Thanks, Ronnie. Our full results on Form 10-K will be filed with the SEC on or before July 29. Overall, we had another year of significant financial milestones for Champions Oncology. Our annual revenue for 2022 was a record $49.1 million compared to $41 million for 2021, representing year-over-year growth of 20% and coming in at the high end of our guidance of 15% to 20%.
Excluding stock comp and depreciation, our adjusted EBITDA, which excludes stock-based compensation, depreciation and amortization was $3.1 million for 2022 compared to $2.1 million a year ago. On a GAAP basis, income from operations for fiscal 2022 was $605,000 compared to income from operations of $337,000 in the year ago period.
Turning the focus to the fourth quarter. Revenue increased to $12.9 million compared to $10.6 million in the year ago period, an increase of $2.3 million or 22%. Adjusted EBITDA was $445,000 compared to breakeven results in the year ago period. Focusing as we do on adjusted EBITDA, total cost of sales was $6 million compared to $5.6 million in our fourth quarter last year, a modest 8% increase on revenue growth of 22%. The increase compared to the prior year was primarily related to SaaS expenses, which are no longer capitalized.
Our total gross margin for the fourth quarter was 53% compared to 47% for the period ended April 30, 2021. Our gross margin for the full fiscal year was 53% compared to 48% for fiscal 2021. As discussed throughout the year, our reduction in outsourcing Ex Vivo work coupled with the leverage in our operating model has led to the gross margin improvement.
Additionally, the gross margin continues to be driven primarily from our legacy services with room for additional expansion as higher-margin products such as Ex Vivo will actually contribute more meaningfully to revenue in the future. For the fourth quarter, R&D expense was approximately $2.6 million compared to $2.1 million in the year ago period.
For the year, R&D expense was $9.4 million compared to $7.2 million for fiscal 2021. The $500,000 quarterly increase and the year-over-year $2.2 million increase are attributed to our stated strategy to ramp up our R&D spend, specifically investing in our discovery platform. We anticipate the trend to continue in fiscal year 2023 with increases in R&D spend focused on target discovery initiatives.
For the fourth quarter, sales and marketing expense was $1.6 million, an increase of $150,000 compared to the fourth quarter last year. For the year, sales and marketing expense was $6.2 million compared to $5.3 million in the year ago period. The increases are primarily attributed to the expansion of our business development team.
Our G&A expense was $2.6 million for the quarter compared to $1.5 million in the year ago period, an increase of $750,000. The increase in the fourth quarter expense was primarily due to a bad debt write-off of $200,000, IT computing costs to support the growth of the business of $250,000 in compensation expense.
For the year, G&A expense was $7.2 million compared to $5.2 million in the year ago period. This was primarily due to an increase in compensation and IT expenses as we invest in upgrading our IT infrastructure to support company growth. Looking ahead to fiscal year 2023, we anticipate a lower level of G&A increases, and G&A as a percentage of revenue is expected to decline.
Now turning to cash. We ended the year in a strong cash position with $9 million of cash on the balance sheet. For the quarter, cash generated from operating activities was $700,000, and cash used for investment in lab equipment was $400,000. For the year, cash generated by operating activities was a robust $6.5 million, and cash used for CapEx investment was $2.4 million.
Looking ahead to fiscal year 2023, with continued strength in our bookings and improving cash-based operating results, we anticipate that cash generated from operating activities will grow over the year. Our planned CapEx expense is -- CapEx spend is in the $3 million range. We're targeting CapEx for our Ex Vivo platform as investing in lab automation will increase capacity and productivity, allowing us to increase our revenue and expand our margins.
In all, our cash position is expected to strengthen over the course of fiscal year 2023. Information reflecting on our fiscal year 2022 results reached another annual revenue record as we exceeded $49 million, growing our revenue by 20% and hitting the top range of our revenue guidance.
For the full year, we were profitable on both a GAAP and adjusted EBITDA basis, with adjusted EBITDA of $3.1 million. Our bookings remain strong, and we are positioned to capitalize on the exciting opportunities that lie ahead. We're projecting revenue growth in the 20% range, which will result in another annual revenue record as we hit new quarterly revenue milestones over the course of the fiscal year. We have already almost completed with our first quarter. Accordingly, we look forward to another update in about 6 weeks when we report our first quarter results.
We'll now open the floor for questions.