BB BIOTECH: Positive performance in the third quarter 2009

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Quarterly Report as at September 30, 2009

During the third quarter 2009, BB BIOTECH's portfolio companies
achieved a positive performance in line with the broad biotechnology
index, with the Net Asset Value (NAV) increasing by 7.2% in CHF. BB
BIOTECH's share price closed the quarter at CHF 77.95, up 12.2%
compared to the second quarter 2009. In Germany, it closed at EUR
51.42, up 10.6% compared to the previous quarter. The difference
between the share price and the Net Asset Value of BB BIOTECH
decreased at the end of the third quarter to 19.2% down from 22.8% at
the end of second quarter. We will continue our measures to control
the discount between the share price and Net Asset Value and as such
we have initiated the sixth share buyback program in September.

BB BIOTECH's core positions, Actelion, Celgene, Gilead and Vertex,
progressed in line with our assumptions. Actelion delivered continued
strong growth of its PAH franchise with the US FDA broadening the
Tracleer label to include treatment for less advanced PAH patients.
Clinical data for Almorexant, a potential new therapy for insomnia,
is the key milestone for the company by year end.

Celgene announced that a Phase III trial testing its flagship
product, Revlimid, for the treatment of patients with newly diagnosed
multiple myeloma ineligible for stem cell transplantation, was
stopped early as it met its primary efficacy end point at the first
interim analysis. The positive results should allow Celgene to expand
the label for Revlimid, currently approved only for
relapsed/refractory multiple myeloma patients, to the first-line
setting, increasing the sales potential for Revlimid.

Gilead reported positive earnings numbers, driven by continued
strength of its HIV products Atripla and Truvada. The company
announced a collaboration with Johnson & Johnson (Tibotec) to develop
a fixed-dose combination of Truvada with Tibotec's non-nucleoside
reverse transcriptase inhibitor (NNRTI) TMC278. We believe this has
the potential to replace Sustiva, the NNRTI component of Atripla. A
successful launch could solidify Gilead's leading position in HIV
therapy and could boost Gilead's earnings.

At the American Association for the Study of Liver Disease meeting in
November, we expect Vertex to present results from a Phase II trial
with Telaprevir, its protease inhibitor for HCV. The study is
comparing twice-daily dosing to three-times-daily dosing (already
shown to be highly effective in Phase II trials) and we expect the
cure rate between the two regimens to be comparable, providing a
further advantage to patients. We also expect data on several early
stage protease inhibitors in development from competitor companies.
While one or more of these agents could be successful in the clinic,
we believe the safety hurdle is high and they would come to market
several years behind Telaprevir, which we expect to launch in 2011.

BB BIOTECH has initiated two new investment positions with Genzyme
and Micromet. Genzyme is progressing well to resolve its
manufacturing problems for its key product Cerezyme, approved for the
treatment of a rare genetic lysosomal storage disorder called
Gaucher's Disease. BB BIOTECH participated in the capital increase of
Micromet. Micromet's lead clinical program is a bi-specific
single-chain antibody targeting CD19 BiTE® for the treatment of
lymphoma. Positive clinical data support the bi-specific antibody
platform of Micromet. The positions in Rigel and The Medicines
Company were sold, with
BB BIOTECH realizing a significant gain on The Medicines Company of
around CHF 109 mn over the entire investment period.

BB BIOTECH initiated its sixth share buyback program on September 16,
2009, acquiring 113 500 shares until the end of the third quarter.
The shareholders confirmed the resolution of a sixth share buyback
program at the extraordinary general assembly on July 6, 2009 to
repurchase and cancel up to 1.8225 million of BB BIOTECH's registered
shares, corresponding to 10% of total share capital. The reduction in
the number of outstanding registered shares will increase earnings
per share and should also reduce the discount between the market
price and the reported Net Asset Value.

The ongoing debate on US healthcare reform is advancing with the
uncertainty still weighing on the share performance of many
healthcare companies. We think BB BIOTECH's portfolio is well
balanced regarding possible healthcare reform risks towards potential
changes to the portfolio companies' revenues and profits. Innovative
and effective medicines will continue to achieve good pricing as well
as reimbursement in the Western world, even in a cost conscious
environment.

This is the composition of BB BIOTECH's Portfolio as at September 30,
2009 (in % of securities, rounded values):

CORE HOLDINGS
Actelion 32.1%
Gilead 17.6%
Celgene 16.4%
Vertex Pharmaceuticals 12.2%

SMALL PARTICIPATIONS
Novo Nordisk 4.2%
Zymogenetics 2.4%
Biogen Idec 2.2%
Roche Holding 1.9%
Arena Pharmaceuticals 1.6%
Basilea Pharmaceutica 1.4%
Affymetrix 1.2%
Genzyme 1.2%
Micromet 1.0%
Optimer Pharmaceuticals 0.8%
Elan 0.7%
NicOx 0.4%
Incyte 0.4%
Epigenomics 0.3%
BioXell 0.2%
Keryx Biopharmaceuticals 0.1%
Clinuvel <0.1%
3% Convertible Bond Deutsche Bank (-18.05.2012)* 0.2%

Biogen Idec call option (short) <(0.1%)
Basilea put option (short) <(0.1%)
USD/CHF put option (long) as 1.3%
USD/CHF call option (short) <(0.1%)
SWAP agreement on treasury shares 0.1%

Total securities CHF 1 539.5 mn

Liquid funds (net) CHF 52.8 mn
Other assets CHF 18.7 mn
Other payables CHF (3.5) mn

Total shareholder's equity CHF 1 607.5 mn
Treasury shares (in % of company) 8.6%

* Convertible into registered shares BB BIOTECH AG
The Quarterly Report as at September 30, 2009 is available on
www.bbbiotech.com

For further information please contact:
Bellevue Asset Management AG, Seestrasse 16, CH-8700 Kusnacht,
Switzerland
Nafida Bendali or Maria-Grazia Iten-Alderuccio, Tel. +41 44 267 67 00

Company profile:
BB BIOTECH acquires holdings in companies in the biotechnology growth
market and is currently one of the world's largest investors in the
sector. BB BIOTECH is listed in Switzerland, in Germany and in Italy.
The focus of the holdings is on quoted companies that are
concentrating on the development and marketing of innovative
medicines. For the selection of holdings, BB BIOTECH relies on
fundamental analysis by physicians and molecular biologists. The
Board of Directors has many years of industrial and scientific
experience.

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BB BIOTECH AG
Vordergasse 3 Schaffhausen Switzerland

WKN: AONFN3;
ISIN: CH0038389992; Index: SBIOM, IGSP, SLIFE;
Listed: Investment Companies in SIX Swiss Exchange;
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