Good day, ladies and gentlemen. Welcome to the Altimmune Inc. First Quarter 2023 financial results conference call. At this time, all participants are in a listen-only mode. Later, we will conduct a question-and-answer session, and instructions will follow at that time. To ask a question during the session, you will need to press star one one on your telephone. As a reminder, this call is being recorded. I would now like to introduce your host for today's conference call, Rich Eisenstadt, Chief Financial Officer of Altimmune. Rich, you may begin.
Thank you, Gigi. Good morning, everyone. Thank you for participating in Altimmune's first quarter 2023 financial results and business update conference call. Members of the Altimmune team joining me on the call today are Vipin Garg, our Chief Executive Officer; Scot Roberts, our Chief Scientific Officer; and Scott Harris, our Chief Medical Officer. Following the prepared remarks, we will hold a question-and-answer session. A press release with our first quarter 2023 financial results was issued this morning and can be found on the investor relations section of the company's website. Before we begin, I would like to remind everyone that remarks about future expectations, plans, and prospects constitute forward-looking statements for purposes of safe harbor provisions under the Private Securities Litigation Reform Act of 1995. Altimmune cautions that these forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those indicated.
For discussion of some of the risks and factors that could affect the company's future results and operations, please see the risk factors and other cautionary statements contained in the company's filings with the SEC. I would also direct you to read the forward-looking statement disclaimer in our press release issued this morning and now available on our website. Any statements made on this conference call speak only as of today's date, Thursday, May 11th, 2023. The company does not undertake any obligation to update any of these forward-looking statements to reflect events or circumstances that occur on or after today's date. As a reminder, this conference call is being recorded and will be available for audio replay on Altimmune's website. With that, I will now turn the call over to Dr. Vipin Garg, Chief Executive Officer of Altimmune.
Thank you, Rich. Good morning, everyone. We appreciate you joining us today for a discussion of our first quarter 2023 financial results and business updates. We continue to advance our lead product candidate, pemvidutide, a GLP-1/glucagon dual receptor agonist in development for both obesity and NASH. Late last year, we announced compelling 24-week data from our trial in subjects with NAFLD , and we plan to initiate the IMPACT phase II-B NASH trial midyear 2023. We believe that the effects of pemvidutide on liver fat are class-leading. We also believe that pemvidutide is the only NASH candidate in development that combines robust reductions in both liver fat and body weight. This is extremely important because NASH patients suffer not only from the complications of liver disease, but also from the underlying problem of obesity, a principal driver of NASH.
Scott Harris will provide more details on the IMPACT of trials shortly. With regards to obesity, we look forward to reporting top-line 48-week weight loss data from our phase II MOMENTUM Obesity trial in the fourth quarter of this year. The MOMENTUM interim results of 160 subjects reported earlier this year showed weight loss of 10.7% at the 2.4 mg dose and 9.4% at the 1.8 mg dose, compared to 1% weight loss in subjects receiving placebo after only 24 weeks. These robust reductions in body weight, together with the effects of pemvidutide on serum lipids and blood pressure, suggest that pemvidutide has the potential to be an important treatment option for patients with obesity, especially individuals with NAFLD and dyslipidemia.
Enrollment in the phase II clinical trial of HepTcell in chronic hepatitis B is now complete. We expect to have a data readout in the first quarter of 2024. Recall that this trial is designed to show evidence of antiviral effects against HBV and establish its role in combination therapy for the treatment of this important disease. We're excited about the progress of pemvidutide and HepTcell and the upcoming results of these ongoing trials. With that, I'll now turn the call over to our Chief Medical Officer, Dr. Scott Harris, to discuss our clinical plans. Scott?
Thank you, Vipin. Good morning, everyone. First, let me start by reviewing the clinical plans for our IMPACT phase II-B NASH trial. This biopsy-driven NASH trial will be conducted at approximately 60 sites in the U.S. with Dr. Stephen Harrison, Medical Director of Pinnacle Research and Adjunct Professor of Medicine, University of Oxford, serving as principal investigator. To be eligible for study participation, subjects will be required to have a BMI of at least 27 kg per meter squared.
A liver fat content of at least 8% as measured by MRI-PDFF, a NAFLD activity score of at least four on a pretreatment biopsy, and either F2 or F3 fibrosis. At least 50% of the subjects will be required to have F3 fibrosis. Subjects both with and without diabetes will be enrolled. In our two earlier NAFLD trials, the 2.4 mg dose did not materially improve liver fat reduction or cT1 response over the 1.8 mg dose. The 2.4 mg dose will not be evaluated in this trial. Subjects will consequently be treated with pemvidutide 1.2 mg, pemvidutide 1.8 mg, or placebo.
We are planning for approximately 190 subjects to be enrolled in the IMPACT trial in a 1:2:2 randomization scheme, with subjects stratified for fibrosis stage in the presence or absence of diabetes. Therefore, approximately 36 subjects are expected to receive pemvidutide 1.2 mg, 76 subjects pemvidutide 1.8 mg, and 76 subjects placebo. The primary endpoints of the NASH IMPACT trial will be dual endpoints of achieving either NASH resolution with no worsening of fibrosis or fibrosis improvement with no worsening of NASH, with the primary treatment comparison being the 1.8 mg dose versus placebo. Secondary endpoints will include weight loss, liver fat reduction by MRI-PDFF, cT1 response rate, serum lipids, and non-invasive biomarkers of disease.
All endpoints will be assessed at week 24 of treatment. Subjects will continue to be dosed and followed for an additional 24 weeks to a total of 48 weeks for safety and additional biomarker responses. Our algorithm for biopsy reading and adjudications leverages the experience of other recently completed NASH trials, which we anticipate may optimize the likelihood of pemvidutide achieving robust endpoint responses. A plan has been developed to correlate non-invasive tests with NASH resolution and fibrosis improvement biopsy endpoints and to commence discussions with FDA about the use of these biomarkers as primary endpoints in phase III. We remain on target for the trial to commence mid-year and to report top-line results in the first quarter of 2025. Dose reduction will be made available to subjects who experience GI intolerance, though pemvidutide was well tolerated in our two previous trials in subjects with NAFLD.
Now let me talk about the phase II MOMENTUM trial of pemvidutide in obesity. The trial was designed to enroll approximately 320 subjects without diabetes but with obesity or overweight with at least one comorbidity. Dr. Louis Aronne , from Weill Cornell Medical School, a leading authority in obesity and obesity clinical trials, is serving as the principal investigator. Subjects were randomized 1 : 1 : 1 : 1 to 1.2 mg, 1.8 mg, 2.4 mg pemvidutide or placebo, administered weekly for 48 weeks in conjunction with diet and exercise. A pre-specified interim analysis was performed when 160 subjects completed 24 weeks of treatment.
Weight loss of 10.7% at the 2.4 mg dose and 9.4% at the 1.8 mg dose was achieved, compared to 1% weight loss in subjects receiving placebo. Approximately 50% of subjects achieved at least 10% weight loss, and approximately 20% of subjects achieved at least 15% weight loss by week 24 at the 2.4 mg and 1.8 mg doses. The adverse event discontinuation rate at the 2.4 mg dose was higher than observed in our four prior trials with pemvidutide, but similar to the adverse event discontinue rates in similar phase II trials of other incretin-based agents. We believe that the GI adverse discontinuation rate can be mitigated to low levels in future trials of pemvidutide through the use of dose reduction.
We look forward to our top-line results from our MOMENTUM trial in the fourth quarter of this year. We expect to see continued weight loss beyond the double-digit levels noted at our 24-week interim analysis. Other top-line readout parameters will include adverse events, vital signs, serum lipids, glucose control, and study discontinuations. Also, as we previously announced, we have completed the enrollment in our phase II multicenter clinical trial of HepTcell in patients with chronic hepatitis B. Chronic hepatitis B continues to represent a serious unmet need in the U.S. and worldwide and represents a significant commercial opportunity. The HepTcell trial was designed to enroll approximately 80 subjects with an active chronic hepatitis B and low hepatitis B surface antigen or HBsAg, and to evaluate the efficacy of HepTcell monotherapy as measured by a reduction in HBsAg and other virological markers of infection.
We expect to announce the results of this trial in the first quarter of 2024, once all subjects complete the six-month treatment period. It is generally believed that an effective therapy for chronic hepatitis B will require both direct-acting antivirals and immunotherapy. We believe that HepTcell could be combined with novel direct-acting antivirals in this treatment strategy. I'll now hand the call over to Rich Eisenstadt to give an update on our third-quarter financial results. Rich?
Thank you, Scott, and good morning again. For today's call, I'll be providing a brief update on Altimmune's first-quarter 2023 financial and operating results. More comprehensive information will be available in our Form 10-Q to be filed with the SEC later today. Altimmune ended the first quarter of 2023 with approximately $165.8 million of cash equivalents and short-term investments, compared to $184.9 million at the end of 2022. Research and development expenses were $17.2 million in the first quarter of 2023, compared to $15.1 million in the same period in 2022.
Approximately $10.8 million of this total for the first quarter of 2023 were direct expenses for the conduct of our clinical programs, including $8.7 million in direct costs related to development activities for pemvidutide and $2.1 million in direct costs related to development activities for HepTcell. General and administrative expenses were consistent period-over-period at $4.5 million and $4.4 million for the three months ended March 31st, 2023 and March 31st, 2022 respectively. Interest income was $1.7 million for the three months ended March 31st, 2023, and was negligible in the three months ended March 31st, 2022.
Net loss for the three months ended March 31st, 2023, was $20.1 million or $0.40 net loss per share, compared to net loss of $19.4 million or $0.44 net loss per share for the first quarter of 2022. We estimate that our existing cash funds us through the 24-week biopsy results from our IMPACT phase II-B NASH trial expected in the first quarter of 2025. Our financing also funds completion of the 48-week MOMENTUM trial and the HepTcell trial. Our current cash projection includes no funding for the initiation of a phase III obesity campaign, which would only commence with a partner. I will now turn it back over to Vipin for his closing remarks. Vipin?
Operator, that concludes our formal remarks. We would like to open the lines to take questions. Could you please instruct the audience on the Q&A procedure?
Thank you. As a reminder, to ask a question, please press star one one on your telephone and wait for your name to be announced. To withdraw your question, please press star one one again. Our first question comes from the line of Seamus Fernandez from Guggenheim Securities.
Great. Thanks for the question. Rich, in your remarks, you commented that forward advancement into phase III obesity would require a partner. Can you just help us understand how, you know, Vipin and Rich, if you can both help us understand how you're thinking about a potential partner here, given sort of the overlapping dynamics of NASH and obesity.
You know, separately, just maybe remind us what you're hoping to see in the broader clinical data set from the MOMENTUM study when we receive that at 48 weeks, and the importance of those data to a potential partner, what you believe partners are looking for in that data set or potential partners might be looking for in that data set to move forward. Thanks.
Good morning, Seamus. Thank you for the question. As you know, both NASH and obesity, they're both large markets and we believe will benefit from having a partner for both of these indications. Our goal is to have a partner for the phase III initiation by the time we are ready to start phase III for obesity. In parallel, we'll also discuss with partners of joining forces with regards to NASH as well. Ultimately, our goal is to have a partner that has the resources and can bring value to both of these indications, because ultimately, in order to market a drug for both of these indications, we'll need a partner. We will explore a partnership across both of these assets.
If it turns out that initially the partnership is only centered around obesity with a downstream prospect of including the NASH as well, we will explore all of those options. There are multiple ways of doing these partnerships. We have embarked on our phase II-B plan for NASH, that data will become available in due course. All of those items will sort of play a role in terms of ultimately designing the optimal structure for a partnership around both of these indications. With regards to the data, as you know, we've announced the 24-week data. Again, our goal has been to engage in partnership discussions on the back of that data. Clearly, partners will also be looking for the 48-week data, as we are.
At least some partners would wanna see the 48 week data. We expect to continue to show additional weight loss, I think that would be very important as we go into partnership discussions later this year.
Great. Just wanted to reconfirm the timing of the NASH 24-week result. I think previously you'd stated that you anticipate having those results sometime in the first half of 2025. Just wanted to see, you know, as you're getting closer to the initiation of the phase II, how those timelines are continuing to shake out. I'll jump back in the queue. Thanks.
Yeah, no, the timeline is looking good. We think we can get those results in the first quarter of 2025, and that's what we are guiding to at this point. We feel very comfortable saying that the trial should start here in next few weeks or a few couple of months. Basically based on our analysis of the time it will take to enroll these subjects and treat them, first quarter of 2025 would be in a reasonable timeline.
Great. Thank you.
Thank you. One moment for our next question. Our next question comes on the line of Yasmeen Rahimi from Piper Sandler.
Hi, good morning, team. Thank you so much for all the details and also the really outstanding NASH trial design. Few questions for you. I think the first one is along with what Seamus was asking, Mike. In regards to discussions with partners in regards to the profile of survodutide, do you have a feeling for what type of weight loss do they wanna or see as competitive at week 48? That's question one. Question two is, could you maybe speak a little bit about the nature of the biopsy handling in the study? Will you have two readers? Will they be read in pairs? Any sort of logistical details around the reading.
The third question is if you could just comment on what NITs are being utilized at baseline for screening the patients and creating a homogeneous population. I'll jump back right into the queue. Thank you again for taking my questions.
Yeah, good morning, yes, and thank you for the question. I'll take the first part of your question, and then I'll turn it over to Scott Harris to talk about the NASH patient population. In terms of weight loss, we've always maintained that a weight loss in mid-teens would be competitive. In our discussions, we're finding, you know, that's basically where the universe is in terms of at 48 weeks, if we are in that mid-teen range, that would be a competitive weight loss. Once again, I would like to emphasize that it's not just about weight loss. There are multiple parameters here that are going to play a role.
I mean, we believe that having this combination of GLP-1 and glucagon brings a unique aspect or a unique attribute to the product, where the product will be much well-suited for obese patients with high liver fat content and dyslipidemia. That's a distinct patient population from, you know, people having diabetes and obesity. I think as this field develops, there will be multiple segments. In fact, the number of patients with dyslipidemia and obesity is higher than patients with diabetes and obesity. We think there's significant opportunity there with mid-teen weight loss, but having the benefit of liver, direct impact on liver and liver fat reduction. Scott Harris, do you want to address the second part of the question?
Sure. Good morning, Yasmeen. Regarding the biopsy readout procedure, we've benefited greatly from the experience of other companies and, really, comparing across the readout methodologies. We think we have a really robust plan in place based on that experience. We've not made those