trials beyond those that we anticipate will be required for the completion of clinical development of a product candidate, or if we experience significant delays in our clinical trials due to patient enrollment or other reasons, we might be required to expend significant additional financial resources and time on the completion of clinical development. In some circumstances, such as the emergence of a significantly more effective therapy from a competitor, it may be appropriate to discontinue a product candidate program. We expect that our cash balance as of March 31, 2022 will enable us to fund our operating expenses and capital requirements into the fourth quarter of 2024.
Recent Developments
On April 6, 2022, we announced that we were notified of the commencement of royalty payments relating to commercial sales of Vaxzevria. Our share of the milestone and royalty payments received by OUI from AstraZeneca in the first quarter of 2022 amounted to approximately $15.0 million.
In April 2022, we launched a program in HPV-associated cancer utilizing the SNAPvax platform, for which we expect to file an Investigational New Drug, or IND, application in the first quarter of 2023. In addition, we are moving forward with an immunotherapeutic designed to induce regulatory T cells. The first indication we will target is celiac disease which should enter the clinic in a similar timeframe.
On April 29, 2022, we received scientific advice from the European Medicines Agency defining a licensure pathway for our candidate MERS vaccine, VTP-500, which allows us to estimate expenses of the development pathway more accurately.
Impact of the COVID-19 Pandemic
The ongoing spread of COVID-19, which we refer to as the COVID-19 pandemic, and the policies and regulations implemented by governments in response to the COVID-19 pandemic have had a significant impact, both directly and indirectly, on the global economy and our business and operations, including continuing disruption to our clinical trial activities. Of note, the initiation of our Phase 1 clinical trial for VTP-500, which was being conducted at the University of Oxford, was paused and discontinued due to COVID-19. In addition, the COVID-19 pandemic has had a negative effect on the operations of our third-party manufacturers and the supply chain for our product candidates and clinical trial materials, due to limitations on travel imposed or recommended by federal, state/provincial, or municipal governments, employers and others.
Our study protocols have been amended so that participants who have previously received Vaxzevria (or any other adenovirus-based vaccine) wait for a minimum of three months between their last adenovirus vaccine and injection with our immunotherapeutic product candidates to prevent prior vector immunity affecting the study.
In the VTP-200 program, the initiation of investigational sites for the Phase 1b/2 clinical trial (HPV001) across all countries has been impacted by COVID-19. The UK is particularly affected as resources to support set up of trials not related to COVID-19 have been low across sites. Other pandemic related issues affecting recruitment include the mass vaccination programs and the adverse publicity early in the second quarter of 2021 around Vaxzevria. Participant recruitment continues to be delayed with last patient first visit anticipated in the second quarter of 2022 and the interim analysis is expected to be available in the fourth quarter of 2022.
For our Phase 1 (HBV001) clinical trial for VTP-300, recruitment of patients with Chronic Hepatitis B (CHB) in the UK has been challenging, due to COVID-19 lockdowns. We completed recruitment for all cohorts in first quarter of 2022. For our Phase 1b/2a (HBV002) clinical trial for VTP-300, CHB patient recruitment continues with delays in Taiwan, South Korea, and the United Kingdom due to the ongoing COVID-19 restrictions in those countries. Patient recruitment has also been delayed in South Korea due to the roll out of Vaxzevria vaccine and vaccine hesitancy. Patient recruitment is estimated to be completed in the second quarter of 2022, with full efficacy data expected in the second half of 2022.
If the disruption due to the COVID-19 pandemic continues, our planned future preclinical and clinical development for our other product candidates could also be delayed due to government orders and site policies as a result of the pandemic. The pandemic and government measures taken in response have also had a significant impact, both direct and indirect, on businesses and commerce, as worker shortages have occurred; supply chains have been disrupted; facilities and production have been suspended; and demand for certain goods and services, such as medical services and supplies, has spiked, while demand for other goods and services, such as travel, has fallen. In response to the spread of COVID-19, in most of 2020 and 2021, we mandated that our non-laboratory based employees, such as clinical, manufacturing, finance, administrative, quality, regulatory and program managers split their time between working from home and the