<PAGE>

                                                                 EXHIBIT 10.112
                                                                 --------------

                              CONSENT TO SUBLEASE

     THIS CONSENT TO SUBLEASE (this "Consent") is dated as of July 9, 1999, is
made with reference to that certain sublease dated April 28, 1997 (the "Original
Sublease"), as amended on May __, 1999 (the "Amendment"), by and between
Interneuron Pharmaceuticals, Inc., with an address at 99 Hayden Avenue,
Lexington, Massachusetts Lexington, Massachusetts 02421("Tenant") and J. Howard
& Associates, Inc., with an address at 99 Hayden Avenue, Lexington,
Massachusetts 02421 ("Sublessee"), and is entered into by and among Ledgemont
Realty Trust, with an address at 177 Milk Street, Boston, Massachusetts 02109
("Landlord"), Tenant and Sublessee, with reference to the following facts:

     (A) Landlord and Tenant are the parties to that certain lease dated as of
         February 5, 1997, as amended ("Master Lease");

     (B) Tenant and Sublessee previously entered into the Original Sublease;

     (C) The Master Lease provides, inter alia, that Tenant may enter into the
         Original Sublease, but may not enter into any other sublease without
         Landlord's prior written approval.

     (D) Tenant and Sublessee have herewith presented the fully-executed
         Amendment (a true copy of which is attached hereto) to Landlord for
         Landlord's approval, upon all of the terms and conditions hereinafter
         appearing.

     (E) The Original Sublease as amended by the Amendment is referred to herein
         as the Sublease.

     NOW, THEREFORE, for good and valuable consideration, the parties agree as
follows:

     Landlord hereby consents to the Sublease upon the terms and conditions set
forth in the General Conditions of Consent to Sublease attached hereto and made
an integral part hereof.

     EXECUTED under seal as of the date first written above.

LANDLORD:                              TENANT:

LEDGEMONT REALTY TRUST                 INTERNEURON PHARMACEUTICALS, INC.


By: /s/ Robert L. Beal                 By: /s/ Glenn L. Cooper, M.D.
    -------------------------------        -------------------------------------
    Trustee                                Duly Authorized


                                       SUBLESSEE:

                                       J. HOWARD & ASSOCIATES, INC.


                                       By: /s/ Verna Ford
                                           -------------------------------------
                                           Duly Authorized
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                   GENERAL CONDITIONS OF CONSENT TO SUBLEASE


     The following terms and conditions are an integral part of the foregoing
Consent to Sublease.

     1.  Neither the Master Lease, the Sublease nor this Consent shall be
         deemed, nor are they intended, to grant to Sublessee any rights
         whatsoever against Landlord. Sublessee hereby acknowledges and agrees
         that its sole remedy for any alleged or actual breach of its rights in
         connection with the Sublease shall be solely against Tenant. Sublessee
         acknowledges and agrees that it is not a third party beneficiary under
         the Master Lease, and is not entitled to assert any of Tenant's rights
         thereunder against Landlord, whether in its own right or on behalf of
         Tenant.

     2.  This Consent shall not release Tenant from any existing or future duty,
         obligation or liability to Landlord pursuant to the Master Lease, nor
         shall this Consent change, modify or amend the Master Lease in any
         manner, except insofar as it consititutes Landlord's consent to the
         Sublease. Notwithstanding the generality of the foregoing, (i) this
         Consent expressly shall not absolve Tenant from the requirement set
         forth in the Master Lease that Tenant obtain Landlord's prior written
         approval of any additional subleases, assignments or other dispositions
         of its interest in the Master Lease or the Premises (as defined in the
         Master Lease) an d(ii) this Consent shall not constitute Landlord's
         consent to any alteration of the premises leased under the Master
         Lease.

     3.  In the event Tenant is in default under any of the terms and provisions
         of the Master Lease, Landlord may elect to receive directly from
         Sublessee all sums due or payable to Tenant by Sublessee pursuant to
         the Sublease, and upon receipt of Landlord's notice, Sublessee shall
         thereafter pay to Landlord any and all payments then owing from Tenant.
         Neither the service of such written notice nor the receipt of such
         direct payments shall cause Landlord to assume any of Tenant's duties,
         obligations and/or liabilities under the Sublease, nor shall such event
         impose upon Landlord the duty or obligation to honor the Sublease, nor
         subsequently to accept any purported attornment by Sublessee.

     4.  Sublessee hereby acknowledges that it has read and has knowledge of all
         of the terms, provisions, rules and regulations of the Master Lease and
         agrees not to do or omit to do anything which would cause Tenant to be
         in breach of the Master Lease. Any such act or omission shall also
         constitute a breach of the Master Lease and this Consent and shall
         entitle Landlord to recover any damage, loss, cost, or expense which it
         thereby suffers, from Tenant and/or Sublessee.

     5.  In the event of any litigation between the parties hereto with respect
         to the subject matter hereof the unsuccessful party agrees to pay to
         the successful party all reasonable costs, expenses and attorneys' fees
         incurred therein by the successful party, which may be included as part
         of a judgment rendered therein.

     6.  The parties acknowledge that the Sublease constitutes the entire
         agreement between Tenant and Sublessee with respect to the subject
         matter thereof insofar as Landlord may be concerned, and that no
         amendment, termination, modification or change therein will be binding
         upon Landlord unless Landlord shall have given its prior written
         consent thereto.
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     7.  This Consent shall be binding upon and shall inure to the benefit of
         the parties' respective successors in interest and assigns, subject at
         all times, nevertheless, to all agreements and restrictions contained
         in the Master Lease, the Sublease, and herein, with respect to
         subleasing, assignment, or other transfer. The agreements contained
         herein constitute the entire understanding between the parties with
         respect to the subject matter hereof, and supersede all prior
         agreements, written or oral, inconsistent herewith. Tenant and
         Sublessee warrant and agree that neither Landlord nor any of its agents
         or other representatives have made any representations concerning the
         Premises, their condition, the Sublease or the Master Lease.

     8.  Notice required or desired to be given hereunder shall be effective
         either upon personal delivery or three (3) days after deposit in the
         United States mail, by registered or certified mail, return receipt
         requested, addressed to the Landlord at the address set forth in the
         Master Lease for the payment of rent, or to Tenant or Sublessee at the
         address of the Premises or of the subleased Premises, respectively. Any
         party may change its address for notice by giving notice in the manner
         hereinabove provided.

     9.  Notwithstanding anything to the contrary set forth herein or elsewhere,
         if the Master Lease was guaranteed at the time of execution or at any
         time prior hereto by any guarantor, then Tenant shall deliver to
         Landlord with this Consent a counterpart of this Consent indicating the
         approval thereof by any and all such guarantor(s).

     10. Tenant and Sublessee agree to indemnify and hold Landlord harmless from
         and against any loss, cost, expense, damage or liability, including
         reasonable attorney's fees, incurred as a result of a claim by any
         person or entity (i) that it is entitled to a commission, finder's fee
         or like payment in connection with the Sublease or (ii) relating to or
         arising out of the Sublease or any related agreements or dealings.