivity during and after Feraheme administration for at least 30
minutes and until clinically stable following completion of each
administration. Only administer the drug when personnel and therapies are
immediately available for the treatment of anaphylaxis and other
hypersensitivity reactions.Anaphylactic-type reactions, presenting with
cardiac/cardiorespiratory arrest, clinically significant hypotension, syncope,
and unresponsiveness have been reported in the post-marketing experience.In
clinical studies conducted as part of the CKD development program, serious
hypersensitivity reactions were  reported in 0.2% (3/1,726) of subjects
receiving Feraheme. Other adverse reactions potentially associated with
hypersensitivity (e.g., pruritus, rash, urticaria or wheezing) were reported
in3.7% (63/1,726) of subjects.

Severe adverse reactions of clinically significant hypotension have been
reported in the post-marketing experience of Feraheme. In clinical studies
conducted as part of the CKD development program, hypotension was reported in
1.9% (33/1,726) of subjects, including three patients with serious hypotensive
reactions. Monitor for signs and symptoms of hypotension following each
Feraheme injection.

Excessive therapy with parenteral iron can lead to excess storage of iron with
the possibility of iatrogenic hemosiderosis. Patients should be regularly
monitored for hematologic response during parenteral iron therapy, noting that
lab assays may overestimate serum iron and transferrin bound iron values in
the 24 hours following administration of Feraheme.

As a superparamagnetic iron oxide, Feraheme may transiently affect magnetic
resonance diagnostic imaging studies for up to 3 months following the last
Feraheme dose. Feraheme will not affect X-ray, CT, PET, SPECT, ultrasound, or
nuclear imaging.

In clinical trials of patients with IDA and CKD, the most commonly occurring
adverse reactions in Feraheme treated patients versus oral iron treated
patients (reported in ≥ 2% of patients) were diarrhea (4.0% vs. 8.2%), nausea
(3.1% vs. 7.5%), dizziness (2.6% vs. 1.8%), hypotension (2.5% vs. 0.4%),
constipation (2.1% vs. 5.7%) and peripheral edema (2.0% vs. 3.2%). In these
trials, adverse reactions leading to treatment discontinuation and occurring
in 2 or more Feraheme treated patients included hypotension, infusion site
swelling, increased serum ferritin level, chest pain, diarrhea, dizziness,
ecchymosis, pruritus, chronic renal failure, and urticaria.

For additional U.S. product information, including full prescribing
information, please visit www.feraheme.com.

Forward-looking Statements

This press release contains forward-looking statements within the meaning of
the Private Securities Litigation Reform Act of 1995 and other federal
securities laws. Any statements contained herein which do not describe
historical facts, including but not limited to statements regarding: the
sub-group analysis on GI patients in IDA-301 , the expectations and expected
timing for regulatory review of the submission and outcome of the supplemental
new drug application for the broader IDA indication and the availability of
treatment options for patients, and the company's interactions with the FDA,
are forward-looking statements which involve risks and uncertainties that
could cause actual results to differ materially from those discussed in such
forward-looking statements.

Such risks and uncertainties include: (1) uncertainties regarding our and
Takeda's ability to successfully compete in the intravenous iron replacement
market both in the US and outside the US, including the EU, (2) uncertainties
regarding our ability to successfully and timely complete our clinical
development programs and obtain regulatory approval for Feraheme/Rienso in the
broader IDA indication both in the US and outside of the US, including the EU,
(3) the possibility that significant safety or drug interaction problems could
arise with respect to Feraheme/Rienso, (4) uncertainties regarding the
manufacture of Feraheme/Rienso, (5) uncertainties relating to our patents and
proprietary rights, both in the US and outside of the US, (6) the risk of an
Abbreviated New Drug Application (ANDA) filing following the FDA's recently
published draft bioequivalence recommendation for ferumoxytol, and (7) other
risks identified in our Securities and Exchange Commission filings, including
our Quarterly Report on Form 10-Q for the three months ended March 31, 2013
and subsequent filings with the SEC. We caution you not to place undue
reliance on any forward-looking statements, which speak only as of the date
they are made.

We disclaim any obligation to publicly update or revise any such statements to
reflect any change in expectations or in events, conditions or circumstances
on which any such statements may be based, or that may affect the likelihood
that actual results will differ from those set forth in the forward-looking
statements.

AMAG Pharmaceuticals and Feraheme are registered trademarks of AMAG
Pharmaceuticals, Inc.

Rienso is a registered trademark of Takeda Pharmaceutical Company Limited.

^1Source: Cancer - US Census, Age-adjusted SEER incidence, primary market
research, "Managing patients with Chemotherapy induced
anemia":(2008),"Saving costs in cancer anemia management. Recognizing
functional iron deficiency (FID) and rationalizing EPO therapy." (2002). GI -
US Census, USRDS, DataMonitor Pipeline Insight: Inflammatory Bowel Disease,
studies by Kappelman, and Tack, http://www.uchospitals.edu/pdf/uch_007937.pdf,
http://www.ncbi.nlm.nih.gov/pubmed/15932566,
http://www.haematologica.org/cgi/reprint/haematol.2009.009985v1.pdf. AUB and
PP - AMAG primary market research,
http://www.mdguidelines.com/dysfunctional-uterine-bleeding, National Vital
Statistics Reports (NVSR),
http://emedicine.medscape.com/article/257007-overview, "Have we forgotten the
significance of postpartum iron deficiency?" (2005).

CONTACT: AMAG Pharmaceuticals, Inc. Contact:
         Amy Sullivan, 617-498-3303