Exhibit 10.12d

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THIRD AMENDMENT TO LEASE – EXPANSION

THIS THIRD AMENDMENT is executed at Salt Lake City, Utah between Salt Lake
Research Park Associates, a New Mexico Limited Partnership, by BGK Realty. Inc,
a Delaware Corporation, as General Partner, Landlord, and NPS Pharmaceuticals,
Inc., a Delaware Corporation, Tenant, for the premises located at 420 Chipeta
Way, Suites 140, 200 & 202 Salt Lake Citv, Utah 84108.

Landlord and Tenant being parties to that certain Lease dated June 3, 1994
hereby express their mutual desire and intent to increase the rentable area of
the Leased Premises by 604 square feet (hereafter referred to as “Expansion
Space”) effective March 1, 1997 and amend by this writing those terms, covenants
as hereinafter provided.

> Section 2. Leased Premises and Rentable Area. This Section shall be adjusted
> to provide as follows: That portion of the 1st floor of the building more
> fully shown on the Floor Plan attached hereto as Exhibit “A” – Expansion
> Space. The Rentable Area of the Premises shall hereafter mean: approximately
> 44,791 square feet.
> 
> Section 4. Term. The term for the Expansion Space shall be coterminous with
> the existing Lease.
> 
> Section 5. Rent. This Section shall be adjusted to provide as follows: The
> Rent for the Expansion Space shall be Six Thousand Forty and No/100 Dollars
> ($6,040.00) per annum, payable in monthly installments in the amount of Five
> Hundred Three and 33/100 Dollars ($503.33) in lawful money of the United
> States.
> 
> Section 7. Operating Expenses. Tenant's Proportionate Share shall be adjusted
> to 39.9%.
> 
> Tenant agrees to accept the Expansion Space in its “as is” condition, except
> that Landlord will provide Tenant with an improvement allowance of $3.00 per
> square foot or $1,812.00 for the purpose of making improvements to the
> Expansion Space. All costs in excess of the $3.00 improvement allowance shall
> be the sole responsibility of Tenant.

Except as modified herein, all terms and conditions of the Office Lease shall
remain in full force and effect.

Landlord:
Tenant:
   
Salt Lake Research Park Associates,
a New Mexico Limited Partnership
NPS Pharmaceuticals, Inc., a
Delaware Corporation
   
By: BGK Realty, Inc.
 
Its: General Partner
      By: /s/ Cheryl S. Willoughby By: /s/ Robert K. [Illegible] Title: Senior
Vice President Title: Vice President, Finance Execution Date: March 6, 1997
Execution Date: March 3, 1997

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