by occurrence of serious adverse events within first 30 days after administration of Lomecel-B. Secondary and exploratory endpoints include measures of cognitive function, fluid, and radiological biomarkers relevant to inflammation and endothelial and vascular systems. In a previously completed phase 1 study, we demonstrated the preliminary safety of Lomecel-B patients with mild Alzheimer's disease. With the phase 2a trial, we hope to build on those results and further demonstrate the potential of Lomecel-B as a treatment for Alzheimer's disease. Data analysis from this trial is ongoing, we anticipate sharing top line results from CLEAR MIND trial around October 2023. Finally, I'd now like to cover updates on our Aging-Related Frailty program. Aging-Related Frailty is an age-associated decline across multiple physiological system, leading to the inability to cope with stressors.
It is characterized by mobility impairment, weakness, fatigue, weight loss, slowness, and low activity, and puts individual at high risk for poor clinical outcomes, such as infections, falls, fractures, hospitalizations, and even death. At Longeveron, we've been evaluating the effect of Lomecel-B may have on health and function of elderly frail patients, particularly on their physical and immune system function. In early stage exploratory trial, we have been using biomarkers of inflammation and vascular and endothelial function to measure effect. Our clinical development strategy in Aging-Related Frailty is currently focused on Japan, a country with one of the oldest population in the world. As of 2021, Japan's population comprised of 36.4 million individual aged 65 or older, representing 29.1% of the country. The overall prevalence of Aging-Related Frailty amongst the demographic is estimated to be 7.9%.
Last quarter, we announced the dosing of the first patient in our phase 2 clinical trial, evaluating Lomecel-B in patients with Aging-Related Frailty in Japan. The phase 2 trial is a three-arm parallel design, randomized, evenly split, one to one to one of placebo, as well as two different level of Lomecel-B single infusions. Enrollment is continuing, and the trial is expected to enroll 45 patients. The primary endpoint is to evaluate safety, with an overarching goal of providing support for an eventual limited approval under the Japan Act on the Safety of Regenerative Medicine, or ASRM, which recognizes the tremendous potential, therapeutic potential of cell therapy. With that, I'd now like to turn the call over to Lisa Locklear, our CFO, to discuss our financial results for the second quarter of 2023, and the 6-month period ended 30 June 2023. Lisa?
Thanks, Natalia, and good morning, everyone. Like Natalia, I'm excited to be a part of Longeveron and to speak with all of you today. Most of what I'll be covering this morning will be presented in more detail in our condensed financial statements and in our management's discussion and analysis of operations in our quarterly report on Form 10-Q, which will be filed today. Revenues for each of the three months ended June 30, 2023 and 2022, were approximately $0.2 million and $0.5 million, respectively. Grant revenue for the three months ended June 30, 2023 and 2022, was $0 and $0.1 million, respectively.
The decrease of $0.1 million was primarily due to a reduction in grant funds available, due in part to the completion of the grant-funded clinical trials. Clinical trial revenue, which is derived from the Bahamas Registry Trial for the three months ended June thirtieth, 2023 and 2022, was $0.2 million and $0.3 million, respectively. Clinical trial revenue for the three months ended June thirtieth, 2023, was approximately $0.1 million, or 36% lower when compared to the same period in 2022, as a result of a decrease in participant demand. Related cost of revenues was approximately $0.1 million and $0.3 million for the three months ended June thirtieth, 2023 and 2022, respectively.
The decrease of $0.2 million, or 59%, was primarily related to the decrease in revenues earned from the Bahamas Registry Trial. This resulted in a gross profit of approximately $0.1 million and $0.2 million for the three months ended June thirtieth, 2023 and 2022, respectively. General and administrative expenses for the three months ended June thirtieth, 2023, increased to approximately $3.4 million, compared to $2.4 million for the same period in 2022. The increase of approximately $1 million or 3% was primarily related to an increase of $0.7 million in compensation and benefit expenses during the current year period and expenses related to professional fees.
Research and development expenses for the 3 months ended June 30, 2023, increased to approximately $2.3 million, from approximately $1.7 million for the same period in 2022. This increase of $0.6 million and 33% was primarily due to an increase of $0.5 million in research and development expenses that were not reimbursable by grants. Non-operating lawsuit expense for the 3 months ended June 30, 2023, and 2022 was $0 and approximately $1.4 million, respectively. Net loss was approximately $5.6 million for the 3-month period ended June 30, 2023, and 2022.
For the six-month period ended June 30, 2023 and 2022, results were as follows: Revenues for each of the six months ended June 30, 2023 and 2022, were approximately $0.5 million and $0.8 million, respectively. Revenues for this period are approximately $0.3 million, or 41% lower when compared to the same period in 2022. Grant revenue for the six months ended June 30, 2023 and 2022, was less than $0.1 million and $0.2 million, respectively. Grant revenue this period was approximately $0.1 million, or 78% lower when compared to the same period in 2022, primarily due to a reduction in grant funds available, due in part to the completion of the grant-funded clinical trial.
Clinical trial revenue, which is derived from Bahamas Registry Trial for the 6 months ended June 30th, 2023 and 2022, was $0.5 million and $0.6 million, respectively. Clinical trial revenue for this period was approximately $0.1 million, or 30% lower when compared to the same period in 2022. During the 6 months ended June 30th, 2023, clinical trial revenue decreased as a result of a decrease in participant demand. Related cost of revenues was approximately $0.3 million and $0.4 million for the 6 months ended June 30th, 2023 and 2022, respectively. Cost of revenues for this period was $0.1 million or 13% less when compared to the same period in 2022, primarily due to the corresponding decrease in the revenues earned from the Bahamas Registry Trial.
This resulted in a gross profit of approximately $0.2 million and $0.5 million for the six months ended June 30, 2023 and 2022, respectively. General and administrative expenses for the six months ended June 30, 2023, increased to approximately $5.2 million, compared to $4.4 million for the same period in 2022. The increase of approximately $0.8 million or 19%, was primarily related to an increase of $0.8 million in compensation and benefit expenses. Research and development expenses for the six months ended June 30, 2023, increased to approximately $5.1 million from approximately $3.1 million for the same period in 2022.
The increase of $1.9 million, or 61%, was primarily due to an increase of $1.4 million in research and development expenses that were not reimbursable by grants, an increase of $0.3 million in supplies to manufacture Lomecel-B, and an increase in equity-based compensation allocated to research and development expenses of $0.2 million. Non-operating lawsuit expense for the 6 months ended June 30, 2023 and 2022, was 0 and approximately $1.4 million, respectively. Our net loss increased to approximately $10.3 million for the 6 months ended June 30, 2023, from a net loss of $9.1 million for the same period in 2022.
As of June 30, 2023, the company had cash and cash equivalents of $2.7 million, marketable securities of $5.9 million, and working capital of approximately $6.2 million. As of December 31, 2022, cash and cash equivalents were $10.5 million, marketable securities were $9.2 million, and working capital was approximately $15.4 million. Based on the company's current operating plan and financial resources, we believe that our existing cash and short-term investments will be sufficient to cover expenses and capital requirements into the first quarter of 2024.
Before turning over to Wa'el, I want to remind everyone that on June 27, 2023, the company filed a registration statement with the SEC to conduct a tradable subscription rights offering for up to $30 million of shares of Class A common stock to its shareholders and holders of warrants to purchase common stock as of a future re- record date to be determined. The company expects to undertake and close the offering as outlined in the registration statement. We believe a rights offering allows us to balance the need to raise capital while remaining cognizant not to dilute existing shareholders. We believe this is an opportunity to participate for all shareholders and to raise needed capital. With that, thank you, and I will turn the call over to Wa'el.
Thank you, Lisa. As you have heard today, we are making steady progress in advancing Lomecel-B across three indications. We are looking forward to highlighting the potential of these assets in the HLHS and our Key Opinion Leader webinar next week. As Natalia has mentioned, it's August 16th, Wednesday. I would like to open the call now for questions. Operator, please open the line for our covering analysts.
At this time, we will be conducting a question and answer session. If you would like to ask a question, please press star 1 on your telephone keypad. A confirmation tone will indicate that your line is in the question queue. You may press star 2 if you would like to remove your question from the queue. For participants using speaker equipment, it may be necessary to pick up your handset before pressing the star keys. One moment please, while we poll for questions. Our question comes from (Crosstalk)Michael Albeniz from ROTH MKM. Please proceed with your question.
Hey, guys. Thank you for taking my question here. I guess, Than, I'd like to just get your take on the FDA decision for Leqembi. Obviously, this was a disappointment for the space, but given that you're both in rare pediatric disease, does this do anything to inform your future development for Lomecel-B in HLHS? Does it give you additional confidence in the design of Elpis II as a placebo-controlled study?
Michael, I will take the first stab in answering that question. I will have Natalia add any additional comments, or also I have Josh on the line. He can also add any additional comments. I would say that, from the beginning, we are trying to conduct our HLHS program as a pivotal trial. We are doing everything to make sure that this trial meet the FDA requirements, and hopefully, provide the necessary balance between benefit-risk ratio to accept it for filing. Having said that, there is definitely no guarantee that this is going to happen.
As you know, it's always a matter of review, FDA typically weigh in the significant medical need of the disease itself, as well as the body of evidence of the data, not just in the study that was conducted for that disease, but also for the overall body of evidence. While we were really hoping that Mesoblast get their approval on their product, you know, I can't draw a 100% parallel to the HLHS due to, one, way of conducting our trial, maybe in a different way, and second, it's a different disease state. With that, I, I will let Natalia and, and/or, Josh, to add any further comment to my comments.
Thank you very much.
One comment.
I... Okay. Go ahead, Josh.
Yes, I wanted to make a comment, and I'll turn it over to you, Natalia. Thank you. I think one of the critical aspects that need to be recognized about our ongoing HLHS trial is that it is a controlled trial, so that there is an active and best conventional care arm, which is conducted in a rigorous blinded fashion. I think that's one of the critical aspects that the FDA has commented on, that is crucial for this field. I want to emphasize that the Elpis II trial has key control group. Thank you. Natalia, please take it there.
Thank you so much. It's always the practice to use precedence, and definitely, as Wa'el indicated, it's a completely different indication. We are learning from communication between FDA and Mesoblast. Thank you.
Thank you. Yeah, thank you very much for the additional clarity. Then, I'd like to see if you have any additional insights here on what kind of a result that you would need to demonstrate for Elpis II to serve as a development?
Michael, our primary endpoint is the right ventricular ejection fraction. Again, we believe that this fall at 5% improvement. Remember, at the end of the day, it's all about benefit-risk ratio. It's, it's not really one specific measure. If we hit, then it's a home run, but I think to the overall body, survival rate could be also an added benefit, which we were encouraged from the result that I've seen from the lab on Elpis II. Both the right ventricular ejection fraction and survival rate, in addition, of course, to the safety profile of the product, will be important consideration for the agency to weigh in on that indication. Again, I'll, I'll leave it up to Natalia to add any comments.
Thank you. I have no comments.
Well, may I make a quick comment?
Sure, Josh.
Yeah. One of the unique things to understand about hypoplastic left heart that's unique from adult forms of heart failure disease, is a very clear association between ventricular function and clinical outcome. It's been well shown in studies over, going back over 25 years now. The decline in ejection fraction at Stage II surgery, is very closely correlated with the clinical outcome, and this will pose a very valuable surrogate. Our trial is designed to look, see whether Lomecel-B increases ejection fraction relative to placebo, and not placebo to say, but professional therapy, both patient groups even surgery. We think that the finding could be of great clinical value in interpreting the efficacy of Lomecel-B in the condition.
All right. Thank you very much. One more from me, I'll hop back into the queue. I'd just like to see it for Elpis II, if you could remind us of the expected timelines between completion of enrollments and Elpis, where as we're approaching that enrollment completion sometime in 2024.
Michael, Michael?
Yes.
Michael, as we announced this, we expect to be, to finish the enrollment, we're targeting hopefully mid-next year. Of course, with the software new site, there are a lot of plans to try to expedite our enrollment and the program. As you know, with rare diseases, it's hard to predict exactly when. Once we finish the enrollment, it will take 1 year after that to gather the endpoints and then close the file and provide the results from it. It should happen within 2 months after the finish enrollment, 1 year after finish enrollment.
All right. Thank you very much. I'll talk to that tail event.
Thank you.
There are no further questions at this time. I would now like to turn the floor back over to Wa'el for closing comments.
All right. Thank you. All right. Well, thank you everyone for attending our today's call. On behalf of the company and the board of directors, I would like to thank you for all your continued interest and support, and wish you a good day today. Ladies and gentlemen, thank you so much.
This concludes today's conference. You may disconnect your lines at this time. Thank you for your participation.