Product Sales, net
Product sales, net represents the gross sales of DEXYCU and YUTIQ less provisions for product sales allowances and accruals. We commenced U.S. commercial sales of YUTIQ in February 2019 and net sales totaled $543,000 for the quarter ended March 31, 2019. We commenced commercial sales of DEXYCU in March 2019 and net sales totaled $684,000 for the quarter ended March 31, 2019. We had no product revenue during the three months ended March 31, 2018. We expect significant increases in product sales by quarter during the remainder of fiscal 2019.
Collaborative Research and Development
Collaborative research and development revenues decreased by 88%, or $459,000 to $65,000 for the three months ended March 31, 2019 compared to $524,000 for the three months ended March 31, 2018. This decrease was attributable primarily to the absence in the current period of $465,000 in revenues recognized from a feasibility study agreement, partially offset by recognition of the remaining $30,000 of deferred revenue associated with the upfront Ocumension license fee.
Royalty Income
Royalty income increased by $316,000, or 78%, to $720,000 for the three months ended March 31, 2019 compared to $404,000 for the three months ended March 31, 2018. The increase was attributable primarily to a combination of an increase in the net sales-based royalty rate from 2% to 4% and higher ILUVIEN net sales under the Amended Alimera Agreement. We expect Retisert royalty income to decline.
Cost of Sales, Excluding Amortization of Acquired Intangible Assets
Cost of sales, excluding amortization of acquired intangible assets, of approximately $330,000 for the three months ended March 31, 2019 consisted of (i) costs associated with the manufacturing of YUTIQ and DEXYCU, certain period costs and product shipping costs and (ii) accrued royalty expense on DEXYCU net sales payable to the former Icon security holders. We expensed manufacturing costs as research and development expenses in the periods prior to FDA approval of the products. In the fourth quarter of 2018, we began capitalizing inventory costs for YUTIQ and DEXYCU manufactured in preparation for our launch in the United States. We had no cost of sales for the three months ended March 31, 2018.
Research and Development
Research and development expenses increased by $472,000, or 14%, to $3.8 million for the three months ended March 31, 2019 from $3.3 million for the same period in the prior year. This increase was attributable primarily to (i) a $768,000 increase in personnel and related expenses for thebuild-out of our medical affairs group and expansion of regulatory and quality staffing, including $81,000 of stock-based compensation, and (ii) a $263,000 increase for medical affairs program expenses, including advisory board meetings and pharmacovigilance, partially offset by decreases of (i) $494,000 of contract research organization costs for our YUTIQ Phase 3 clinical development program and (ii) $196,000 of consulting fees, attributable primarily to our prior year YUTIQ NDA submission.
Sales and Marketing
With the commercial launch of DEXYCU and YUTIQ, we continued thebuild-out of our commercial infrastructure and marketing activities during the first quarter of fiscal 2019. Sales and marketing expense, which totaled $7.3 million in the three months ended March 31, 2019, consisted primarily of (i) $3.0 million related to our contract sales organization which includes 10 YUTIQ and 34 DEXYCU key account managers, (ii) $2.0 million of marketing program and agency costs, (iii) approximately $1.5 million of personnel and related costs, and (iv) $258,000 of professional services primarily related to development of our distribution channel and market access.
General and Administrative
General and administrative expenses increased by $2.3 million, or 102%, to $4.6 million for the three months ended March 31, 2019 from $2.3 million for the same period in the prior year. This increase was attributable primarily to (i) a $1.3 million increase in personnel and related expenses related senior management additions in finance, legal, human resources, information technology and business development, as well as other new hires, including $570,000 of stock-based compensation, (ii) a $417,000 increase in consulting services, primarily for corporate compliance and business development., and (iii) a $218,000 increase in legal, audit and other professional fees.
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