Genmab — Earnings Release 2011

Feb 7, 2012

• Arzerra worldwide net sales in Q4 2011 totaled GBP 11.7 million
• Full year 2011 Arzerra sales were GBP 43.5 million, an increase of 40% over
  2010
• Genmab royalty income is approximately DKK 20 million for Q4 and
  approximately DKK 75 million for the full year

Copenhagen, Denmark; February 7, 2012 – Genmab A/S (OMX: GEN) announced today
that the Arzerra® (ofatumumab) net sales during the fourth quarter of 2011 were
GBP 11.7 million. This figure consists of net sales in the U.S. of GBP 8.2
million and in the rest of the world GBP 3.5 million. Under the terms of the
collaboration with GlaxoSmithKline (GSK), Genmab expects to receive a royalty
payment of approximately DKK 20 million.

Full year 2011 net sales of Arzerra totaled GBP 43.5 million worldwide,
resulting in total royalty income to Genmab of approximately DKK 75 million for
the year.

The conversion from GBP to DKK has been made using the Danish Central Bank
average rates for the respective quarters in 2011.

About Genmab A/S
Genmab is a publicly traded, international biotechnology company specializing
in the creation and development of differentiated human antibody therapeutics
for the treatment of cancer. Founded in 1999, the company’s first marketed
antibody, ofatumumab (Arzerra®), was approved to treat chronic lymphocytic
leukemia in patients who are refractory to fludarabine and alemtuzumab after
less than eight years in development. Genmab’s validated and next generation
antibody technologies are expected to provide a steady stream of future product
candidates. Partnering of innovative product candidates and technologies is a
key focus of Genmab’s strategy and the company has alliances with top tier
pharmaceutical and biotechnology companies. For more information visit
www.genmab.com.

Contact:
Rachel Curtis Gravesen, Senior Vice President, Investor Relations &
Communication
T: +45 33 44 77 20; M: +45 25 12 62 60; E: r.gravesen@genmab.com

This Company Announcement contains forward looking statements. The words
“believe”, “expect”, “anticipate”, “intend” and “plan” and similar expressions
identify forward looking statements. Actual results or performance may differ
materially from any future results or performance expressed or implied by such
statements. The important factors that could cause our actual results or
performance to differ materially include, among others, risks associated with
pre-clinical and clinical development of products, uncertainties related to the
outcome and conduct of clinical trials including unforeseen safety issues,
uncertainties related to product manufacturing, the lack of market acceptance
of our products, our inability to manage growth, the competitive environment in
relation to our business area and markets, our inability to attract and retain
suitably qualified personnel, the unenforceability or lack of protection of our
patents and proprietary rights, our relationships with affiliated entities,
changes and developments in technology which may render our products obsolete,
and other factors. For a further discussion of these risks, please refer to the
risk management sections in Genmab’s most recent financial reports, which are
available on www.genmab.com. Genmab does not undertake any obligation to update
or revise forward looking statements in this Company Announcement nor to
confirm such statements in relation to actual results, unless required by law.

Genmab®; the Y-shaped Genmab logo®; HuMax®; HuMax-CD20®; HuMax®-EGFr;
HuMax®-IL8; HuMax®-TAC; HuMax®-CD38; HuMax®-TF; HuMax®-Her2; HuMax®-cMet,
HuMax®-CD74, DuoBody™ and UniBody® are all trademarks of Genmab A/S. Arzerra®
is a trademark of GlaxoSmithKline.

Company Announcement no. 01
CVR no. 2102 3884

Genmab A/S
Bredgade 34
1260 Copenhagen K
Denmark