Christiana Stamoulis
Executive Vice President & Chief Financial Officer at Incyte
Thank you, Steven, and good morning, everyone.
Our fourth quarter results reflect continued strong revenue growth with total product and royalty revenues of $813 million, representing an increase of 20% over the fourth quarter of 2020 and reflecting growth across products commercialized by Incyte and by our partners. Total product and royalty revenues for the quarter are comprised of net product revenues of $592 million for Jakafi, $51 million for other hematology/oncology products and $5 million for Opzelura, royalties from Novartis of $96 million for Jakavi and $3 million for Tabrecta and royalties from Lilly of $66 million for Olumiant.
This 15% year-over-year growth for Jakafi net product sales reflects higher patient demand across all indications. The doubling of Olumiant royalties is driven primarily by the use of Olumiant for the treatment of COVID-19. As a reminder, for global net sales of Olumiant for the treatment of COVID-19, we are entitled to receive royalty sequel to the base double-digit royalties applicable to all global net product sales, plus an additional 13% royalty. For the full year 2021, total product and royalty revenues were $2.9 billion and a 17% increase over 2020.
Focusing now on Opzelura for the fourth quarter, the launch and volume of prescriptions has been strong. While we are negotiating with PBMs and payers to get Opzelura in formularies and remove the NDC blocks, we have been utilizing patient support programs to cover the full cost of Opzelura so that patients have access to the product. In the fourth quarter, Opzelura gross product sales of $58 million were reduced by 75% related to these patient support programs. In addition, other fees and discounts of 17% contributed to a total gross to net discount of 92% for the quarter. As a result of these reductions, net product sales for the quarter were $5 million.
Moving on to our operating expenses on a GAAP basis. Ongoing R&D expenses of $345 million for the fourth quarter decreased 9% from the prior-year period, primarily due to the ruxolitinib cream API-related costs incurred in the prior year quarter before Opzelura's regulatory approval. Ongoing R&D expense for the full year 2021 of $1.3 billion increased by 6% over 2020, primarily due to the progression of our pipeline. Total R&D expense of $473 million for the quarter and $1.46 billion for the full year 2021 includes upfront consideration of $127 million for our collaborative agreement with Syndax.
SG&A expense for the fourth quarter of $226 million increased 35% from the prior-year period, primarily due to our investments related to the establishment of our new dermatology commercial organization in the US and the related activities to support the launch of Opzelura. For the full year 2021, the 43% growth in SG&A expense was also primarily related to the commercialization of Opzelura.
Our collaboration loss for the quarter was $8 million, representing our 50% share of the US net commercialization loss for Monjuvi. For the full year 2021, the total collaboration loss was $37 million. Finally, we ended the year with $2.3 billion in cash and marketable securities.
Looking at the evolution of our P&L, you can see how over the past three years, the growth in our product and royalty revenues has exceeded the growth in our ongoing R&D and SG&A expenses, leading to increased operating leverage and reflecting our commitment to prudent management of our financial resources. As previously discussed, the uptick in expenses in 2021 reflects the build out of our dermatology franchise and the Opzelura launch.
Moving on to 2022, I will now discuss the components of our guidance on a GAAP basis. For Jakafi, we expect net product revenues to be in the range of $2.3 billion to $2.4 billion, which at midpoint represents an increase of approximately 10% over 2021 driven by continued growth across all indications. We expect our gross to net adjustment for 2022 to be approximately 21%, reflecting expected continued growth in 340B volumes. As a reminder, the gross to net adjustments in the first quarter of the year is always higher relative to the previous quarter and subsequent quarters due to our share of the donut hole for Medicare Part D patients.
For other hematology/oncology products, which includes Pemazyre in the US, EU and Japan and Iclusig and Minjuvi in Europe, we are expecting total net product revenues to be in the range of $210 million to $240 million, which at midpoint represents approximately 23% growth over 2021. Due to the early stage of its launch, we will not be providing guidance on Opzelura, but I will provide some additional color around Opzelura gross to net for 2022 in a moment. As in previous years, we are also not providing guidance for milestones or royalty revenues.
Turning to operating expenses on a GAAP basis, we expect COGS to range from 6% to 7% of product revenues. R&D expense is expected to be in the range of $1.55 billion to $1.59 billion, representing 18% growth at the midpoint versus 2021, excluding the impact of the Syndax upfront consideration in 2021. The growth rate primarily reflects expansion in our dermatology clinical development, as well as investments in our LIMBER GVHD program, tafasitamab and our PD-L1 program.
We expect SG&A expense for the year to be in the range of $950 million to $1 billion, primarily reflecting continued support for the Opzelura launch. Excluding the impact of Opzelura-related cost, we expect SG&A expense to grow at a rate of less than 5%. With respect to our profit share for Monjuvi in the US, in 2022, we expect to be around breakeven.
As I previously mentioned, while we are not providing guidance for Opzelura due to the early stage of the launch, I would like to discuss what you could expect related to our gross to net adjustment in 2022. As we finalize coverage with payers, we expect gross to net for Opzelura to be relatively flat in Q1 compared to Q4 2021, begin to decline in Q2 and normalize at a fully loaded gross to net rate of 40% to 50% between Q3 and Q4, depending on the timing of the removal of NDC blocks by PBMs and the discontinuation of certain patient support programs.
Operator, that concludes our prepared remarks. Please give your instructions and open the call for Q&A.