Hello, welcome to Alligator Bioscience, first quarter 2023 call. My name is Søren Bregenholt. I'm the CEO of Alligator Bioscience, and with me I have our CFO, Marie Svensson. Before we dig into all the new data and the numbers, a disclaimer.
Before our webcast, a quick reminder for our listeners. During today's call, management may make forward-looking statements, which by their nature involve known and unknown risks, uncertainties and other important factors beyond the company's control that could cause the company's actual results, performance or achievements to be materially different from that expected result, performance or achievements expressed or implied by such forward-looking statements. These statements are subject to risks and uncertainties that could cause actual results to differ materially from those contained in the forward-looking statements. Actual results and the timing of certain events may differ materially from the results or timings predicted or implied by such forward-looking statements. Reported results should not be considered as an indication of future performance.
Please note that these forward-looking statements made during this call speak only as of today's date, and the company undertakes no obligation to update them to reflect subsequent events or circumstances other to the extent required by law. This call is being webcast and will also be made available through the company's website. With the formalities out of the way, over to management.
Thank you. Let's go to slide three for an overview over the milestones that we have already achieved this year. The start to 2023 has been very busy here at Alligator Bioscience, and I'm happy to share that we've already made a number of significant milestones this quarter. Let's start with OPTIMIZE-1, our phase II trial, where we are evaluating our lead asset mitazalimab in combination with FOLFIRINOX in first-line metastatic cancer. Pancreatic cancer, that is. In January, we reported outstanding phase II interim efficacy data, demonstrating a 52% objective response rate compared to a objective response rate around 30%-32% for the current standard of care alone. These data does exceed our expectation in this challenging indication, the progress that we are making with OPTIMIZE-1 trial further underlines our belief in mitazalimab's clinical and commercial potential.
We've also been receiving a significant amount of interest, both from the clinical community, but definitely also from the pharma community for mitazalimab. Another important milestone for OPTIMIZE-1 was that we earlier this quarter were able to report the completion of the enrollment of the trial. As you may remember, we have already advanced our own expectations and shortened the recruitment time of the trial by approximately nine months. Having now the trial fully recruited allows us to validate and reconfirm that we are on track to deliver top-line data from the trial now in the beginning of Q1 2024.
Staying on mitazalimab, we have used a lot of the experience that we have learned from OPTIMIZE-1 to de-risk and enhance the draw, the design of OPTIMIZE-2, a second phase II trial with mitazalimab, this time in urothelial carcinoma, the most common type of bladder cancer. We're pleased to have now received IND approval from the FDA. We are moving ahead with the initial parts of the trial preparation, which we expect to begin in the first half of 2024 or potentially earlier subject to operational feasibility. This quarter also saw Alligator expanding our research collaboration and license agreement with Orion Corporation to include the discovery and development of another bispecific antibody.
This agreement not only makes Alligator eligible for development, regulatory and sales milestones and royalties for more than EUR 300 million, but it definitely also highlights the power and the uniqueness of our scientific platforms. One point I would like to make about these early-stage collaborations is that they provide significant optionality to Alligator shareholders at no or very limited cost and strongly validate our scientific approaches. Although these collaborations are progressing in the background, they are progressing at quite a fast pace, with already a number of these being in the clinical development since 2017. Notably, our partner at Teva Pharmaceutical Industries and us and Alligator, we dosed the first patient in our joint phase I clinical trial of the molecule called ALG.APV-527 or just 527 for short.
We're expecting to see the first interim readout from that trial, hopefully already in the second half of this year. Still staying on the news, I'd like to highlight the appointment of Laura von Schantz as our new Chief Technology Officer. Laura has a deep and long-lasting knowledge of Alligator and our technologies, as she's been with us since 2014. Laura is the natural choice to oversee the every technical aspects of our both preclinical and clinical pipeline. A warm welcome to Laura in the executive management of Alligator. Lastly, we have also maintained a strong presence at key scientific conferences this quarter, including presentations at several meetings. Lastly, the American Association for Cancer Research annual meeting, where we displayed the latest data on ATOR-4066, our CD40CA bispecific antibody.
We are pleased to see that we've been receiving significant amount of interest in our R&D technology and pipeline at exactly these meetings. Next slide, please. As you can see here, is an overview of internal programs and our collaborations and licensing agreements. I think this gives a very good sense of the robust immuno-oncology pipeline, which we are building with substantial clinical and commercial potential. Our antibodies address key immune activation pathways and are designed with key features, making them complementary to existing cancer therapies. We believe that this gives our antibodies a unique position as part of tomorrow's combination therapies, helping patients with hard to treat cancers, such as pancreatic cancer.
We also place great importance on the value of our partnerships, which provides Alligator with external validation of our technologies, along with the opportunity to generate income, manage risk, and maximize shareholder value in the mid and long term. I've already mentioned Aptevo and Orion, but I'd also like to draw your attention on our long-standing relationship with MacroGenics, AbClon, and Henlius. Next slide, please. Let's spend some time on the interim efficacy data from OPTIMIZE-1 and look ahead to the more mature efficacy data that we plan to generate in the middle of this year. Looking at the overall objective response rate chart as you see here to your left, you can see in orange the 52% response rate that we achieved with mitazalimab in combination with FOLFIRINOX.
To give that number some context, you'll see that the current standard of care, which is standalone FOLFIRINOX, demonstrate an objective response rate around 32% in a similar patient population. This number has been validated in a number of clinical trial settings over the last five years-10 years. That comparison shows that mitazalimab combined with chemotherapy could offer significant clinical benefit for pancreatic cancer patients over standard of care and it really highlights, I believe, in this CD40 agonist in that it could change the treatment paradigm for these patients. The next milestone of this study is the first interim progression-free survival data that we expect to announce mid this year. Beyond that, we, as I said earlier, will provide top-line data in the beginning of the first quarter, 2024.
Now on the next slide, we recap the milestones of mitazalimab development as we've seen them since the treatment of the first patient in September 2021. As you can see, we have met every milestone timely since that point in time. We are now on, well on the way towards providing top-line data in the early parts of Q1 2024, which is then nine months earlier than planned due to the faster than expected patient recruitment that we discussed at a previous point. We see this as a creation of significant value to our pancreatic cancer program, and this indication represents a very large potential market. We have initiated investments to continue our continued our investment in phase III on commercial manufacturing processes as well as other phase III enabling activities with mitazalimab.
We continue to anticipate discussions with the regulators on mitazalimab's development and the route to market, both in the U.S. and in Europe in the second part of this year. The upcoming interim progression-free survival data will be used as a key component of these discussions, and we look very much forward to report the outcome to you in the second half of this year. Slide seven, please. Before I hand over to Marie, I would like to touch up on our financing plans to ensure mitazalimab's development for the mid and the long-term value generation. As you probably know, the financial markets remain extremely challenging for biotech companies like Alligator, even with limited recognition of quality data. Nevertheless, we need to secure the delivery of OPTIMIZE-1 top-line data as we just discussed, with minimal dilution to our current shareholders.
Therefore, we have considered various financing options to serve the best interest of our shareholders. For that reason, we have decided not to enter into, or take on any debt or convertible debt that pushes away equity investors and not to go for multiple small equity raises along the way, which will lead to constant and continuous pressure on the share price. Instead of rather ensure an equity financing to ensure that we have sufficient financial resources to deliver our next catalyst and to allow all Alligator shareholders to continue to support our mission. Thank you to the support of our shareholders. Our preferential rights issue was approved by the shareholders during yesterday's extraordinary general meeting, and I would like to walk you through the main details of it. Next slide, please.
Alligator is in the envious position to have a robust shareholder base who deeply believe in what we are trying to do, are trying to achieve, and who believe in the tremendous potential of mitazalimab in pancreatic cancer and beyond, as well as our overall technology platform and pipeline. Thanks to this support, we've been able to secure over 91% of the SEK 199 million raise that we are kicking off. As mentioned earlier, we want to give existing shareholders the opportunity to contribute and to continue to build on our mission. For that reason, any existing shareholder will be able to acquire two subscription rights for each share they own as of April 26th. Each of these subscription right provides one newly issued common share and also one warrant.
Each collection of eight warrants will allow the shareholders to convert these warrants into one additional new share at a value of 70% of the 10 days weighted average price before August 15, this year, and no less than SEK 4 öre, whatever is the lowest. The subscription period starts on Friday, April 28 and last until May 12 at midnight CET, and we look forward to announce the completion of this financing on May 17 also this year. Now let's turn to Marie to receive and review our financial results for the quarter. Marie.
Thank you. I think we need to go to next slide. Net sales for the first quarter 2023 amounted to SEK 9.6 million , up from SEK 5.4 million in the prior year period. This is a result of the research and license agreement with Orion where we're now running two programs. Operating expense for the quarter resulted in - SEK 62.2 million , from - SEK 43 million in prior year period, mainly due to the cost for the ongoing clinical trials for mitazalimab, ALG.APV-527, and as phase III enabling activities for mitazalimab, as Søren mentioned before. Personnel costs for the period amounted to SEK 18.3 million . An important point I would like to bring to your attention is the focus of financial resources behind our R&D efforts.
While Alligator dedicated around 70% of its operational expense to R&D in 2020 and 2021, the level was significantly increased in 2022, reaching 81.3%. Our efforts have continued, leading us to dedicate 83% in Q1. Cash flow for the quarter amounted to negative SEK 52.2 million compared to SEK 43.8 million in the prior year period. Next slide, please. If we look at Alligator's operating cost on a rolling 12-month basis, we note an increase due to the expansion of our clinical trial activities and the increasing number of patients being enrolled in the trials. At the end of March 2023, Alligator's cash at hand amounted to SEK 44.8 million. In order to support the continued development of our key assets, the company is continuously working on opportunities for partnership, out licensing deals and equity financing.
In March, the company announced that, as Søren mentioned before, that they intend to carry out a 91% guaranteed rights issue that the shareholder meeting approved of yesterday, and that will bring in SEK 199 million before transactions cost. With this rights issue, the company's financial resources are sufficient for the upcoming 12 months. With that, I will turn back to you, Søren.
Thank you, Marie. If I could have the next and final slide. Looking ahead to those next 12 months, we are expecting a very rich news flow with a number of clinical and operational updates on the cards that we expect will continue to validate our technologies and deliver value to our shareholders. I already mentioned the OPTIMIZE 1 milestones, OPTIMIZE 2, and also five-two-seven milestones, we are also now beginning to make arrangement to prepare mitazalimab for its phase III clinical development in pancreatic cancer, which is an exciting next step for Alligator. The upcoming interim progression-free survival data in first-line pancreatic cancer that we expect to report mid-year will be extremely useful combined with the objective response rate of 52% that we've already announced to drive discussions with the regulators on the path forward.
We remain deeply committed to deliver on our ambition to develop meaningful therapies for patients with hard to treat cancers through a continued focus on our key clinical program. On behalf of myself, the board of directors, Alligator's management, and our employees, I would like to take this opportunity to extend our sincere thanks to you as shareholders and also to my team, the Alligator staff, for their very strong achievement and very strong effort during Q1 of 2023. I also want to thank you directly, valued shareholders, for your ongoing confidence in our company. I look forward to keeping you updated on our development on this exciting journey. With that, we will open the call for any questions. Okay. It doesn't seem that there are any questions as we are in a silent period. With that, thank you, Marie.
Thank you.
Thank you out there.