Schering AG and Biogen Idec announce start of the "ZEAL" Phase III Clinical
Trial with anti-cancer drug Zevalin(r)

Berlin and Cambridge, Massachusetts, October 4, 2006 - Schering AG, Germany
(FSE: SCH, NYSE: SHR) and Biogen Idec Inc. (NASDAQ: BIIB) today announced
the start of the ZEAL study (ZEVALIN as consolidation therapy in Aggressive
Lymphoma). Approximately 400 patients with Non-Hodgkin's Lymphoma (NHL)
will be enrolled in this Phase III, international multi-center clinical
trial.

The study will evaluate the efficacy and safety of Zevalin in patients with
Diffuse Large-B-cell Lymphoma (DLBCL) - the most common type of aggressive
Non-Hodgkin's Lymphoma. Patients are eligible if they are in complete
remission (CR) or unconfirmed complete remission (CRu) after first-line
CHOP-rituximab (CHOP-R) therapy. One group of patients will receive Zevalin,
the other group will be observed only without treatment. The trial is being
conducted in 46 U.S. and 57 European, Asian and Canadian centers.

The trial is an open-label, prospective, two-armed, randomized group-
sequential study. The duration of treatment will be two treatment days one
week apart followed by a 12-week period with intense observation. The total
duration of the trial is anticipated to be about 4 years. Entry criteria
include patients older than 60 years of age with DLBCL who are in complete
remission (CR or CRu) after six or eight cycles of first-line treatment
with CHOP chemotherapy in combination with rituximab (CHOP-R).

The primary endpoint for the trial is overall survival (OS), with disease-
free survival and health-related quality of life as secondary endpoints.
Once the final data from the trial are completed and analyzed, Schering AG
and Biogen Idec expect to file an application seeking to expand the
product's current label to include first-line therapy for patients with
aggressive DLBCL.

"Diffuse Large-B-cell Lymphoma is a disease that progresses very fast. It's
important that patients have options that provide the best efficacy
available, especially in this indication where a complete cure is the goal.
Therefore, Schering, along with our partner Biogen Idec, is confident that
with Zevalin we can bring a significant improvement to the treatment of
this disease," said Peter Zundorf, Head of Schering Group's Oncology Global
Business Unit.

Additional information

About Immunotherapy with Zevalin
Zevalin combines the tumor targeting ability of an anti-CD20 monoclonal
antibody and the cytotoxic power of Yttrium-90 radiation (so called
radioimmunotherapy), resulting in efficacy superior to antibody therapy
alone.

Zevalin binds to both malignant and normal B-cells, therefore patients
first receive a dose of an unlabeled antibody in order to remove normal
cells carrying the CD20 antigen from the peripheral blood system. With the
peripheral blood cleared of CD20 targets, the radiolabeled antibodies can
specifically bind to the cells in the tumor cluster. The treatment ensures
a high bio-availability at tumor sites and prevents the radioactivity from
being distributed through the body by circulating lymphocytes. Normal B-
cells are generally replenished by CD20-negative progenitor cells within
six to nine months after therapy.

Ninety percent of the effective energy of Yttrium-90 - as used with Zevalin
- - is deposited within a five-millimeter range, whereby any possible harmful
effects on healthy tissue can be kept to a minimum. Yttrium-90 emits only
beta radiation, so that hospitalization or patient isolation for several
days or even weeks after treatment is not required with Zevalin therapy.
Yttrium-90-Zevalin may be safely administered on an outpatient basis in the
U.S. and in most European countries.

It has been approved for relapsed or refractory low-grade follicular or
transformed B-cell non-Hodgkin's lymphoma (NHL) in the U.S. since 2002 and
for adult patients with rituximab-relapsed or refractory CD20-positive
follicular B-cell non-Hodgkin's lymphoma in Europe since 2004.

Earlier Zevalin Clinical Studies

A Phase II trial evaluating Zevalin as a second-line treatment for patients
with diffuse large B-cell lymphoma (DLBCL) who are not eligible for stem
cell transplantation: The study showed that Zevalin induced high response
rates in DLBCL patients who have relapsed or who are refractory to
combination chemotherapy (i.e. CHOP or CHOP-like) with or without rituximab.
Overall response rates (ORR) ranged from 20 percent to 58 percent in the
study. The highest observed complete response rate was up to 45 percent.
Durable responses were seen in all patient groups. Around 20 percent of the
patients are still in response after at least one year of follow-up
according to data presented at ASH in 2004 and at the 9th International
Congress on Malignant Lymphoma in Lugano in 2005. (Morschauser et al.)

A Phase II study explored the feasibility and effectiveness of first line
use of Zevalin and standard rituximab plus CHOP (R-CHOP) chemotherapy in
older patients with a high risk of diffused large B-cell lymphoma (DLBCL),
a disease that represents approximately one-third of all lymphomas and
primarily impacts people over 60 years of age: Patients received a CHOP
chemotherapy combined with Rituximab at standard doses for induction
therapy (R-CHOP). After the R-CHOP therapy and a period of six to nine
weeks for hematologic recovery, eligible patients with no disease
progression were treated with ZEVALIN. The interim evaluations show that
none of the patients receiving the full treatment regimen of ZEVALIN and R-
CHOP in this study relapsed within the 21-month median follow-up. (Hamlin
et al).

About NHL

Non-Hodgkin's lymphoma (NHL) is a type of malignant disease that occurs
within the lymphatic system. NHL is the fifth most common cancer after
breast, prostate, lung, and colon cancer. It originates from lymphocytes, a
type of white blood cells, which can be divided into two main types, B
lymphocytes and T lymphocytes (also called B-cells or T-cells). In adults,
approximately 85% of NHL cases are of B-cell origin.

The overall prevalence of NHL in the European Union is approximately
230,000, with an annual incidence of about 70,000. This incidence is
currently increasing in Europe by four per cent per year. Non-Hodgkin's
lymphomas can be divided into two general clinical categories: indolent
lymphomas, mainly typified as follicular lymphoma, which tend to grow
relatively slowly, and aggressive lymphomas, mainly typified as diffuse
large B-cell lymphoma (DLBCL), which grow more rapidly. DLBCL is the most
common lymphoma subtype, accounting for about 50 percent of all non-
Hodgkin's lymphomas among elderly patients. The aggressive type of NHL has
a shorter natural history, but a significant number of these patients can
be cured with combination chemotherapy regimens. However, the prognosis is
poor for patients who have relapsed or who are refractory following CHOP or
R-CHOP regimen. The prognosis is especially poor for those who are not
candidates for stem cell transplantation. The median age at diagnosis is
55-60 years. NHL is slightly more common in men than women. Risk factors
include pre-existing infection (particularly HIV, Epstein-Barr virus and T-
lymphotropic virus type 1), exposure to certain chemicals, previous organ
transplant and family history of the disease.


Schering AG is a research-based pharmaceutical company. Its activities are
focused on four business areas: Gynecology&Andrology, Oncology, Diagnostic
Imaging as well as Specialized Therapeutics for disabling diseases. As a
global player with innovative products, Schering AG aims for leading
positions in specialized markets worldwide. With in-house R&D and supported
by an excellent global network of external partners, Schering AG is
securing a promising product pipeline. Using new ideas, Schering AG aims to
make a recognized contribution to medical progress and strives to improve
the quality of life: making medicine work

It is planned that Schering AG will be renamed Bayer Schering Pharma
Aktiengesellschaft. A corresponding resolution was passed at the
Extraordinary General Meeting of Schering AG on September 13, 2006. Until
the name change has been registered in the commercial register, the company
will continue to operate under the name Schering AG. According to the
resolution of the General Meeting, the Executive Board will not file an
application for registration before December 1, 2006.


This press release has been published by Corporate Communication of
Schering AG, Berlin, Germany.

Your contacts at Corporate Communication:
Media Relations: Oliver Renner, T: +49-30-468 124 31,
oliver.renner@schering.de
Media Relations: Verena von Bassewitz, T: +49-30-468 19 22 06,
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Investor Relations:Dr. Jost Reinhard, T: +49-30-468 150 62,
jost.reinhard@schering.de
Pharma Communication: Dr Claudia Schmitt, T: +49-30-468 158 05,
claudia.schmitt@schering.de


Find additional information at: www.schering.de/eng