PROSPECTUS

Filed pursuant to Rule 424(b)(4) of the Securities Act of 1933
Registration No. 333-65701

7,071,810 Shares

LEUKOSITE, INC.
Common Stock

Selling stockholders identified in this prospectus may sell up to 7,071,810
shares of common stock of LeukoSite, Inc. LeukoSite will not receive any of the
proceeds from the sale of shares by the selling stockholders. LeukoSite's common
stock is listed on the Nasdaq National Market under the symbol "LKST". On
October 28, 1998, the closing sale price of the common stock, as reported on
the Nasdaq National Market, was $8.00 per share.

Investing in the common stock involves a high
degree of risk. See "Risk Factors,"
beginning on page 3.

Neither the Securities and Exchange Commission nor any state
securities commission has approved or disapproved of these securities, or
determined if this prospectus is truthful or complete. Any representation to
the contrary is a criminal offense.

The selling stockholders may sell the shares of common stock described in
this prospectus in public or private transactions, on or off the National Market
System of the Nasdaq Stock Market, at prevailing market prices, or at privately
negotiated prices. The selling stockholders may sell shares directly to
purchasers or through brokers or dealers. Brokers or dealers may receive
compensation in the form of discounts, concessions or commissions from the
selling stockholders. More information is provided in the section titled "Plan
of Distribution."

The date of this prospectus is November 2, 1998.

WHERE YOU CAN GET MORE INFORMATION

We are a reporting company and file annual, quarterly and current reports,
proxy statements and other information with the SEC. You may read and copy these
reports, proxy statements and other information at the SEC's public reference
rooms in Washington, DC, New York, NY and Chicago, IL. You can request copies of
these documents by writing to the SEC and paying a fee for the copying cost.
Please call the SEC at 1-800-SEC-0330 for more information about the operation
of the public reference rooms. Our SEC filings are also available at the SEC's
Web site at "http://www.sec.gov". In addition, you can read and copy our SEC
filings at the office of the National Association of Securities Dealers, Inc. at
1735 K Street, Washington, DC 20006.

The SEC allows us to "incorporate by reference" information that we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information incorporated by reference is
an important part of this prospectus, and information that we file later with
the SEC will automatically update and supersede this information. We incorporate
by reference the documents listed below and any future filings we will make with
the SEC under Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act
of 1934:

- Annual Report on Form 10-K for the year ended December 31, 1997;

- Quarterly Reports on Form 10-Q for the quarters ended March 31, 1998
and June 30, 1998;

- Current Report on Form 8-K filed January 26,
1998; and

- The description of the common stock contained in LeukoSite's
Registration Statement on Form 8-A filed with the SEC under the
Securities Exchange Act of 1934.

You may request a copy of these filings at no cost, by writing, telephoning
or e-mailing us at the following address:

LeukoSite, Inc.
215 First Street
Cambridge, MA 02142
Attn: Investor Relations
(617) 621-9350
information@LeukoSite.com

This prospectus is part of a Registration Statement we filed with the SEC.
You should rely only on the information incorporated by reference or provided in
this prospectus. We have not authorized anyone else to provide you with
different information. We are not making an offer of these securities in any
state where the offer is not permitted. You should not assume that the
information in this prospectus is accurate as of any date other than the date on
the front of the document.

FORWARD-LOOKING STATEMENTS

This prospectus contains forward-looking statements within the meaning
of Section 27A of the Securities Act of 1933 and Section 21E of the
Securities Exchange Act of 1934, including statements regarding LeukoSite's
drug development programs, clinical trials, receipt of regulatory approval,
capital needs, intellectual property, expectations and intentions.
Forward-looking statements necessarily involve risks and uncertainties, and
LeukoSite's actual results could differ materially from those anticipated in
the forward-looking statements due to a number of factors, including those
set forth below under "Risk Factors" and elsewhere in this prospectus. The
factors set forth below under "Risk Factors" and other cautionary statements
made in this prospectus should be read and understood as being applicable to
all related forward-looking statements wherever they appear in this
prospectus.

RISK FACTORS

Investing in LeukoSite's common stock is very risky. You should be able to
bear a complete loss of your investment. You should carefully consider the
following factors, in addition to the other information in this prospectus.

Uncertainty of Clinical Trial Outcomes. Three of our monoclonal antibody
drug candidates, LDP-01, LDP-02 and LDP-03 (also known as CAMPATH), are
currently being tested in human clinical trials. Clinical trials of drug
candidates involve the testing of potential therapeutic agents in humans to
determine the safety and efficacy of drug candidates. Many drugs in human
clinical trials fail to demonstrate desired safety and efficacy characteristics.
Drugs in later stages of development may fail despite having progressed through
initial human testing. We cannot assure you that the clinical trials of any of
our drug candidates will be successful. If we were unable to successfully
complete the clinical trials of any of our drug candidates, it could have a
material adverse effect on our business, financial condition and results of
operations.

Early Stage Product Development Programs. Many of our research and
development programs are at an early stage. We have not completed clinical
development of any of our monoclonal antibody products or selected any of our
small molecule drug candidates for clinical development. Any drug candidates
that we develop will require significant additional research and development
efforts, extensive preclinical (animal and laboratory) and clinical testing, as
well as regulatory approval. In addition, encouraging results obtained in
laboratory testing alone do not necessarily mean that similar results will be
obtained in later stages of preclinical development or in human clinical
testing. Potential drug candidates are subject to inherent risks of failure.
These risks include the possibilities that no drug candidate will be found safe
or effective, meet applicable regulatory standards, or receive the necessary
regulatory clearances.

We cannot assure you that any drug candidates will be developed into
commercially successful drugs. There may be delays in receipt of regulatory
approvals. The drugs could be uneconomical to manufacture or produce on a large
scale. We could be unable to successfully market the new drugs or achieve
customer acceptance. The proprietary rights of others could stop us from being
able to market the drugs, or third parties could market superior or equivalent
drugs

If we were unable to develop safe, commercially viable drugs, it would have
a material adverse effect on our business, financial condition and results of
operations.

Dependence on Collaborative Partners. A key element of our strategy
is to accelerate drug discovery and development programs and to fund capital
requirements, in part, by entering into collaboration agreements with major
pharmaceutical companies. We have entered into collaboration agreements with
Warner-Lambert Company, Roche Bioscience, Kyowa Hakko Kogyo, Ltd. and
Genentech, Inc. Under our collaboration agreements with Warner-Lambert, Roche
Bioscience and Kyowa, our collaborative partners have the right, but not the
obligation, to conduct preclinical and clinical trials of compounds developed
during our collaboration and to develop and commercialize any drug
candidates. Under the Genentech collaboration agreement, Genentech has the
right, but not the obligation, to conduct

Phase III clinical trials of our LDP-02 monoclonal antibody product. Our
receipt of revenues from milestones, royalties, co-promotion rights or
profit-sharing under the collaboration agreements is dependent upon the
activities and the development, manufacturing and marketing resources of our
collaborative partners. Our collaborative partners have significant
discretion in electing whether to pursue the development of any potential
drug candidates. As a result, we cannot control the amount and timing of
resources dedicated by our collaborative partners to our collaborations.

We cannot assure you that our collaborative partners will pursue the
development and commercialization of compounds resulting from our collaboration
or that we will successfully derive any revenue from the sales of drugs. Certain
drug candidates discovered by us may be competitive with our collaborative
partners' drugs or drug candidates. Accordingly, we cannot assure you that our
collaborative partners will proceed with the development of our drug candidates
or that they will not pursue their existing or alternative technologies in
preference to our drug candidates. Disagreements between us and our
collaborative partners could lead to delays in research or in the development
and commercialization of certain drug candidates or in litigation. Any of these
factors could have a material adverse effect on our business, financial
condition and results of operations.

We are relying on our collaborative partners to fund a significant portion
of our research operations and clinical trials over the next several years.
Although each of the collaboration agreements may be extended past its current
term, we cannot assure you that these contracts will be extended or renewed.
Each of the collaboration agreements is terminable by either party upon breach
by the other party. Moreover, Warner-Lambert may terminate its collaboration
agreements upon six months written notice. Kyowa may terminate its collaboration
agreement by giving 60 days written notice. Genentech may terminate its
collaboration agreement after December 1998, upon nine months written notice. We
cannot assure you that any of the collaboration agreements will remain in effect
for its expected term. The delay or termination of a collaboration agreement
could force us to undertake unforeseen additional responsibilities or to devote
unbudgeted additional resources to development or commercialization of a drug
candidate. Those events could have a material adverse effect on our business,
financial condition and results of operations.

History of Losses and Expectation of Future Losses; Uncertainty of Future
Profitability. LeukoSite was incorporated in May 1992 and has incurred a net
operating loss every year. Our accumulated deficit was approximately $ 39.6
million through June 30, 1998. We expect to incur significant additional
operating losses over the next several years due to expanded research and
development efforts, preclinical and clinical trials and the funding of
development activities under the joint venture with Ilex Oncology, Inc.

In the next few years, we expect our revenues to be limited to any research
support and milestone payments under the current collaboration agreements and
any future collaboration agreements that we may establish. We cannot assure you
that we will achieve the milestones that are required to receive additional
funds from our current collaborative partners or that we will be able to
maintain the collaboration agreements in effect. In addition, we can not assure
you that we will be able to establish any additional collaborative relationships
on acceptable terms, if at all. We cannot assure you that LeukoSite will operate
profitably.

Substantial Additional Financing Requirements; Uncertainty of Available
Funding. We will require substantial additional funds in order to finance our
drug discovery and development programs, fund operating expenses, pursue
regulatory clearances, develop manufacturing, marketing and sales capabilities,
and prosecute and defend our intellectual property rights. We depend upon our
collaborative partners for research and clinical trials funding. We cannot give
any assurance that funding will continue under our existing collaboration
agreements, or that existing and potential collaboration agreements will be
sufficient to fund our operating expenses.

We intend to seek additional funding through public or private financing or
through collaboration arrangements with collaborative partners. If we raise
funds by selling equity securities, sales may dilute

your share ownership and future investors may be granted rights superior to
yours. We cannot give any assurance, however, that additional financing will
be available on acceptable terms, if at all.

Impact of Extensive Government Regulation. The LeukoSite products under
development are subject to regulation by the federal government, including
the Food and Drug Administration, and by state and local governments. If our
products are marketed abroad, they will also be subject to export
requirements and to regulation by foreign governments. The applicable
regulatory approval process is lengthy and expensive and must be completed
prior to the commercialization of a product. We cannot give any assurance
that we will be able to obtain necessary regulatory approvals on a timely
basis, if at all, for any of our products under development. Delays in
receipt or failure to receive such approvals or failure to comply with
existing or future regulatory requirements could have a material adverse
effect on our business, financial condition and results of operations.

Product development and approval to meet FDA regulatory requirements takes
a number of years, involves the expenditure of substantial resources and is
uncertain. Many products that initially appear promising ultimately do not reach
the market because they are not found to be safe or effective. In addition, the
current regulatory framework could change and additional regulations may arise
at any stage of product development that may affect approval, delay the
submission or review of an application or require additional expenditures.

We cannot be certain if and when we or our collaborative partners will
submit any marketing applications for any of our product candidates for any
indications. We cannot provide any assurance that any clinical studies will be
completed or, if completed, will demonstrate that the products are safe and
effective. We cannot provide any assurance that required approvals will be
granted by FDA on a timely basis, or at all, for any of these products for any
indications.

All of our product candidates will require FDA and foreign government
approvals for commercialization. As yet, no approvals have been obtained to
market any drug. We have completed patient enrollment in our licensing trial of
CAMPATH (also known as LDP-03) but have not completed analysis of the results of
the trial. We cannot be certain as to the clinical efficacy and safety
characteristics of CAMPATH at this time. We have commenced clinical trials of
our LDP-01 and LDP-02 product candidates in the United Kingdom and intend to
continue to perform preclinical and clinical trials in the United Kingdom,
subject to receipt of required U.K. regulatory approvals. FDA may require us to
repeat certain or all U.K. clinical trials in order to receive approval to
market the drugs in the United States, which would increase the time and expense
required to obtain FDA approval.

The effect of government regulation may be to delay marketing of our
products for a considerable or indefinite time, impose costly procedural
requirements and furnish a competitive advantage to larger companies or
companies more experienced in regulatory affairs. Delays in obtaining
governmental regulatory approval could adversely affect our marketing strategy
as well as our ability to generate revenue from product sales. The failure to
obtain marketing approval of our products on a timely basis, or at all, would
have a material adverse effect on our business, financial condition and results
of operations.

Uncertainties Relating to Patents and Proprietary Rights. Our success will
depend in part on our ability to obtain United States and foreign patent
protection for our drug candidates and processes, preserve our trade secrets,
and operate without infringing the proprietary rights of third parties. We place
considerable importance on obtaining patent protection for significant new
technologies, products and processes. Legal standards relating to the validity
of patents covering pharmaceutical and biotechnological inventions and the scope
of claims made under such patents are still developing. Our patent position is
highly uncertain and involves complex legal and factual questions. We cannot be
certain that the applicants or inventors of subject matter covered by patent
applications or patents owned by or licensed to us were the first to invent or
the first to file patent applications for such inventions. We cannot give any
assurance
5

that any patents will issue from any of the pending or future patent
applications we own or have licensed. Existing or future patents owned by or
licensed to us may be challenged, infringed upon, invalidated, found to be
unenforceable or circumvented by others. Further, we cannot give any assurance
that any rights we may have under any issued patents will provide us with
sufficient protection against competitive products or otherwise cover
commercially valuable products or processes.

If another party claims the same subject matter or subject matter
overlapping with subject matter that we have claimed in a United States patent
application or patent, we may decide or be required to participate in
interference proceedings in the United States Patent and Trademark Office in
order to determine priority of invention. Losing an interference proceeding
would deprive us of patent protection sought or previously obtained.
Participation in such proceedings could result in substantial costs, whether or
not the eventual outcome is favorable.

In addition to patent protection, we rely on trade secrets, proprietary
know-how, and confidentiality provisions in agreements with our collaborative
partners, employees and consultants to protect our intellectual property. We
also rely on invention assignment provisions in agreements with employees and
certain consultants. We cannot give any assurance that these agreements will
not be breached or that we would have adequate remedies for any such breach.
We cannot give any assurance that our trade secrets, proprietary know-how and
intellectual property will not become known or be independently discovered by
others.

Our product candidates, LDP-01, LDP-02 and LDP-03 (CAMPATH), are
humanized monoclonal antibodies. We are aware that patents have been issued
in the United States and abroad to third parties that relate to certain
humanized antibodies, products useful for making humanized antibodies, and
processes for making and using humanized antibodies. We may choose to seek or
be required to seek licenses under certain of these patents. We cannot give
any assurance that we will be able to obtain those licenses on acceptable
terms, or at all. In such event, the development, manufacture and sale of our
product candidates or products could be severely restricted or prohibited.

We are also aware of other third party applications in the United States
and abroad relating to certain humanized monoclonal antibodies, products useful
for making humanized antibodies, and processes for making and using humanized
antibodies. We may choose to seek or be required to seek licenses under some or
all of the patents which might issue from these patent applications. We cannot
give any assurance that we will be able to obtain those licenses on acceptable
terms, or at all. In such event, the development, manufacture and sale of our
drug candidates or products could be severely restricted or prohibited.

Litigation in the pharmaceutical and biotechnology industry regarding
patents and other proprietary rights has been significant and widespread.
Litigation or other proceedings may be necessary to assert claims of
infringement, to enforce patents owned by or licensed to us, to protect trade
secrets, know-how or other intellectual property rights owned by or licensed to
us, or to determine the scope or validity of proprietary rights of third parties
and defend against claims of infringement thereof. There can be no assurance
that any of the patents owned by or licensed to us will ultimately be held valid
or that efforts to assert or defend any patents, trade secrets, know-how or
other intellectual property rights would be successful. Similarly, there can be
no assurance that the products or processes we use will not be held to infringe
patents or other intellectual property rights of others. The expenses of
intellectual property litigation or other proceedings are likely to be
substantial, and could have a material adverse effect on our business, operating
results and financial condition. An adverse outcome in litigation or a
proceeding could subject us to significant liabilities or require us to cease
certain activities. If any of our present or future products or processes is
alleged or determined to infringe upon the patents or impermissibly use the
intellectual property of others, we may choose or be required to obtain licenses
from third parties under their patents or proprietary rights. We cannot give any
assurance that we will be able to obtain those licenses on acceptable terms, or
at all. In such event, the development, manufacture and sale of our drug
candidates or products could be severely restricted or prohibited.

Intense Competition. The biotechnology and pharmaceutical industries are
intensely competitive. We have numerous competitors in the United States and
elsewhere. Our competitors include major, multinational pharmaceutical and
chemical companies, specialized biotechnology firms and universities and
other research institutions. Many of these competitors have greater financial
and other resources, larger research and development staffs and more
effective marketing and manufacturing organizations,

than we do. In addition, academic and government institutions have become
increasingly aware of the commercial value of their research findings. These
institutions are now more likely to enter into exclusive licensing agreements
with commercial enterprises, including our competitors, to market commercial
products.

We cannot give any assurance that our competitors will not succeed in
developing or licensing technologies and drugs that are more effective or
less costly than any we are developing. Our competitors may succeed in
obtaining FDA or other regulatory approvals for drug candidates before we do.
We cannot give any assurance that drugs resulting from our research and
development efforts, if approved for sale, will be able to compete
successfully with our competitors' existing products or products under
development.

Rapid Technological Change. Biotechnology and related pharmaceutical
technology have undergone and are subject to rapid and significant change. We
expect that the technologies associated with biotechnology research and
development will continue to develop rapidly. Our future will depend in large
part on our ability to maintain a competitive position with respect to these
technologies. Any compounds, products or processes that we develop may become
obsolete before we recover any expenses incurred in connection with
developing those products.

Reliance on Contract Manufacturers; Lack of Manufacturing Experience. We
are dependent on other people for the manufacture of our product candidates. We
are aware of only a limited number of manufacturers who we believe have the
ability and capacity to manufacture our drug candidates for preclinical and
clinical trials. We have entered into an agreement with Dr. Karl Thomae, GmbH, a
contract manufacturer, for the production of CAMPATH (LDP-03) for clinical
trials. We have been relying on the Therapeutic Antibody Centre for the
manufacture of LDP-01 and LDP-02 for preclinical testing. We intend to employ
the manufacturing capability of the Therapeutic Antibody Centre through other
early clinical trials. If we were required to transfer manufacturing processes
to other manufacturers, we could experience significant delays in supply. If, at
any time, we were unable to maintain, develop or contract for manufacturing
capabilities on acceptable terms, our ability to conduct preclinical and
clinical trials will be adversely affected and there would be delays in the
submission of drug candidates for regulatory approvals.

Our collaborative partners generally have the exclusive right to
manufacture products resulting from our collaborations. We have no experience in
manufacturing and currently lack the facilities and personnel to manufacture
products in accordance with Good Manufacturing Practices as prescribed by the
FDA or to produce an adequate supply of compounds to meet future requirements.

Risks Associated with Ilex Joint Venture. We have entered into a joint
venture with Ilex for the development and commercialization of CAMPATH
(LDP-03) for the treatment of chronic lymphocytic leukemia. As part of the
joint venture, we are obligated to share fifty percent of the development
costs of CAMPATH. We cannot give any assurance that we will have the cash
available or will desire to maintain our commitment to the joint venture. In
the event that we fail for any reason to make a required capital contribution
to the joint venture, Ilex may gain control of the management of the joint
venture and become entitled to a greater share of the profits derived from
product sales of CAMPATH.

We can also give no assurance that Ilex will have the cash available or
will desire to maintain its commitment to the joint venture. In the event that
Ilex fails for any reason to make a required capital contribution to the joint
venture, we may be required to make additional capital contributions to the
joint venture to maintain the desired level of development activities by the
joint venture. We can give no assurance that we will be able to compensate for
any failure by Ilex to make any capital contribution or that the joint venture
would be able to continue operations with lesser funding. In addition, after the
earlier of a change in control of Ilex or LeukoSite or October 2, 2000, either
company has the right to purchase the other company's ownership of the joint
venture in the event of an unresolved deadlock. As a result, we can give no
assurance that we will be able to recoup our investment in the joint venture.

Dependence on Key Personnel. We believe that our ability to successfully
implement our business strategy is highly dependent on our management and
scientific team. None of our executive officers has entered into an employment
agreement. The loss of services of one or more of these individuals might hinder
the achievement of our development objectives. We are highly dependent on our
ability to hire and retain qualified scientific and technical personnel. The
competition for these employees is intense. We cannot give any assurance that we
will continue to be able to hire and retain the qualified personnel needed for
our business. Loss of the services of or the failure to recruit key scientific
and technical personnel could adversely affect our business, operating results
and financial condition.

Control by Existing Stockholders. LeukoSite's officers, directors and
principal stockholders own or control approximately 47.25% of the outstanding
common stock. As a result, these stockholders, acting together, will have the
ability to control most matters requiring approval by the stockholders.

Absence of Dividends. We have never declared or paid cash dividends. We do
not intend to declare or pay any cash dividends in the foreseeable future.

THE COMPANY

LeukoSite is a biotechnology company developing proprietary drugs designed
to block the disease-promoting action of white blood cells. The focus of
LeukoSite's research and development is on drugs for the treatment of cancer,
autoimmune and inflammatory diseases. The mailing address and telephone number
of our principal executive office is 215 First Street, Cambridge, MA 02142
(617) 631-9350.

RECENT DEVELOPMENTS

On July 1, 1998, LeukoSite raised approximately $11.8 million in a private
placement of common stock. LeukoSite issued approximately 1,970,000 shares of
common stock.

USE OF PROCEEDS

LeukoSite will not receive any proceeds from the sale of the shares of
common stock offered by the selling stockholders.

SELLING STOCKHOLDERS

Under a Registration Rights Agreement dated July 1, 1998 among LeukoSite
and certain selling stockholders, we agreed to register the LeukoSite common
stock sold to those selling stockholders in the private placement and to use our
best efforts to keep the Registration Statement effective for two years, or
until all of the shares are sold under the Registration Statement, whichever
comes first. Our registration of the shares of common stock does not necessarily
mean that the selling shareholders will sell all or any of the shares.

The following table sets forth certain information regarding the beneficial
ownership of the common stock as of September 30, 1998, by each of the selling
stockholders.

The information provided in the table below with respect to each selling
stockholder has been obtained from such selling stockholder. Except as otherwise
disclosed below, none of the selling stockholders has, or within the past three
years has had, any position, office or other material relationship with the
Company. Because the selling stockholders may sell all or some portion of the
shares of common stock beneficially owned by them, only an estimate (assuming
each selling stockholder sells all of its shares offered hereby) can be given as
to the number of shares of common stock that will be beneficially owned by the
selling stockholders after this offering. In addition, the selling stockholders
may have sold, transferred or otherwise disposed of, or may sell, transfer or
otherwise dispose of, at any time or from time to time since the date on which
they provided the information regarding the shares of common stock beneficially
owned by them, all or a portion of the shares of common stock beneficially owned
by them in transactions exempt from the registration requirements of the
Securities Act of 1933.

Shares
Beneficially Number
Owned Of Shares Shares
Prior to Offering Being Beneficially Owned
Name and Address of Beneficial Owner (1) Offered After Offering (1)
- ------------------------------------ ----------------- -------- -------------------
Number Percent

Entities Affiliated with HealthCare Ventures 2,482,343 2,479,093 3,250 *
LLC (2)
44 Nassau Street
Princeton, New Jersey 08542

Timothy Springer (3) 773,741 770,825 2,916 *
Center for Blood Research
200 Longwood Avenue
Boston, Massachusetts 02115

Entities Affiliated with Schroders PLC (4) 756,451 291,667 464,784 4.9
120 Cheapside
London EC2V 6DS
England

Warner-Lambert Company 618,466 618,466 -- *
201 Tabor Road
Morris Plains, New Jersey 07950

Roche Finance Ltd 610,301 610,301 -- *
c/o Hoffman-La Roche, Ltd.
124 Grensacherstrasse
CH-4002 Basel
Switzerland

Entities Affiliated with Rho Management
Co., Inc.(5) 548,307 548,307 -- *
767 Fifth Avenue
New York, New York 10153

Lombard Odier & Cie 425,325 425,325 -- *
Toedistrasse 36
CH8027
Zurich, Switzerland

Perseus Capital, LLC 416,667 416,667 -- *
The Army and Navy Club Building
1627 I Street NW
Suite 610
Washington, DC 20006

S.R. One Ltd 222,222 222,222 -- *
Bay Colony Executive Park, Suite 315
565 East Swedesford Road
Wayne, Pennsylvania 19087

Goldman Sachs & Co. 166,667 166,667 -- *
One New York Plaza
New York, New York 10004

Springer Family Trust 134,067 134,067 -- *
245 Walcott Road
Chestnut Hill, Massachusetts

Peretz Family Investments (6) 115,758 115,758 -- *
20 Larchwood Drive
Cambridge, MA 02138

New Day Investment Partnership 111,111 111,111 -- *
6690 LaJolla Scenic South
LaJolla, California 92037

Entities Affiliated with Weiss Peck & Greer LLC (7) 71,111 71,111 -- *
One New York Plaza
New York, New York 10004

YK Capital L.P. (8) 50,000 50,000 -- *
509 Rochampton Road
Hillsborough, California 94010

Four Partners 33,334 33,334 -- *
667 Madison Avenue
7th Floor
New York, New York 10021

Christopher Walsh (9) 10,898 945 9,953 *
Harvard Medical School
45 Shattuck Street
Boston, Massachusetts 02115

Daniel Kisner 5,444 5,444 -- *
1849 Montgomery Avenue
Cardiff, California 92007

Todd Noonan 500 500 -- *
International Creative
Management, Inc.
40 West 57th Street, 18th Floor
New York, New York 10019

* Less than 1% of the outstanding shares of common stock.

(1) Beneficial ownership is determined in accordance with Rule 13d-3(d)
promulgated by the Commission under the Securities Exchange Act of 1934, as
amended. Shares of common stock issuable pursuant to options, warrants and
convertible securities, to the extent such securities are currently
exercisable or convertible within 60 days of September 30, 1998, are
treated as outstanding for computing the percentage of the person holding
such securities but are not treated as outstanding for computing the
percentage of any other person. Unless otherwise noted, each person or
group identified possesses sole voting and investment power with respect to
shares, subject to community property laws where applicable. Shares not
outstanding but deemed beneficially owned by virtue of the right of a
person or group to acquire them within 60 days are treated as outstanding
only for purposes of determining the number of and percent owned by such
person or group.

(2) Includes shares held by HealthCare Ventures III, L.P., HealthCare Ventures
IV, L.P. and HealthCare Ventures V, L.P. Includes 3,250 shares of Common
Stock which HealthCare Ventures, LLC has the right to acquire within 60
days of September 30, 1998 upon the exercise of stock options. Mr. John
Littlechild, a director of the Company, is a general partner of the general
partner of HealthCare Ventures III, L.P., HealthCare Ventures IV, L.P. and
HealthCare Ventures V, L.P.

(3) Includes shares held by Dr. Springer's wife and the Springer Family Trust.
Dr. Springer disclaims beneficial ownership of all shares owned by his wife
and beneficial ownership of the shares owned by the Springer Family Trust
except to the extent of his proportional interest. Includes 2,916 shares
of Common Stock which Dr. Springer has the right to acquire within 60 days
of September 30, 1998 upon the exercise of stock options. Dr. Springer is
a director of the Company.

(4) Includes shares held by Schroder Ventures International Life Sciences Fund
L.P. 1, Schroder Ventures International Life Science Fund L.P. 2, Schroder
Ventures International Life Sciences Trust, Schroders Incorporated, and
Schroder Ventures International Life Sciences Fund Co-Investment Scheme.
Includes 3,250 shares of Common Stock which Schroders PLC has the right
to acquire within 60 days of September 30, 1998 upon the exercise of stock
options. Ms. Kate Bingham, a director of the Company, is a partner of
Schroders PLC.

(5) Includes shares held by Rho Management Trust II.

(6) Dr. Martin Peretz, a director of the Company, is a general partner of the
Peretz Family Investments.

(7) Includes shares held by WPG Life Sciences Fund, L.P. and WPG Institutional
Life Sciences, L.P.

(8) Dr. Yasunori Kaneko, a director of the Company, is a general partner of YK
Capital, L.P.

(9) Includes 4,468 shares of Common Stock which Dr. Walsh has the right to
acquire within 60 days of September 30, 1998 upon the exercise of stock
options. Dr. Walsh is a director of the Company.

PLAN OF DISTRIBUTION

The shares of common stock may be sold from time to time by the selling
stockholders in one or more transactions at fixed prices, at market prices at
the time of sale, at varying prices determined at the time of sale or at
negotiated prices. The selling stockholders may offer their shares of common
stock in one or more of the following transactions:

o on any national securities exchange or quotation service on
which the common stock may be listed or quoted at the time of
sale, including the Nasdaq National Stock Market,
o in the over-the-counter market,
o in private transactions,
o through options,
o by pledge to secure debts and other obligations, or
o a combination of any of the above transactions.

If required, we will distribute a supplement to this prospectus to
describe material changes in the terms of the offering.

The shares of common stock described in this prospectus may be sold
from time to time directly by the selling stockholders. Alternatively, the
selling stockholders may from time to time offer shares of common stock to or
through underwriters, broker/dealers or agents. The selling stockholders and any
underwriters, broker/dealers or agents that participate in the distribution of
the shares of common stock may be deemed to be "underwriters" within the meaning
of the Securities Act of 1933. Any profits on the resale of shares of common
stock and any compensation received by any underwriter, broker/dealer or agent
may be deemed to be underwriting discounts and commissions under the Securities
Act of 1933.

Any shares covered by this prospectus which qualify for sale pursuant
to Rule 144 under the Securities Act of 1933 may be sold under Rule 144 rather
than pursuant to this prospectus. The selling stockholders may not sell all of
the shares. The selling stockholders may transfer, devise or gift such shares by
other means not described in this prospectus.

To comply with the securities laws of certain jurisdictions the common
stock must be offered or sold only through registered or licensed brokers or
dealers. In addition, in certain jurisdictions, the common stock may not be
offered or sold unless they have been registered or qualified for sale or an
exemption is available and complied with.

Under the Securities Exchange Act of 1934, any person engaged in a
distribution of the common stock may not simultaneously engage in market-making
activities with respect to the common stock for nine business days prior to the
start of the distribution. In addition, each selling stockholder and any other
person participating in a distribution will be subject to the Securities
Exchange Act of 1934 which may limit the timing of purchases and sales of common
stock by the selling stockholders or any such other person. These factors may
affect the marketability of the common stock and the ability of brokers or
dealers to engage in market-making activities.

All expenses of this registration will be paid by LeukoSite. These
expenses include the SEC's filing fees and fees under state securities or "blue
sky" laws. The selling stockholders will pay all underwriting discounts and
selling commissions, if any.

LEGAL MATTERS

Bingham Dana LLP, Boston, Massachusetts will give its opinion that the
shares offered in this prospectus have been validly issued and are fully paid
and non-assessable. Justin P. Morreale, a partner at Bingham Dana LLP, is the
Secretary of LeukoSite. Other partners and associates at Bingham Dana LLP own a
total of approximately 1,600 shares of common stock.

EXPERTS

The consolidated financial statements of LeukoSite as of and for the
year ended December 31, 1997, incorporated by reference into this prospectus and
this Registration Statement, have been audited by Arthur Andersen LLP,
independent public accountants, as indicated in their report with respect
thereto, and are included herein in reliance upon the authority of said firm as
experts as giving said report.

We have not authorized any dealer, salesperson or other person to give any
information or to make any representations not contained in this prospectus
or any Prospectus Supplement. You must not rely on any unauthorized
information. This prospectus is not an offer of these securities in any state
where an offer is not permitted. The information in this prospectus is
current as of November 2, 1998. You should not assume that this prospectus is
accurate as of any other date.

Table of Contents

Page
----

Where You Can Get More
Information .................. 2

Forward-looking Statements ..... 3

Risk Factors ................... 3

The Company .................... 9

Recent Developments ............ 9

Use of Proceeds ................ 9

Selling Stockholders ........... 10

Plan of Distribution ........... 13

Legal Matters .................. 13

Experts ....................... 14

7,071,810 Shares

LeukoSite, Inc.

Common Stock

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PROSPECTUS

November 2, 1998

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