Exhibit 10.5(a)

FIRST AMENDMENT TO EMPLOYMENT LETTER AGREEMENT

This FIRST AMENDMENT TO EMPLOYMENT LETTER AGREEMENT (this “Amendment”) is made
and entered into effective as of November 15, 2007 by and between HELIX
BIOMEDIX, INC., a Delaware corporation (“Helix”), and ROBIN L. CARMICHAEL
(“Employee”).

RECITALS

WHEREAS, Helix and Employee entered into a letter agreement dated October 8,
2007 (the “Agreement”); and

WHEREAS, Helix and Employee wish to amend the Agreement as provided herein.

AGREEMENT

NOW, THEREFORE, in consideration of the premises, the mutual covenants of the
parties hereinafter set forth and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties hereto
agree as follows:

1. The second paragraph of Section 5 of the Agreement is hereby amended and
restated in its entirety as follows:

“In addition, subject to approval by the Board of Directors, you shall be
eligible to receive an option to purchase an additional 100,000 shares of the
Company’s common stock with an exercise price equal to the fair market value on
the date of grant, which option shall vest as follows: (i) if the Company
recognizes Net Revenue (as defined below) of at least $1.5 million but less than
$2.0 million in 2008, an aggregate of 25,000 shares shall vest and become
exercisable; (ii) if the Company recognizes Net Revenue of at least $2.0 million
but less than $2.25 million in 2008, an aggregate of 75,000 shares shall vest
and become exercisable; and (iii) if the Company recognizes Net Revenue of at
least $2.25 million in 2008, an aggregate of 100,000 shares shall vest and
become exercisable. This option will be subject to the terms of the Company’s
2000 Stock Option Plan and the applicable stock option agreement between you and
the Company and is intended to be an incentive stock option to the extent
allowed under applicable law. For purposes of this Section 5, “Net Revenue”
shall mean revenue derived by the Company from the sale or license of
non-pharmaceutical products in connection with licensing or joint development
transactions as determined in good faith by the Board of Directors based on the
Company’s audited 2008 financial statements; provided, however, that Net Revenue
shall not include revenue derived from the sale of peptides at cost or from cost
reimbursements from DermaVentures LLC.”

2. The parties hereto hereby acknowledge the continuing effect of the Agreement
except as specifically modified by this Amendment.

IN WITNESS WHEREOF, the parties hereto have executed this Amendment as of the
day and year first above written.

 

HELIX BIOMEDIX, INC.     EMPLOYEE: /s/ R. Stephen Beatty     /s/ Robin L.
Carmichael By:  

R. Stephen Beatty      

President and CEO      

   

Robin L. Carmichael