Merck KGaA and Intrexon Corp. have altered a 2015 license agreement for the joint development of chimeric antigen receptor T-cell, or CAR-T, therapies.

In March 2015, Merck and Intrexon agreed to collaborate to develop and commercialize CAR-T therapies, which take a person's own immune cells and modifies them to fight cancer cells when infused back into the body. The collaboration utilizes Intrexon's proprietary RheoSwitch Therapeutic System and the Sleeping Beauty non-viral gene integration technology.

Under the new agreement, Darmstadt, Germany-based Merck will receive $150 million in Intrexon shares in exchange for exclusive CAR-T development rights. Precigen, a wholly owned subsidiary of Intrexon, will continue developing the CAR-T technology. The agreement is subject to closing conditions.

Additionally, Germantown, Md.-based Intrexon will issue a $25 million note to Merck, which can be converted to shares of either Precigen or Intrexon.