Document:

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                                                                 Exhibit 10.26.2

                          SECOND AMENDMENT TO SUBLEASE

      This Second Amendment to Sublease, dated as of December 18, 2003 (this
"Second Amendment"), is by and between ARIAD Corporation, a Delaware corporation
("Sublandlord"), with a place of business at 26 Landsdowne Street, Cambridge,
Massachusetts 02139, and ViaCell, Inc., a Delaware corporation ("Subtenant")
with an address of 131 Clarendon Street, 3rd Floor, Boston, MA 02116

                              PRELIMINARY STATEMENT

      By Lease dated January 8, 1992 ("Original Lease"), ARIAD Pharmaceuticals,
Inc. leased from Forest City Cambridge, Inc. ("Prime Landlord") approximately
100,361 rentable square feet of space in the building known as The Jackson
Building, having a street address of 26 Landsdowne Street, Cambridge,
Massachusetts ("Building"). The Prime Lease Premises (defined herein).

      ARIAD Pharmaceuticals, Inc. assigned its interest in the Original Lease to
Sublandlord, which assignment was executed on October 19, 1992, and recorded
with the Middlesex County Southern District Registry of Deeds in Book 22527,
Page 381, and filed with the Middlesex County Southern Registry District of the
Land Court as Document No. 888025 noted on Certificate of Title No. 157415.

      The Original Lease as amended by the First and the Second Amendment to
Lease, each dated May 12, 1994, the Third Amendment to Lease, dated June 1,
1994, a letter agreement dated December 16, 1996 (the Fourth Amendment to
Lease), a letter agreement dated July 31, 1998 (the Fifth Amendment to Lease),
the Sixth Amendment to Lease, dated December 31, 1999, and the Seventh Amendment
to Lease, dated June 1, 2001, as amended by Letter dated October 2, 2001, as the
same may from time to time be further amended and supplemented, are hereinafter
referred to collectively as the "Prime Lease." All of the space in the Building
that is now or hereafter leased by Sublandlord pursuant to the Prime Lease is
hereinafter referred to as the "Prime Lease Premises."

      Pursuant to that certain Sublease dated November 1, 2001 as amended by the
First Amendment to Sublease dated as of February 14, 2003 (together the "Amended
Sublease"), Sublandlord leased to Subtenant a portion of the Prime Lease
Premises which comprises approximately 3,226 rentable square feet of laboratory
space on the fifth floor of the Building and is known as and numbered Suite 580
(the "Sublet Premises"). The expiration date of the Amended Sublease is April
30, 2004 (the "Extended Sublease Expiration Date").

      Sublandlord and Subtenant desire to extend the Extended Sublease
Expiration Date to October 31, 2004.

      Capitalized terms used in this Second Amendment to Sublease and not
otherwise defined in the Amended Sublease shall have the meanings established in
the Prime Lease.

      NOW, THEREFORE, in consideration of the mutual covenants and agreements
set forth below, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto covenant and
agree as follows:
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      1.    AMENDED EXTENDED SUBLEASE EXPIRATION DATE. Sublandlord and Subtenant
hereby extend the Extended Sublease Expiration Date from April 30, 2004 to
October 31, 2004 (the "Amended Extended Sublease Expiration Date"). The period
from May 1, 2004 through and including the Amended Extended Sublease Expiration
Date shall be referred to as the "Amended Extended Sublease Term", which Amended
Extended Sublease Term shall be on all of the same terms and conditions as the
Amended Sublease.

      2.    OPTIONS TO EXTEND. Subtenant shall have the right to further extend
the Amended Extended Sublease Expiration Date for two (2) one-month periods (the
"Option Periods") ending on November 30, 2004 and December 31, 2004,
respectively, by providing notice to the Sublandlord of its exercise of such
rights at least sixty (60) days before the date on which the Amended Sublease
would otherwise expire (October 31, 2004 and November 30, 2004, respectively).
All of the terms and conditions of the Amended Subleases shall apply to such
Option Periods.

      3.    BROKERS. Each of the Sublandlord and the Subtenant warrants and
represents that such party has not dealt with any broker in connection with the
consummation of this Second Amendment, except for Trammell Crow Company; and in
the event any claim is made against either party by any other broker or agent
alleging dealings with the representing party, the party against whom the claim
is made shall defend, save harmless and indemnify the other on account of any
loss, cost, damage and expense (including, without limitation, reasonable
attorneys' fees and disbursement) which may be suffered or incurred by the
indemnified party by reason of such claim.

      4.    EFFECT OF AMENDMENT. Except as set forth herein, the Amended
Sublease shall remain unchanged and in full force and effect. All references to
the "Sublease" or the "Amended Sublease" shall be deemed to be references to the
Amended Sublease as amended by this Second Amendment.

      5.    CONSENT OF PRIME LANDLORD. This Second Amendment to Sublease is
expressly conditioned upon Sublandlord and Subtenant first obtaining the prior
written consent of Prime Landlord pursuant to the terms of the Prime Lease.

                            Signatures on next page.

                                      -2-
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      EXECUTED in one or more counterparts by persons or officers hereunto duly
authorized as of the date and year first above written.

                                         SUBLANDLORD:
                                         ARIAD Corporation

Attest: /s/ Joseph Bratica               By: /s/ Edmond M. Fitzgerald
        -------------------                  ------------------------
        Name: Joseph Bratica                 Name: Edmond M. Fitzgerald
              --------------                       --------------------
        Title: Controller                    Title: Chief Financial Officer
               ----------                           -----------------------

                                         SUBTENANT:
                                         ViaCell, Inc.

Attest: /s/ Eric Anderson                By: /s/ Marc Beer
        --------------------                 -------------
        Name: Eric Anderson                  Name: Marc Beer
              -------------                        ---------
        Title: Materials Manager             Title:  CEO
               -----------------                    ------

                                      -3-
<PAGE>
                                     CONSENT

      The undersigned, as landlord under a certain lease dated as of January 8,
1992, by and between Forest City Cambridge, Inc. ("Landlord") and Ariad
Corporation, as assigned to Ariad Pharmaceuticals, Inc. ("Tenant"), as amended
by the First and the Second Amendments to Lease, each dated May 12, 1994, the
Third Amendment to Lease, dated June 1, 1994, a letter agreement, dated December
16, 1996, a letter agreement dated July 31, 1998, the Sixth Amendment to Lease,
dated December 31, 1999, the Seventh Amendment to Lease dated June 1, 2001, and
a letter agreement dated October 2, 2001 (collectively, the "Lease"), for
certain premises (the "Premises") as more particularly described in the Lease, a
portion of which Premises (the "Sublet Premises") have been subleased by Tenant
to ViaCell, Inc. a Delaware corporation pursuant to the terms of that certain
Subleased dated as of November 1, 2000, as amended by that certain First
Amendment to Sublease dated as of February 14, 2003 and that certain Second
Amendment to Sublease dated December 18, 2003 (collectively, the "Sublease"),
hereby consents to the Second Amendment to Sublease, a copy of which is attached
hereto as Exhibit "A", provided that:

      1.    A copy of any notice sent pursuant to the Sublease, as amended,
            shall be sent to Landlord in conformance with the requirements of,
            and to the address provided in, the Lease;

      2.    Subtenant shall have no right, without Landlord's prior written
            consent, to further sublet the Sublet Premises or any portion
            thereof nor shall the Subtenant have any right, without Landlord's
            prior written consent, to assign said Sublease; and

      3.    Subtenant shall name Landlord as an additional insured party under
            any liability policy which Subtenant is required to maintain and,
            prior to taking possession of the Sublet Premises, Tenant shall
            deliver to Landlord a certificate of such insurance.

      Nothing herein contained shall:

      1.    Be deemed to diminish or relieve Tenant of its primary
            responsibility as the tenant under the Lease;

      2.    Be deemed in any way to limit, restrict, or diminish Landlord's
            rights under the Lease;

      3.    Extend, or otherwise increase, Landlord's obligations under the
            Lease; or

      4.    Extent the term of the Lease.

      Without limiting the foregoing, in the event that the Lease is terminated
for any reason, Subtenant shall have no further right to occupy the Sublet
Premises. Anything to the contrary to the provisions and conditions of this
Consent which is contained in any instrument of sublease shall be null and void
and of no for the and effect so far as it relates to the rights and obligations

                                      -4-
<PAGE>
of Landlord. Any and all alterations, additions and improvements in or to the
Sublet Premises shall be subject to Landlord's prior consent.

                                    FOREST CITY CAMBRIDGE, INC.,
                                    An Ohio corporation

                                    By:     /s/ Michael Fairey
                                        ---------------------------
                                    Name:    Michael Fairey
                                          -------------------------
                                    Title:
                                          -------------------------

      Dated:  January 30, 2004

                                      -5-<PAGE>
                                                                 Exhibit 10.28.1

                            SECOND AMENDMENT TO LEASE

      This Second Amendment to Lease ("Second Amendment") is made as of April 4,
2002, by and between ARE-One Innovation Drive, LLC, a Delaware limited liability
company ("Landlord"), and ViaCell, Inc., a Delaware corporation ("Tenant").

                                    RECITALS

      1. Landlord is the landlord and Tenant is the tenant under a Lease dated
as of February 24, 2000, between Landlord and Tenant's predecessor by name
change t.Breeders, Inc., as amended by that certain First Amendment To Lease
dated as of May 31, 2001, between Landlord and Tenant (as amended, the "Lease"),
under which Tenant leases approximately 17,201 rentable square feet of space in
the building commonly known as One Innovation Drive, Worcester, Massachusetts.
Capitalized terms used herein without definition shall have the meanings defined
for such terms in the Lease.

      B. Landlord and Tenant desire to amend the Lease to expand the existing
Premises demised under the Lease by adding approximately 1,300 rentable square
feet located on the first floor of the Building, as depicted on Exhibit A
attached hereto and incorporated herein by this reference (the "New Space").

      C. Landlord and Tenant desire to amend the Lease to, among other things,
add the New Space to the Premises demised under the Lease.

                                    AGREEMENT

      1. The Premises. Effective as of May 1, 2002, the Premises demised under
the Lease shall include the New Space (consisting for all purposes of the Lease
of 1,300 rentable square feet). From and after May 1, 2002, the monthly Base
Rent payable under the Lease shall be increased by $2,545.83 per month to
$30,870.01 per month and Tenant's Share of Operating Expenses shall be 16.03%.
Such Base Rent shall thereafter be subject to Adjustment when and as described
in Section 4(b) of the Lease.

      2. Term; Acceptance of Premises. The term of the lease of the New Space
shall commence as described in Section 1 above and shall terminate when the Term
of the Lease terminates. Tenant shall accept the New Space in its condition as
of the date of delivery of such New Space to Tenant, subject to all applicable
Legal Requirements. Upon such delivery, Landlord shall have no obligation for
any defects in the New Space. Tenant's taking possession of the New Space shall
be conclusive evidence that Tenant accepts the New Space and that the New Space
was in good condition at the time possession was taken.

      3. Security Deposit. Upon delivery to Landlord of a copy of this Second
Amendment executed by Tenant, Tenant shall deliver to Landlord cash in the
amount of $7,637.79 as additional security for Tenant's performance under the
Lease.

      4. Alterations. Any alteration of New Space shall be subject to all of the
provisions of Section 12 of the Lease.

<PAGE>

      5. Miscellaneous.

      (a) This Second Amendment is the entire agreement between the parties with
respect to the subject matter hereof and supersedes all prior and
contemporaneous oral and written agreements and discussions with respect to the
matters addressed herein. This Second Amendment may be amended only by an
agreement in writing signed by the parties hereto.

      (b) This Second Amendment is binding upon and shall insure to the benefit
of the parties hereto, their respective agents, employees, representatives,
officers, directors, divisions, subsidiaries, affiliates, assigns, heirs,
successors in interest and shareholders.

      (c) This Second Amendment may be executed in any number of counterparts,
each of which shall be deemed an original, but all of which when taken together
shall constitute one and the same instrument. The signature page of any
counterpart may be detached therefrom without impairing the legal effect of the
signature(s) thereon provided such signature page is attached to any other
counterpart identical thereto except having additional signature pages executed
by other parties to this Second Amendment attached thereto.

      (d) Landlord and Tenant each represent and warrant that it has not dealt
with any broker, agent or other person (collectively "Broker") in connection
with this transaction, and that no Broker brought about this transaction.
Landlord and Tenant each hereby agree to indemnify and hold the other harmless
from and against any claims by any Broker claiming a commission or other form of
compensation by virtue of having dealt with Tenant or Landlord, as applicable,
with regard to this leasing transaction.

      (e) Except as amended and/or modified by this Second Amendment, the Lease
is hereby ratified and confirmed and all other terms of the Lease shall remain
in full force and effect, unaltered and unchanged by this Second Amendment. In
the event of any conflict between the provisions of this Second Amendment and
the provisions of the Lease, the provisions of this Second Amendment, all of the
terms and provisions of the Lease are hereby amended to the extent necessary to
give effect to the purpose and intent of this Second Amendment.

                            (signatures on next page)

                                      -2-
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      IN WITNESS WHEREOF, this Second Amendment to Lease has been duly executed
and delivered by Landlord and Tenant as of the date first above written.

                                      TENANT:

                                      ViaCell, Inc.
                                      a Delaware corporation

                                      By: /s/ Signature on File
                                         ------------------------------------
                                      Its:
                                          -----------------------------------
                                      LANDLORD:

                                      ARE-One Innovation Drive, LLC
                                      a Delaware limited liability company

                                      By: ALEXANDRIA REAL ESTATE EQUITIES, L.P.,
                                          a Delaware limited partnership,
                                          managing member

                                          By: ARE-QRS CORP.,
                                              a Maryland corporation,
                                              general partner

                                              By: /s/ Signature on File
                                                 -------------------------
                                              Its:
                                                  ------------------------

                                      -3-

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