defined below). The Former Officer is no longer party to the Uncommitted Advance Agreement. Under the Uncommitted Advance Agreement, advances are made by M&F TTP Holdings LLC at its discretion periodically at our Predecessors’ request. There is no minimum or maximum amount for any advance. Advances made under the Uncommitted Advance Agreement bear interest at an annual rate of LIBOR plus 10%. Principal and interest were originally payable on demand, but on May 4, 2015, M&F TTP Holdings LLC agreed to extend the maturity date of the Uncommitted Advance Agreement to January 15, 2016. Prepayments can be made under the Uncommitted Advance Agreement without penalty. As of December 31, 2013, December 31, 2014 and March 31, 2015, $2.0 million, $27.3 million and $36.1 million, respectively, of principal was outstanding under the Uncommitted Advance Agreement. During the year ended December 31, 2014 and the three months ended March 31, 2015, our Predecessors incurred $1.1 million and $0.8 million, respectively, of interest on amounts advanced under the Uncommitted Advance Agreement.
Following completion of this offering, we will not be party to any of the above-described agreements with MacAndrews, and we will not be required to make any payments or perform any other obligations under such agreements. We will also not be able to borrow under the Uncommitted Advance Agreement.
Transactions by Our Predecessors with a Former Officer and Director
On August 9, 2013, in connection with the Rights Offering, our Predecessors issued to Dr. Mjalli (the “Former Officer”), in his capacity as Founding Scientific Investor and Chief Executive Officer of our Predecessors, 218,818,574 shares of Series F Preferred Stock (“Series F Shares”) of TransTech Pharma, Inc., which eventually was converted into vTvx Holdings I (“Predecessor vTvx Holdings I”), and 108,781,071 Series B redeemable convertible preferred units of vTvx Holdings II (“Series B Units”). In the transaction, 193,582,046 of such Series F Shares and 96,235,257 of such Series B Units vested upon the issuance thereof, such that immediately following the closing of Rights Offering, the Former Officer, together with his related entities, held a 20% fully-diluted ownership interest in each of our Predecessors. The remaining Series F Shares and Series B Units were subject to vesting under certain specified conditions. The Series F Shares became Series F convertible preferred units of vTvx Holdings I when Predecessor vTvx Holdings I became a limited liability company, vTvx Holdings I, on November 14, 2013.
On March 28, 2014, our Predecessors entered into a reaffirmation and pledge agreement (“Pledge Agreement”) with the Former Officer. Pursuant to the Pledge Agreement, the Former Officer granted a security interest to us in 18,730,276 Series F convertible preferred units of vTvx Holdings I and 9,363,128 Series B Units owned by the Former Officer (collectively, the “Pledged Units”) to secure the Former Officer’s obligations to our Predecessors under a promissory note (the “2007 Note”) issued by the Former Officer to our Predecessors. The 2007 Note matures on the earlier of March 30, 2018 or the date on which the Former Officer receives in excess of $10 million in proceeds from the sale of any shares of our Predecessors’ capital stock, PharmaCore, Inc. (“PharmaCore”) or any of our Predecessors’ or Pharmacore’s subsidiaries. Interest accrues on the 2007 Note at a rate per annum equal to the lowest rate necessary to meet the Internal Revenue Code requirements for the applicable federal rate and is payable at maturity of the 2007 Note. As of December 31, 2014, 2013 and 2012, the 2007 Note had an aggregate outstanding principal amount of $4.8 million, $4.8 million and $4.8 million, respectively, and accrued and unpaid interest of $1.8 million, $1.6 million and $1.3 million, respectively.
On December 30, 2014, the boards of directors of our Predecessors authorized a repurchase of units of our Predecessors from the Former Officer and entities related to the Former Officer. The terms of the unit repurchase are stipulated in a Letter Agreement (the “Repurchase Agreement”) with the Former Officer and such entities related to him. The Repurchase Agreement stipulated that our Predecessors would repurchase all of the issued and outstanding units of our Predecessors held by the Former Officer and his related entities, including any warrants and options to purchase common units. These included 9,100,001 common units of vTvx Holdings I, 14,462,213 common units of vTvx Holdings II, 108,781,071 Series B Units, 218,818,574 Series F convertible preferred units of vTvx Holdings I, 2,776,522 warrants for common units of vTvx Holdings I, 750,000 warrants for common units of vTvx Holdings II and 58,750 options for common units of vTvx Holdings II (the “Repurchased Units”). All units repurchased by our Predecessors were legally retired and resumed the status of authorized and unissued common and preferred units.
In exchange for the Repurchased Units, under the Agreement, our Predecessors agreed to make periodic cash payments totaling $7.5 million between December 30, 2014 and September 30, 2017. Payments consist