Selling, general and administrative expenses were $11.6 million for the three months ended December 31, 2020, compared to $12.0 million for the same period in 2019. The decrease during the current period was due to reduced personnel costs from headcount reductions and T&E savings from the prior period, partially offset by an increase in 3rd party expenses relating to our commercial activities.
Research and development expenses were $5.3 million for the three months ended December 31, 2020, compared to $8.0 million for the same period in 2019. The decrease was primarily due to reduced support activities and materials for our LOGICS trial, offset by a small increase in costs from our OPTICS trial in 2020.
For the three months ended December 31, 2020, basic net loss attributable to ordinary shareholders on a GAAP basis was ($11.9 million), or ($0.18) per share, compared to a basic net loss attributable to ordinary shareholders of ($9.0 million), or ($0.17) per share, for the same period in 2019. Net loss for the three months ended December 31, 2020 was higher than the same period in 2019 due to the prior period including income from the termination of a contract offset by an increase in net revenue in the current period. Additionally, there was a $2.3 million change in the revaluation of the fair value of our liability classified warrants recorded in 2020 compared to 2019 due to the increase in our stock price.
For the three months ended December 31, 2020, non-GAAP basic net loss attributable to ordinary shareholders was ($7.6 million), or ($0.11) per share, compared to a non-GAAP basic net loss attributable to ordinary shareholders of ($13.5 million), or ($0.25) per share, for the same period in 2019. The decrease in non-GAAP net loss during the three months ended December 31, 2020 due to the increase in KEVEYIS revenues and overall lower expenses.
Year-to-Date 2020 Financial Results
The Company’s net revenues from sales of KEVEYIS increased $9.0 million, or 41.5%, from $21.7 million for the twelve months ended December 31, 2019 to $30.7 million for the twelve months ended December 31, 2020. The Company recorded cost of sales of $2.2 million for the twelve months ended December 31, 2020, compared to cost of sales of $3.8 million for the same period in 2019. Cost of sales decreased due to changes in the assumptions underlying the allocation between the purchase price of our inventory and our supply agreement. Our gross margins were 93% for twelve months ended December 31, 2020, compared to gross margins of 82% for the same period in 2019.
Selling, general and administrative expenses were $40.9 million for the twelve months ended December 31, 2020, compared to $49.1 million for the same period in 2019. The decrease during the current period was due to reduced personnel costs from headcount reductions, reduced spending due to COVID-19, and lower third-party expenses. Additionally, the prior period had $3.2 million in one-time charges for severance expense.
Research and development expenses were $25.8 million for the twelve months ended December 31, 2020, compared to $30.9 million for the same period in 2019. The spending reduction was primarily due to decreases in product development and supporting activities resulting from the