Preclinical and clinical activities for the mRNA antagonists using LNA technology amounted to $4.7 million in the second quarter compared to $8.0 million in the second quarter of 2009. Second quarter 2010 costs included a $1.0 million milestone payment for the HER3 antagonist. During the second quarter of 2009, the Company purchased raw materials used in the manufacturing process of the LNA compounds and manufacture of additional clinical drug supply for the ongoing Phase I studies for the HIF-1 alpha and survivin antagonists. Enrollment in the Phase I clinical trials for the HIF-1 alpha and survivin antagonists is ongoing and Enzon is continuing preclinical development for the additional six mRNA antagonist-directed oncology targets which are known to play an important role in cancer cell growth. Data from three of our mRNA antagonist programs were presented at the April 2010 American Association for Cancer Research meeting in Washington, DC.
The Company also incurred an expense of $1.0 million during the quarter ended June 30, 2010 related to its efforts to identify additional compounds that may benefit from Enzon's proprietary Customized Linker Technology which is associated with the PEGylation platform. This compares to $0.8 million spent on these efforts in the comparable period of 2009.
As a result of the sale of Enzon's specialty pharmaceutical business in January 2010, the activities related to the specialty pharmaceutical products became the responsibility of the purchaser at the close of the transaction. Enzon continues to assist in the development of the next-generation Adagen and Oncaspar programs through a transition services arrangement. Total expense incurred during the second quarter of 2010 for the next-generation programs and other activities associated with the specialty pharmaceutical products was $1.6 million. The expenses Enzon incurs on these programs are reimbursed with a mark-up and reported as contract research and development revenue which was $2.6 million for the second quarter of 2010. For the quarter ended June 30, 2009, Enzon reported research and development expenses of $9.4 million related to the specialty pharmaceutical products which, at that time, were entirely the responsibility of Enzon.