UNITED
STATES SECURITIES AND EXCHANGE COMMISSION

Washington,
D.C. 20549



FORM
10-K/A

(Amendment
No. 1)



(Mark
One)

☒ ANNUAL
REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.

For
the Fiscal Year Ended December 31, 2017

☐ TRANSITION
REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.

For
the transition period from ____________ to ____________

Commission
File No. 000-16929

SOLIGENIX,
INC.

(Exact
name of registrant as specified in its charter)



|Delaware                                                                               |  | 41-1505029                                                     
|-------------------------------------------------------------------------------------- |  | ---------------------------------------------------------------
|(State
        or other jurisdiction of
        incorporation
        or organization) |  | (I.R.S.
        Employer
        Identification
        Number)



|29
        EMMONS DRIVE, SUITE B-10
        PRINCETON,
        NJ |  | 08540         
|----------------------------------------------------------------- |  | --------------
|(Address
    of principal executive offices)                      |  | (Zip
    Code)



(609)
538-8200

(Registrant’s
telephone number, including area code)

Securities
registered under Section 12 (b) of the Exchange Act:

|Title
    of Each Class                     |  | Name
    of Each Exchange on Which Registered
|------------------------------------------- |  | ---------------------------------------------
|Common
    Stock, par value $.001 per share |  | Nasdaq                                       
|Common
    Stock Purchase Warrants          |  |                                              



Securities
registered under Section 12(g) of the Exchange Act: None

Indicate
by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ Noþ

Indicate
by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ Noþ

Indicate
by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange
Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports),
and (2) has been subject to such filing requirements for the past 90 days. YesþNo ☐

Indicate
by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive
Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the
preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). YesþNo ☐

Indicate
by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not
be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference
in Part III of this 10-K or any amendments to this Form 10-K.þ

Indicate
by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller
reporting company. See the definition of “large accelerated filer”, “accelerated filer” and “smaller
reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

|Large
    accelerated filer | ☐                                               | Accelerated
    filer         | ☐
|--------------------------- | ----------------------------------------------- | ----------------------------- | -
|Non-accelerated
    filer   | ☐ (Do
not check if a smaller reporting company) | Smaller
    reporting company | ☒
|                            | Emerging
    growth company                     | ☐                            



If
an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for
complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Indicate
by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ Noþ

The
aggregate market value of the common stock held by non-affiliates of the registrant was approximately $11,541,350 (assuming, for
this purpose, that executive officers, directors and holders of 10% or more of the common stock are affiliates), based on the
closing price of the registrant’s common stock as reported on The Nasdaq Capital Market on June 30, 2017.

As
of March 9, 2018, 8,740,723 shares of the registrant’s Common Stock, par value $0.001 per share, were outstanding.

DOCUMENTS
INCORPORATED BY REFERENCE: None.














EXPLANATORY
NOTE



This
Amendment No. 1 to Form 10-K (this “Amendment”) amends the Annual Report on Form 10-K for the fiscal year ended
December 31, 2017 originally filed on March 15, 2018 (the “Original Filing”) by Soligenix, Inc., a Delaware corporation
(“Soligenix,” the “Company,” “we,” or “us”). We are filing this Amendment to (a)
adjust the value of common stock option awards and the total compensation for all Named Executive Officers as set forth in the
Summary Compensation Table in Item 11, as the option award values included in the Original Filing overestimate the grant date
fair value of stock options, which resulted in an overestimation of the total compensation paid to the Named Executive Officers,
(b) add a footnote regarding certain stock options held by Christopher J. Schaber, PhD, our President and Chief Executive Officer
that were no longer outstanding, and (c) correct the number of securities underlying unexercised, but exercisable, options held
by, Oreola Donini, our Chief Scientific Officer and Senior Vice President.



Except
as described above, no other changes have been made to the Original Filing. The Original Filing continues to speak as of the date
of the Original Filing, and we have not updated the disclosures contained therein to reflect any events which occurred at a date
subsequent to the filing of the Original Filing.










Table
of Contents



|Item      |  | Description                                    |  | Page
|--------- |  | ---------------------------------------------- |  | ----
|11.       |  | Executive
    Compensation                     |  | 1   
|15.       |  | Exhibits
    and Financial Statement Schedules |  | 4   
|Signature |  | 5                                             



i







Item
11. Executive Compensation



Summary
Compensation



The
following table contains information concerning the compensation paid during each of the two years ended December 31, 2017 to
our Chief Executive Officer and each of the three other most highly compensated executive officers during 2017 (collectively,
the “Named Executive Officers”).



Summary
Compensation



|Name                          |  | Position  |  | Year |  | Salary |         |  | Bonus |   |         | Option
 Awards |  |   | All Other
 Compensation |  |  | Total |       
|----------------------------- |  | --------- |  | ---- |  | ------ | ------- |  | ----- | - | ------- | -------------- |  | - | ----------------------- |  |  | ----- | ------
|Christopher
    J. Schaber(1) |  | CEO &     |  | 2017 |  | $      | 443,668 |  |       | $ | 106,480 |                |  | $ | 78,898                  |  |  | $     | 44,529
|                              |  | President |  | 2016 |  | $      | 434,969 |  |       | $ | 121,792 |                |  |   |                         |  |  | $     | 41,511
|                              |  |           |  |      |  |        |         |  |       |   |         |                |  |   |                         |  |  |       |       
|Oreola
    Donini(2)          |  | CSO &     |  | 2017 |  | $      | 220,000 |  |       | $ | 44,933  |                |  | $ | 80,588                  |  |  | $     | 4,627 
|                              |  | Senior VP |  | 2016 |  | $      | 202,400 |  |       | $ | 35,880  |                |  |   |                         |  |  | $     | 4,657 
|                              |  |           |  |      |  |        |         |  |       |   |         |                |  |   |                         |  |  |       |       
|Karen
    Krumeich (3)        |  | CFO &     |  | 2017 |  | $      | 226,440 |  |       | $ | 44,835  |                |  | $ | 80,588                  |  |  | $     | 15,184
|                              |  | Senior VP |  | 2016 |  | $      | 120,250 |  |       | $ | 23,976  |                |  | $ | 56,269                  |  |  | $     | 7,849 
|                              |  |           |  |      |  |        |         |  |       |   |         |                |  |   |                         |  |  |       |       
|Richard
    C. Straube(4)     |  | CMO &     |  | 2017 |  | $      | 323,060 |  |       | $ | 56,213  |                |  | $ | 80,588                  |  |  | $     | 29,560
|                              |  | Senior VP |  | 2016 |  | $      | 316,725 |  |       | $ | 68,413  |                |  |   |                         |  |  | $     | 27,919










|(1) | Dr.
    Schaber deferred the payment of his 2017 bonus of $106,480 until January 15, 2018. Option awards figure includes the value
    of Common Stock option awards at grant date as calculated under FASB ASC 718 and reflects that, as of July 30, 2018, options
    to purchase a total of 70,000 shares of Common Stock at a weighted average exercise of $2.48 per share were no longer outstanding.
    Other compensation represents health insurance costs paid by the Company.
|--- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|(2) | Dr.
    Donini deferred the payment of her 2017 bonus of $44,933 until January 15, 2018. Option awards figure includes the value of
    Common Stock option awards at grant date as calculated under FASB ASC 718. Other compensation represents health insurance
    costs paid by the Company.
|--- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|(3) | Ms.
    Krumeich deferred the payment of her 2017 bonus of $44,835 until January 15, 2018. Option awards figures include the value
    of Common Stock option awards at grant date as calculated under FASB ASC 718. Other compensation represents health insurance
    costs paid by the Company.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|(4) | Dr.
    Straube deferred the payment of his 2017 bonus of $56,213 until January 15, 2018. Option awards figure includes the value
    of Common Stock option awards at grant date as calculated under FASB ASC 718. Other compensation represents health insurance
    costs paid by the Company.
|--- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Employment
and Severance Agreements



In
August 2006, we entered into a three-year employment agreement with Christopher J. Schaber, PhD. Pursuant to this employment agreement
we agreed to pay Dr. Schaber a base salary of $300,000 per year and a minimum annual bonus of $100,000. Dr. Schaber’s employment
agreement automatically renews every three years, unless otherwise terminated, and was automatically renewed in December 2007,
December 2010, December 2013 and December 2016 for an additional term of three years. We agreed to issue him options to purchase
12,500 shares of our common stock, with one third immediately vesting and the remainder vesting over three years. Upon termination
without “Just Cause” as defined by this agreement, we would pay Dr. Schaber nine months of severance, as well as any
accrued bonuses, accrued vacation, and we would provide health insurance and life insurance benefits for Dr. Schaber and his dependents.
No unvested options shall vest beyond the termination date. Dr. Schaber’s monetary compensation (base salary of $300,000
and bonus of $100,000) remained unchanged from 2006 with the 2007 renewal. Upon a change in control of the Company due to merger
or acquisition, all of Dr. Schaber’s options shall become fully vested, and be exercisable for a period of five years after
such change in control (unless they would have expired sooner pursuant to their terms). In the event of his death during the term
of the agreement, all of his unvested options shall immediately vest and remain exercisable for the remainder of their term and
become the property of Dr. Schaber’s immediate family.



1







In
February 2007, our Board of Directors authorized the issuance of 5,000 shares to Dr. Schaber immediately prior to the completion
of a transaction, or series or a combination of related transactions negotiated by our Board of Directors whereby, directly or
indirectly, a majority of our capital stock or a majority of our assets are transferred from the Company and/or our stockholders
to a third party. The amended agreement with Dr. Schaber includes our obligation to issue such shares to him if such event occurs.



On
June 22, 2011, the Compensation Committee eliminated his fixed minimum annual bonus payable and revised it to an annual targeted
bonus of 40% of his annual base salary. On December 10, 2015, the Compensation Committee approved an increase in salary for Dr.
Schaber to $434,969. On December 14, 2016, the Compensation Committee approved an increase in salary for Dr. Schaber to $443,668.
On December 7, 2017, the Compensation Committee approved an increase in salary for Dr. Schaber to $452,541.



In
July 2013, we entered into a one-year employment agreement with Oreola Donini, PhD, our Vice President Preclinical Research &
Development. Pursuant to the agreement, we have agreed to pay Dr. Donini $170,000 (CAD) per year and a targeted annual bonus of
20% of base salary. We also agreed to issue her options to purchase 40,000 shares of our common stock with one-quarter immediately
vesting and the remainder vesting over three years. Dr. Donini’s employment agreement automatically renews each year, unless
otherwise terminated, and has automatically renewed each year since execution. Upon termination without “Just Cause”,
as defined in Dr. Donini’s employment agreement, we would pay Dr. Donini three months of severance, accrued bonuses and
vacation, and health insurance benefits. No unvested options vest beyond the termination date. In December 2014, Dr. Donini was
named Chief Scientific Officer and Senior Vice President. On December 10, 2015, the Compensation Committee approved an increase
in salary for Dr. Donini to $202,400. On December 14, 2016, the Compensation Committee approved an increase in salary for Dr.
Donini to $220,000. On December 7, 2017, the Compensation Committee approved an increase in salary for Dr. Donini to $230,000.



In
December 2014, we entered into a one-year employment agreement with Richard C. Straube, MD, our Chief Medical Officer and Senior
Vice President. Pursuant to the agreement, we have agreed to pay Dr. Straube $300,000 per year and a targeted annual bonus of
30% of base salary. We also agreed to issue him options to purchase 10,000 shares of our common stock with one-third immediately
vesting and the remainder vesting over three years. Dr. Straube’s employment agreement automatically renews each year, unless
otherwise terminated, and has automatically renewed each year since execution. Upon termination without “Just Cause”,
as defined in Dr. Straube’s employment agreement, we would pay Dr. Straube three months of severance, accrued bonuses and
vacation, and health insurance benefits. No unvested options vest beyond the termination date. On December 10, 2015, the Compensation
Committee approved an increase in salary for Dr. Straube to $316,725. On December 14, 2016, the Compensation Committee approved
an increase in salary for Dr. Straube to $323,060. On December 7, 2017, the Compensation Committee approved an increase in salary
for Dr. Straube to $329,521.



On
June 16, 2016, we entered into a one-year employment agreement with Karen Krumeich, our Senior Vice President and Chief Financial
Officer. Pursuant to the agreement, we have agreed to pay Ms. Krumeich $222,000 per year and a targeted annual bonus of 30% of
base salary. We also agreed to issue her options to purchase 10,000 shares of our common stock with one-quarter immediately vesting
and the remainder vesting over three years. Ms. Krumeich’s employment agreement automatically renews each year, unless otherwise
terminated. Upon termination without “Just Cause”, as defined in Ms. Krumeich’s employment agreement, we would
pay Ms. Krumeich three months of severance, accrued bonuses and vacation, and health insurance benefits. No unvested options vest
beyond the termination date. On December 14, 2016, the Compensation Committee approved an increase in salary for Ms. Krumeich
to $226,440. On December 7, 2017, the Compensation Committee approved an increase in salary for Ms. Krumeich to $230,969.



2







Outstanding
Equity Awards at Fiscal Year-End



The
following table contains information concerning unexercised options, stock that has not vested, and equity incentive plan awards
for the Named Executive Officers outstanding at December 31, 2017, as adjusted for the reverse stock split of one-for-ten effective
October 7, 2016. We have never issued Stock Appreciation Rights.



|                       |  | Number
of SecuritiesUnderlying UnexercisedOptions(#) |        |     | Equity
 Incentive
 Plan
 Awards:
 Number of
 Securities
 Underlying
 Unexercised
 Unearned |  |        | Option Exercise Price |  |  | Option
 Expiration
|---------------------- |  | ---------------------------------------------------- | ------ | --- | ------------------------------------------------------------------------------------------ |  | ------ | --------------------- |  |  | ------------------
|Name                   |  | Exercisable                                          |        |     | Unexercisable                                                                              |  |        | Options (#)           |  |  | ($)               
|Christopher J. Schaber |  |                                                      | 2,500  |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 4,500  |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 14,000 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 11,000 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 11,219 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 13,000 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 10,000 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 10,000 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 10,500 |     |                                                                                            |  | 3,500  |                       |  |  | 3,500             
|                       |  |                                                      | 21,875 | (1) |                                                                                            |  | 28,125 | (1)                   |  |  | 28,125            
|                       |  |                                                      | 20,000 | (2) |                                                                                            |  | 60,000 | (2)                   |  |  | 60,000            
|                       |  |                                                      |        |     |                                                                                            |  |        |                       |  |  |                   
|Oreola Donini          |  |                                                      | 4,000  |     |                                                                                            |  | -      |                       |  |  |                   
|                       |  |                                                      | 2,000  |     |                                                                                            |  | -      |                       |  |  |                   
|                       |  |                                                      | 3,000  |     |                                                                                            |  | -      |                       |  |  |                   
|                       |  |                                                      | 7,000  |     |                                                                                            |  | 1,746  |                       |  |  | 1,746             
|                       |  |                                                      | 8,750  |     |                                                                                            |  | 11,250 |                       |  |  | 11,250            
|                       |  |                                                      | 8,750  |     |                                                                                            |  | 26,250 |                       |  |  | 26,250            
|                       |  |                                                      |        |     |                                                                                            |  |        |                       |  |  |                   
|Richard C. Straube     |  |                                                      | 10,000 |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 5,000  |     |                                                                                            |  | -      |                       |  |  | -                 
|                       |  |                                                      | 5,254  |     |                                                                                            |  | 1,746  |                       |  |  | 1,746             
|                       |  |                                                      | 8,750  |     |                                                                                            |  | 11,250 |                       |  |  | 11,250            
|                       |  |                                                      | 8,750  |     |                                                                                            |  | 26,250 |                       |  |  | 26,250            
|                       |  |                                                      |        |     |                                                                                            |  |        |                       |  |  |                   
|Karen Krumeich         |  |                                                      | 6,250  |     |                                                                                            |  | 3,750  |                       |  |  | 3,750             
|                       |  |                                                      | 8,750  |     |                                                                                            |  | 11,250 |                       |  |  | 11,250            
|                       |  |                                                      | 8,750  |     |                                                                                            |  | 26,250 |                       |  |  | 26,250            








(1)
This option was no longer outstanding as of July 30, 2018.

(2)
This option was no longer outstanding as to 20,000 shares as of July 30, 2018.



3







Compensation
of Directors



The
following table contains information concerning the compensation of the non-employee directors during the fiscal year ended December
31, 2017.



|Name              |  | Fees
 Earned
 Paid in
 Cash (1) |        |  | Option
 Awards (2) |   |        | Total | 
|----------------- |  | ------------------------------- | ------ |  | ------------------ | - | ------ | ----- | 
|Keith L .Brownlie |  | $                               | 55,000 |  |                    | $ | 30,000 |       | 
|Marco M. Brughera |  | $                               | 40,000 |  |                    | $ | 30,000 |       | 
|Gregg A. Lapointe |  | $                               | 47,500 |  |                    | $ | 30,000 |       | 
|Robert J. Rubin   |  | $                               | 52,500 |  |                    | $ | 30,000 |       | 
|Jerome B. Zeldis  |  | $                               | 50,000 |  |                    | $ | 30,000 |       | 










|(1) | Directors
    who are compensated as full-time employees receive no additional compensation for service on our Board of Directors. Each
    independent director who is not a full-time employee is paid $35,000 annually, on a prorated basis, for their service on our
    Board of Directors, the chairman of our Audit Committee is paid $15,000 annually, on a prorated basis, and the chairmen
    of our Compensation and Nominating Committees will be paid $10,000 annually, on a prorated basis. Additionally, Audit
    Committee members are paid $7,500 annually and Compensation and Nominating Committee members are paid $5,000 annually. This
    compensation is paid quarterly.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|(2) | We
    maintain a stock option grant program pursuant to the nonqualified stock option plan, whereby members of our Board of Directors
    or its committees who are not full-time employees receive an initial grant of fully vested options to purchase 1,500 shares
    of common stock. Upon re-election to the Board, each Board member will receive stock options with a value of $30,000, calculated
    using the closing price of the common stock on the trading day prior to the date of the annual meeting of the Company’s
    stockholders, which vest at the rate of 25% per quarter, commencing with the first quarter after each annual meeting of stockholders.
|--- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



Stock
Ownership Policy



In
April 2012, our Board of Directors adopted a stock ownership policy applicable to our non-employee directors to strengthen the
link between director and stockholder interests. Pursuant to the stock ownership policy, each non-employee director is required
to hold a minimum ownership position in the common stock equal to the annual cash compensation paid for service on the Board of
Directors, exclusive of cash compensation paid for service as a chair or member of any committees of the Board of Directors.



Stock
counted toward the ownership requirement includes common stock held by the director, unvested and vested restricted stock, and
all shares of common stock beneficially owned by the director held in a trust and by a spouse and/or minor children of the director.
The policy provides that the ownership requirement must be attained within three years after the later of June 21, 2012 and the
date a director is first elected or appointed to the Board of Directors. To monitor progress toward meeting the requirement, the
Nominating Committee will review director ownership levels at the end of March of each year. Non-employee directors are prohibited
from selling any shares of common stock unless such director is in compliance with the stock ownership policy. A copy of our director
compensation and stock ownership policy is publicly available on our website at www.soligenix.com under the “Investors”
section.



Item
15. Exhibits and Financial Statements Schedules



| | (3) | Exhibits:
| | --- | ---------



The
exhibits listed in the exhibit index of the Original Filing and the exhibits listed in the exhibit index of this Amendment are
filed with, or incorporated by reference in, this report.



4







SIGNATURES



Pursuant
to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this Amendment
to be signed on its behalf by the undersigned, thereunto duly authorized, on the 17th day of August, 2018.



| | SOLIGENIX,
    INC.
| | -------------------
| |                    
| | By:                
| |                    
| |                    



5







EXHIBIT
INDEX



The
following exhibits are included in this Amendment (and are numbered in accordance with Item 601 of Regulations S-K). Pursuant
to Item 601(a)(2) of Regulation S-K, this exhibit index immediately precedes the exhibits.



|Exhibit
                                                                                                                            Number |  | Description                                                                                                                                                                                          
|------------------------------------------------------------------------------------------------------------------------------------------ |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                                                                                                                                           | 
|31.3*                                                                                                                                      |  | Certificate of Chief Executive Officer Pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, dated August 17, 2018.
|                                                                                                                                           | 
|31.4*                                                                                                                                      |  | Certificate of Chief Financial Officer Pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a) as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, dated August 17, 2018.










|* | Filed
    herewith.
|- | -------------------



6