Daniel M. Skovronsky
Executive Vice President, Chief Scientific and Medical Officer, and President, Lilly Research Labora at Eli Lilly and Company
Thanks, Anat. Let me start with today's exciting announcement, the positive results for tirzepatide in the SURMOUNT-2 Phase III study. Tirzepatide met the co-primary study endpoints and also hit on all prespecified key secondary endpoints. Participants with obesity or overweight and with type 2 diabetes achieved up to 16% weight loss at 72 weeks, which translates to a mean weight loss of 34 pounds.
Additionally, 86% of people taking 15-milligram tirzepatide achieved at least 5% body rate reduction. This was in line with our expectations based on our SURPASS-3 data in a similar population. With this SURMOUNT-2 data, we now have two positive Phase III trials for tirzepatide in obesity, one in patients without type 2 diabetes and one in patients with type 2 diabetes. We now look forward to completing our rolling submission to the FDA in the coming weeks.
I'll cover the SURMOUNT-2 results in more detail, but first, let me spend a few minutes providing an overview of the SURMOUNT Phase III program. The SURMOUNT program has enrolled more than 5,000 people with obesity or overweight across eight studies. On Slide 13, you can see key trial design elements for the core SURMOUNT-1 to four studies as well as the more recently announced SURMOUNT-MMO and SURMOUNT-5 studies.
Five of the six studies compare efficacy and safety of tirzepatide to placebo as an adjunct to reduced calorie diet and increased physical activity, while the most recently posted trial, SURMOUNT-5 compares tirzepatide to 2.4-milligram semaglutide.
As a reminder, SURMOUNT-1 was designed to evaluate treatment with tirzepatide compared to placebo for people without type 2 diabetes with obesity or overweight with at least one comorbidity. And it delivered up to 22.5% mean body weight reduction. SURMOUNT-2, which we're reporting today, evaluated treatment with tirzepatide compared to placebo for people with obesity or overweight and type 2 diabetes.
SURMOUNT-3 will provide data on maximizing weight loss following an intensive lifestyle program and SURMOUNT-4 evaluates maintaining weight loss. SURMOUNT-5 is an open-label trial that will enroll 700 adults who have obesity or overweight with weight-related comorbidities without type 2 diabetes and will compare the efficacy and safety of tirzepatide to semaglutide 2.4-milligrams. Finally, SURMOUNT-MMO is our Phase III morbidity and mortality and obesity study to evaluate improved outcomes for patients with obesity. We expect the next two studies, SURMOUNT-3 and SURMOUNT-4 to read out later this year, while SURMOUNT-5 is anticipated to complete in the first half of 2025. SURMOUNT-MMO, as an outcome study, will take several more years to complete.
On Slide 14, you can see the first co-primary endpoint in the SURMOUNT-2 study where tirzepatide 15-milligram delivered 15.7% mean body weight reduction in adults with type 2 diabetes with obesity or overweight. With a baseline weight across the study of 222 pounds, tirzepatide treatment led to a mean body weight reduction of 34 pounds on the 15-milligram arm of the study. We're also very pleased to see how well the 10-milligram tirzepatide performed with a 13.4% mean body weight reduction, also at 72 weeks for the efficacy estimand. Results for the treatment regimen estimand were similar to the efficacy estimand and are detailed in this morning's SURMOUNT-2 press release.
Moving to Slide 15. Tirzepatide achieved the second co-primary endpoint of achieving at least 5% body weight reduction. SURMOUNT-2 showed up to 86.4% of patients achieved this level of weight reduction at 72 weeks, again, using the efficacy estimand. This is compared to 30.6% of patients on placebo as an adjunct to diet and exercise. Furthermore, over half of all participants in the 15-milligram treatment arm achieved at least 15% weight loss.
It has been previously observed in incretin obesity trials that weight loss in a type 2 diabetes population is less than weight loss seen in a non-type 2 diabetes population, a finding consistent with the results we've now reported from the SURMOUNT-1 and SURMOUNT-2 trials. The average weight reductions reported in the SURMOUNT-2 trial in patients with type 2 diabetes range from 7% to 8% less than those seen in SURMOUNT-1, which was an exclusively non-type 2 diabetes population.
There are a number of potential mechanisms that may explain this effect, including the weight gain-promoting effects of some classes of anti-hyperglycemic medications used in the treatment of type 2 diabetes, improving insulin sensitivity with tirzepatide treatment, gender differences between 2 populations and diminished caloric loss effects of glucosuria. These differences manifested as we expected, and the SURMOUNT-2 top line results represent the most robust weight loss seen in a Phase III pharmacological clinical trial consisting entirely of type 2 diabetes patients with obesity or overweight, and we are highly pleased with these results.
Moving to Slide 16. You can see the safety profile from the SURMOUNT-2 study. Tirzepatide was well tolerated in the study participants with the overall safety and tolerability profile similar to incretin-based therapies approved for treatment of obesity.
As in SURMOUNT-1 and the SURPASS program, the most commonly reported adverse events were GI-related, were generally mild to moderate in severity and usually occurred through dose escalation. Treatment discontinuation rates due to adverse events were 3.8% and 7.4% for the 10- and 15-milligram tirzepatide treatment arms, respectively, compared to 3.8% for placebo. The overall treatment discontinuation rates were 9.3% and 13.8% in the 10- and 15-milligram tirzepatide treatment arms compared to 14.9% for placebo.
We look forward to sharing more data from SURMOUNT-2 at the American Diabetes Association meeting in June and to submitting the results for publication in a peer-reviewed journal. Obesity is a widespread and chronic disease in need of more effective treatment options. The FDA Fast Track designation that tirzepatide received for obesity reflects the seriousness of the condition and the substantial unmet medical need. With impressive trial results now in hand for SURMOUNT-2 and SURMOUNT-1 studies, we look forward to completing our rolling submission to the FDA for tirzepatide for the treatment of adults with obesity or overweight with weight-related comorbidities in the coming weeks.
With respect to regulatory action in Europe, as Dave mentioned, we have already completed our submission to the EMA for chronic weight management indication. The EMA submission was initiated based on the results from the SURPASS trial program in type 2 diabetes and the SURMOUNT-1 Phase III trial in obesity. We expect to have a European Commission decision in the first half of 2024. In addition to all the work on tirzepatide for obesity, we also disclosed earlier this month on clinicaltrials.gov the initiation of a bioequivalent study to compare the pharmacokinetics of tirzepatide administered using the existing auto-injector device and a new test device. We expect to work on tirzepatide and other injectable incretins for a long time. And we intend to explore different presentations for these medicines to meet our goal of bringing the benefits to as many patients as possible as quickly as possible.
Moving on from tirzepatide to the rest of the portfolio. Slide 17 shows select pipeline opportunities as of April 24, and Slide 18 shows potential key events for the year. There have been several important developments since our last earnings call, and I'll cover these by therapeutic area. Continuing within diabetes and metabolic disease. Earlier this month, we began recruiting for the first Phase III clinical trial for orforglipron, our oral GLP-1 non-peptide agonist.
This ACHIEVE-4 trial is an open-label study of orforglipron compared with insulin glargine in adults with type 2 diabetes and obesity or overweight at increased risk for cardiovascular events. This is the first in what will be a broader series of studies for orforglipron. It is the largest and longest trial in the program, which is why we chose to initiate this trial first. Enrollment is now underway and we expect patient dosing to recur shortly, after which orforglipron will be placed with our Phase III assets on the summary slide. You'll also see we have advanced our Relaxin long-acting molecule to Phase II development for treatment of heart failure.
Shifting to immunology. It was a quarter of mixed progress for mirikizumab, our IL-23 P19 inhibitor. We were pleased with the approval in late March in Japan for mirikizumab under the brand name Omvoh for adults with moderately to severely active ulcerative colitis. A few days later, we were similarly pleased with the positive CHMP opinion from the EMA. However, regarding mirikizumab's regulatory path in the United States, we announced earlier this month that we received a Complete Response Letter from the FDA. The letter did not cite any concerns regarding the safety or efficacy profile of mirikizumab but focused exclusively on certain aspects related to the proposed commercial manufacturing of mirikizumab.
We remain confident mirikizumab's Phase III data and its potential to help people with ulcerative colitis. We look forward to working with the FDA to address the manufacturing questions in order to achieve our goal of bringing mirikizumab to patients in the U.S.
Also in our late phase immunology portfolio, we completed the regulatory submission in Japan for lebrikizumab for patients with atopic dermatitis. Moving earlier in our immunology pipeline, during last month's American Academy of Dermatology meeting, we shared data from the single-dose Phase II trial for eltrecabart, our CXCR1/2 antibody in patients with hidradenitis suppurativa. The data showed good tolerability and clear separation between eltrecabart and placebo, along with a reduction in abscesses and nodules, reflecting reduced disease activity.
Lastly, in immunology, we've removed respegaldesleukin from our pipeline. In February, following the top line data announcement from the Phase II study in systemic lupus erythematosus, we informed our partner, Nektar Therapeutics that we do not intend to advance the asset into Phase III development.
Moving on to neuroscience. Last month, we announced that our last active solanezumab trial, the antiamyloid in asymptomatic Alzheimer's disease study or A4 study did not meet its primary or secondary endpoints. The A4 study was conducted through an innovative public-private partnership, and we were thankful for the time and effort of the clinical study staff, participants and study partners. This study formally concludes our clinical development of solanezumab. The A4 results, while disappointing, were not a surprise, given the advancements in our understanding of Alzheimer's disease since the study initiated almost 10 years ago.
Solanezumab only targets soluble amyloid beta and does not clear plaque. Donanemab and remternetug, on the other hand, have been specifically designed to bind to and clear amyloid plaque, and we now understand that substantial plaque clearance is required in order for anti-amyloid drugs to show clinical efficacy. Accordingly, we were pleased to share new data for donanemab and remternetug during the International Conference on Alzheimer's and Parkinson's disease in late March. For donanemab, we shared data from our TRAILBLAZER-EXT, a Phase II long-term follow-on study of TRAILBLAZER-ALZ. While study limitations include a relatively small number of patients, the data showed encouraging trends and the longer-term effects on amyloid and tau levels and clinical progression. We also disclosed the trial design and objective for TRAILBLAZER-ALZ 6, a Phase IIIb study to expand the science and understanding of ARIA in relationship to amyloid lowering through imaging and blood-based biomarkers in different dosing paradigms. This study will leverage enhanced MRI sequences as well as blood-based biomarkers and other patient characteristics that may predict ARIA. And we'll investigate the effect of different dosing regimens on the frequency and severity of ARIA. Of course, we expect the next key milestone for donanemab will be later this quarter when we obtain the results for our confirmatory Phase III TRAILBLAZER-ALZ 2 trial. We look forward to sharing these results and to advancing the regulatory process for donanemab assuming positive data from this trial.
This quarter, we also shared the first clinical data from remternetug from a Phase I multiple ascending dose study, which highlighted the potential speed and depth of amyloid plaque lowering in patients with Alzheimer's disease. These data on amyloid clearance, safety and tolerability supported our decision to move this asset into Phase III, and we look forward to sharing further updates as the program progresses.
You'll also notice we have a number of developments in our early-stage neuroscience portfolio with a Phase II entry for our GBA1 Gene Therapy asset in the Gaucher disease type 1 indication along with 2 Phase I pain asset entries and 1 Phase II pain asset discontinuation.
Shifting now to oncology. Just yesterday, Jaypirca received a positive opinion from the CHMP for the treatment of relapsed or refractory mantle cell lymphoma. In early March, the FDA approved an expanded indication for Verzenio for the adjuvant treatment of adult patients with HR-positive HER2-negative node positive early breast cancer at high risk of recurrence. High-risk patients can now be more easily identified with the removal of the Ki-67 score requirement for patient selection.
Moving earlier in our oncology pipeline. We presented data from our Phase I study of our KRASG12C inhibitor as part of the AACR meeting last week. These data show promising efficacy and the potential for a differentiated safety profile in combination with pembrolizumab. We're working on finalizing dose selection for our drug in combination with pembrolizumab.
And at AACR, we also showed data from CYCLONE 1, a single-arm unblinded study, which was the first to investigate Verzenio in prostate cancer. This early study informed the design of our CYCLONE 2 adaptive Phase II/III trial, which last year cleared our preset threshold to advance to Phase III and for which we expect to read out as soon as late this year. Q1 was another busy and productive quarter for pipeline advancement at Lilly.
Now I'll turn the call back to Dave for closing remarks.