So to the numbers, in the second quarter for 2012, we continue to make good progress in our clinical development efforts, while keeping tight control of our expenses and cash burn rate. Importantly, we have strengthened our balance sheet giving us additional capital resources to pursue our clinical development program. The highlights for the quarter include our operating expenses were down 24% year-over-year. Our revenue from our SC product, SC Proven line of business was up 14% year-over-year. Cash used in operations or our cash burn rate was $5.1 million in Q2 and $10.7 million for the first six months of the year.
We continue to anticipate our 2012 cash burn rate will be in the range of $18 million to $20 million, so we remain on track for that. Our pro forma cash balance was $18.2 million and that includes $9.2 million from the exercise of warrants and the sale of shares subsequent to the end of the quarter.
And lastly, last week, the California Institute for Regenerative Medicine approved a $20 million award to the company and our collaborators. So a little bit more detail on our financials starting with the top line, revenue from product sales increased 14% to $211,000 in the quarter compared to the quarter, second quarter of 2011.
For the six months period of 2012 product revenues are up 44% compared to the same period last year. This solid growth in our SC Proven business is primarily driven by higher unit volumes and only modestly by price increases. We expect continued growth in the SC Proven business via the combination of increased unit sales of existing products and the launch of a number of new products, which is planned for the second half of this year.Our operating expenses declined 24% to $5.5 million in the second quarter of 2012 compared to $7.3 million in second quarter of 2011.