Ari Bousbib
Chairman and Chief Executive Officer at IQVIA
Thank you very much, Nick, and good morning, everyone. Thank you for joining us today to discuss our first quarter results. This was another quarter where we delivered again on all our financial targets. Our revenue grew 11% organic, excluding the impact of foreign exchange and COVID-related work. The diversification of our short- and long-cycle businesses allowed us to perform well in the quarter despite the broader macroeconomic dynamics. The demand environment for our industry continues to be healthy. Global clinical trial activity remains resilient and the prospects for our commercial business remain favorable. A few encouraging signs I'd like to share with you this morning, the 15 largest pharmaceutical companies together spent a record setting $138 billion on research and development in 2022. According to BioWorld, the Q1 EBP funding was $15.6 billion.
That was up double digit versus prior year and up sequentially versus Q4. March was a particularly strong month for EBP funding despite concerns about the impact from the banking crisis. FDA approvals are off to a strong start in 2023. There were 13 approvals in the first quarter. That's up from an average of nine over the prior five years. And that's a positive indicator for our commercial business. There was a significant M&A activity in Q1, which primarily is large pharma acquiring smaller companies and the industry expects 2023 M&A spend to be one of the largest years in the last decade. This highlights the ongoing demand for molecules by large pharma. Internally, our Q1 demand metrics show continued healthy growth. I'll share a couple with you this morning. Net new bookings were $2.6 billion. That represented a quarterly book-to-bill of 1.28 times. As a result, our backlog reached a new record and grew 10.1% versus prior year on a reported basis and 11.3%, excluding the impact of foreign exchange.
Our RFP flow set a new quarterly record. It was up sequentially 15%, versus Q4 2022. Operationally, attrition levels have continued to decline, and they are now, in fact, back to pre-pandemic levels or slightly below that. Site selection was up double digits year-over-year. This increased productivity helped mitigate the unfavorable impact of the staff's shortages that investigator site that we spoke about in prior calls. R&DS organic revenue growth at constant currency, excluding COVID-related work, was 17% in the quarter. That was well above the upper end of our expectations. Within TAS, we continue to see some client cautiousness related to discretionary spending. TAS growth for the quarter was 6% organic at constant currency, excluding COVID-related work, and that was within our expectations, but towards the lower end. In summary, industry demand remains healthy despite some cautiousness in discretionary spending, mostly in the short-cycle businesses.
The diversification of our businesses allows us to balance the current slower short-cycle growth with the resilience of our long-cycle businesses, demonstrating that IQVIA is a company that can operate effectively under different macro environments. And with that, as context, let me review the first quarter results. Revenue for the first quarter grew 2.4% on a reported basis, 4.7% at constant currency and compared to last year and excluding COVID-related work from both periods, we grew the top line as a company, 11% at constant currency on an organic basis. First quarter adjusted EBITDA increased 4.8%, driven by revenue growth and ongoing cost management discipline. First quarter adjusted diluted EPS of $2.45 declined slightly as expected driven by the onetime step-up in interest rates. Excluding interest expense and the U.K. tax rate headwinds that we discussed in the prior call, our adjusted diluted EPS growth exceeded 9%. I'd like to share a few highlights of business activity in the quarter.
Within TAS, a top 10 pharma awarded IQVIA, our first omnichannel marketing deal in the Asia Pacific region. IQVIA's omnichannel marketing program provides client teams with AI ML powered insights and recommendations to deliver effective personalized digital engagements with HCP. In the quarter, IQVIA won an award for our in-home patient services offering. This biotech client is launching a new MS treatment and selected IQVIA based on our ability to deliver testing and monitoring to the patient's home. These differentiated capabilities ease the burden for patients with limited mobility. Moving to the real-world part of our TAS business. IQVIA was awarded a major post authorization safety study to assess the impact and outcomes of prescribing a certain asthma drug to pregnant women with severe asthma. We won this large contract with a top 10 pharma client due to the breadth of our capabilities, including our relevant experience in the safety trials, our strong data and analytics capabilities and increased delivery efficiency with faster patient enrollment.
Also in the quarter, we were awarded a large global intervention study with a top 10 pharma to identify high-risk cardiovascular patients by measuring the prevalence of high-sensitivity C-reactive protein. This protein is produced by the liver in response to inflammation in the body. Elevated levels of this protein in the blood are associated with an increased risk of cardiovascular disease, including heart attack and stroke. IQVIA was selected based on our ability to connect lab and clinical capabilities with therapeutic and real-world expertise in a cost-efficient manner. This study will have a significant impact on the future management of cardiovascular patients. Moving to R&DS. Continued strong momentum with our $2.6 billion of net new bookings in the quarter, translating into a book-to-bill of 1.28 times in quarter, which brings our LTM book-to-bill to 1.35 times. A few highlights in the quarter.
Oncology continues to be our largest therapeutic area. And in the quarter, a high-profile cutting-edge biotech company entered into a strategic partnership with IQVIA. This is a big deal. In fact, we were already awarded our first trial, which is for a novel bispecific antibody with potential development opportunities across several tumor types. Bispecific antibodies are designed to bind two different target molecules simultaneously. This project will leverage our end-to-end clinical trial solution, including protocol design, specialized medical and regulatory expertise, biomarker development and our integrated clinical operations, analytics and technology. We really are the only company with the ability to bring together these capabilities which, in turn, helped the client optimize trial design and reduce time to market. Importantly, going forward, this partnership creates multiple opportunities within this client's large oncology portfolio.
We continue to have strong success with our clinical FSP trials business with several recent notable wins, including a significant preferred provider award with a major pharma. This was a competitive win against two incumbents and it further diversifies our portfolio of FSP clients and increases our share in that segment. We continue to deploy innovations in our clinical technology suite. Most recently, we introduced a new cloud-based platform within our research site network that will streamline document workflows and allow real-time collaboration among study teams. We already deployed this new technology to approximately 15% of IQVIA network sites across 28 countries, and we expect to deploy it to 40% of our sites in the next 12 months.
The goal of deploying this technology at the site is to increase site productivity, which frees up more time for site support, compliance reviews and continuous monitoring of patient safety and study quality all of which are very important, especially in an environment where we experienced staff shortages at the site. Finally, a couple of nice accolades for our global IQVIA team. First, I am proud to share that our lab business received the prestigious Singaporean President Certificate of commendation, which is awarded to organizations that had a significant impact in the fight against COVID-19. In fact, five of our employees in Singapore received a Public Service Medal Award for their outstanding contributions to manage the impact of the pandemic. This is a nice recognition of the unique role we play in supporting public health. Second, our Scotland-based lab business recently achieved a global green lab certification for its commitment to practicing sustainable science. This certification is recognized by the United Nation's "Race to Zero" global campaign as the international gold standard for lab sustainability best practices towards a zero carbon future.
I will now turn it over to Ron for more details on our financial performance.