Exhibit 99.1


FOR IMMEDIATE RELEASE

               GENOME THERAPEUTICS RECEIVES MILESTONE PAYMENT FROM
                WYETH-AYERST FOR SIGNIFICANT RESEARCH ADVANCES IN
                              OSTEOPOROSIS PROGRAM

WALTHAM, MASS., JUNE 18, 2001 - Genome Therapeutics Corp. (Nasdaq: GENE)
announced today the receipt of milestone payments from Wyeth-Ayerst, the
pharmaceutical division of American Home Products (NYSE: AHP), for the
completion of a major advancement in their genomics-based alliance to develop
novel therapeutics for the prevention and treatment of osteoporosis. A joint
publication describing the scientific discoveries supporting this milestone is
planned.

"Our success represents the benefits of our collaborations with a leader in
women's health, Wyeth-Ayerst and the premier bone mineral geneticists at
Creighton University," commented Steven M. Rauscher, CEO and President, Genome
Therapeutics. "Attaining these research milestones in our alliance with
Wyeth-Ayerst helps validate our proven research approach in chronic human
diseases."

The advancement is the result of a multi-year alliance between Wyeth-Ayerst and
Genome Therapeutics, building on research previously conducted with the
Creighton University Osteoporosis Research Center. Genome Therapeutics gained
access to a unique family of individuals exhibiting a high bone mass trait from
Creighton University in 1997, providing a potential shortcut to the
identification of novel genes and targets for new product development in
osteoporosis.

"This milestone is a major advance in our efforts to harness genomics for the
development of therapies with potential to prevent or treat osteoporosis," said
Robert Ruffalo, Ph.D., Executive Vice-President, Research and Development, at
Wyeth-Ayerst Research. "We are pleased with the rapid pace of discovery in this
alliance with Genome Therapeutics."

Osteoporosis, an increasingly prevalent disease, is characterized by low bone
mass, structural deterioration of bone tissue and an increased susceptibility to
fractures. If not treated, the disease progresses with the hip and spine
becoming increasingly vulnerable. According to the National Institutes of
Health, osteoporosis is a complex disease that affects over 10 million people in
the United States at a direct cost of $14 billion. It can result in 1.5 million
fractures every year. One out of two women and one in eight men over 50 years
old will have an osteoporosis-related fracture in their lifetime.

Genome Therapeutics and Wyeth-Ayerst entered into a research collaboration in
December 1999 to discover new therapeutics for the prevention and treatment of
osteoporosis. The agreement included an up-front license fee, funding for a
multi-year research program, milestone payments and future royalties on sales of
products developed as a result of this collaboration. If the research goals of
the alliance are met, total payments to Genome Therapeutics could exceed $118
million, excluding royalties.

Genome Therapeutics (www.genomecorp.com) is a genomics-based drug discovery
company operating two lines of business: genomics services and
biopharmaceutical. The genomics services business focuses on services that
enable other organizations to achieve their drug discovery objectives and
includes the GTC Sequencing Center and the PathoGenome(TM) Database. The
biopharmaceutical business focuses on the development of novel therapeutics,
vaccines and diagnostics to solve major medical needs, includes six alliances
with pharmaceutical companies (Schering-Plough, AstraZeneca, Wyeth-Ayerst and
bioMerieux) and a joint venture with ArQule.


STATEMENTS IN THIS PRESS RELEASE THAT ARE NOT STRICTLY HISTORICAL ARE "FORWARD
LOOKING" STATEMENTS AS DEFINED IN THE PRIVATE SECURITIES LITIGATION REFORM ACT
OF 1995. A NUMBER OF IMPORTANT FACTORS COULD CAUSE ACTUAL


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RESULTS TO DIFFER MATERIALLY FROM THOSE PROJECTED OR SUGGESTED IN THE FORWARD
LOOKING STATEMENT, INCLUDING, BUT NOT LIMITED TO, THE ABILITY OF THE COMPANY AND
ITS ALLIANCE PARTNERS TO (I) SUCCESSFULLY DEVELOP PRODUCTS BASED ON THE
COMPANY'S GENOMIC INFORMATION, (II) OBTAIN THE NECESSARY GOVERNMENTAL APPROVALS,
(III) EFFECTIVELY COMMERCIALIZE ANY PRODUCTS DEVELOPED BEFORE ITS COMPETITORS
AND (IV) OBTAIN AND ENFORCE INTELLECTUAL PROPERTY RIGHTS, AS WELL AS THE RISK
FACTORS DESCRIBED IN EXHIBIT 99 OF THE COMPANY'S ANNUAL REPORT ON FORM 10-K FOR
THE FISCAL YEAR ENDED AUGUST 31, 2000 AND FROM TIME TO TIME IN THE COMPANY'S
OTHER REPORTS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION.

                                      *****

With this event, Genome Therapeutics Management has revised expectations for the
year ended August 31, 2001:

    -- Revenues are projected to be in the range of $32-36 million
    -- Total costs and expenses are projected to be in the range of $39-42
       million



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