Terry Rosen
Analyst · BTIG
Thanks very much, Pia, and thanks to all of you on the call for listening in today. As you know, 2024 is shaping up to be an incredibly catalyst-rich year for Arcus. By the end of this year, we'll have data to support all 4 of our later-stage clinical programs: dom-zim in lung and upper GI cancers; cas in clear cell RCC; quemli in pancreatic cancer and etruma in colorectal cancer.
We'll spend most of the call today setting the stage for these upcoming data events. With over $1 billion of cash on hand, runway into 2027, partnerships with Gilead, AstraZeneca, Taiho, others, along with a very diversified pipeline, we're extremely well positioned to capitalize on these data sets and advance our potential first and also best-of-class treatments towards approval and commercialization quickly and efficiently.
Let me start with ASCO. ASCO is less than a month away. So we're almost there. We're thrilled and honored to have two oral presentations, both of which will provide strong support for our efforts and programs in the GI cancer field. Importantly, both data sets are in settings where there's limited competition and huge unmet need. These are genuine opportunities to make a meaningful difference for patients.
So first off, on Saturday, June 1, we'll have updated data from cohort A1 of the Phase II EDGE-Gastric study evaluating dom plus zim plus chemo in first-line gastric cancer. As you're aware, dom is the only Fc-silent anti-TIGIT antibody in late-stage clinical development, and we believe that the data presented to date indicate that dom may potentially have improved safety profile, when combined with chemotherapy relative to that of the Fc-enabled anti-TIGIT antibodies, when they're combined with chemotherapy.
As a reminder, we presented initial data from this cohort of EDGE-Gastric at the ASCO virtual Plenary Session in November of last year. At the time, median PFS was immature. However, we did present mature landmark 6-month PFS numbers, which you can see on Slide 16 of our corporate deck. What you can see is that 6-month landmark PFS was 77% for the overall population and 93% for the PD-L1 high population. So given that the median PFS for standard of care in the setting, ranges from 7 to 8 months, these data were obviously very, very encouraging.
At ASCO, we're very excited to be presenting mature median-PFS data. We expect the updated data will further support the potential for dom-zim to provide clinically meaningful benefit relative to the standard of care in gastric cancer. Importantly, EDGE-Gastric evaluated the same setting, in similar patient population, is our ongoing Phase III study STAR-221. So therefore, we expect these data to foreshadow what we're -- our confidence in our STAR-221 study. In that context, enrollment in STAR-221 is expected to complete by midyear.
The incredibly rapid enrollment of the study is indicative of the lack of competition in gastric cancer market and the immense need for new therapeutic options, particularly with overall survival in this patient population ranging from only 13 to 14 months in studies with anti-PD-1 antibodies in chemotherapy. We also felt that we actually achieved some tailwinds with our data presentation at the end of last year.
So putting this all together, you can infer that there's a line of sight to data and that dom-zim will have a very substantial head start over potential competitors, given there are no other anti-TIGIT antibodies in Phase III development for the same. So we think we're going to have a clear first-to-market advantage. This creates an exciting opportunity for us to be first in this setting with an addressable patient population of over 25,000 patients in the U.S. alone and 100,000 patients in the G7 countries. So this equates to the potential worldwide market of over $3 billion.
Now moving on to our second presentation at ASCO. On Sunday, June 2, we'll be presenting data from our ARC-9 study in third-line colorectal cancer. This will be the first presentation on this study. The data will be from Cohort B, which is evaluating a tumor in combination with zim, FOLFOX and bev versus regorafenib, one of the standard of care treatments for third-line colorectal cancer.
On Slide 41 of our corporate deck, you can see the study design and the conclusion criteria for this portion of the study. Patients in this cohort must have received bev unless contraindicated a prior oxaliplatin-based regimen and [indiscernible] based regimen. These are the current standard of care therapies for first- and second-line CRC. 105 patients were enrolled who were randomized 2:1 between the etruma arm and the regorafenib arm. So this is a relatively large data set.
ARC-9 also includes 2 additional randomized cohorts, which evaluated etruma plus zim plus FOLFOX and bev versus FOLFOX and bev in second-line colorectal cancer. These data are not yet matured and will be presented at a later time. Second-line setting, as you know, has a substantially longer OS. The ASCO presentation will include mature PFS and OS data with a median follow-up of over 20 months. And our data will include patients with and without liver mets. This is important since patients with liver mets tend to have a poor prognosis, and they're not always included in late-line CRC trials.
As many of you know, there are very limited options in third-line plus colorectal cancer. Patients are typically treated with regorafenib and more recently with the combination of Lonsurf and bev based on the SUNLIGHT study, which showed a PFS of 5.6 months and OS of 10.8 months in the third-line patient population. While acknowledging the limitations of cross-trial comparisons, but we all do it based on our data, which will be shared with you next month [indiscernible] combination regimen may represent a very substantial improvement over current options for patients in the third-line setting.
I also want to point out a small data set of 35 patients that was just presented in a poster at AACR, which actually captured quite a bit of interest and further supports our hypothesis that adenosine blockade enhances the immune activating benefits of chemotherapy. These data were from the MORPHEUS-PDAC study, randomized Phase Ib/II trial operationalized by Roche that evaluated our molecule etruma plus Roche's anti-PD-L1 atezo in chemotherapy versus chemotherapy alone in first-line metastatic pancreatic cancer.
We've highlighted the design on Slide 37. On Slide 38, we've shown the spider plots for both the control arm and the etruma-based regimen, which showed durable responses. In this trial, the etruma-containing arm demonstrated a meaningful improvement in both PFS and OS. And we've shown these data on Slides 39 and 40 of the corporate's deck. Specifically, the PFS hazard ratio was 0.48 and the OS hazard ratio was 0.67 with the etruma-based regimen yielding an absolute improvement in median OS survival of 4.4 months over chemotherapy alone. The median OS for the etruma containing arm was 16.5 months, very similar to what we saw in ARC-8.
Before we leave etruma, I want to highlight that now with the ARC-9 data presentation, we'll have 3 data sets presented in a very short period of time for our 2 molecules that inhibit the ATP adenosine pathway, quemli and etruma. Between ARC-8, which evaluated quemli in combination with chemotherapy in first-line pancreatic cancer, MORPHEUS-PDAC, very similar, which evaluated etruma with chemo in first-line pancreatic cancer. And now ARC-9, we have 3 independent but similar data sets, which together provide compelling evidence demonstrating that mitigating the immunosuppressive action of adenosine, combined with immunogenic chemotherapy, may prolong survival relative to that associated with chemotherapy alone.
For those of you who've been following us for a long time, keep in mind, this was the original hypothesis which drove us to the adenosine axis in the first place. So we're getting to the point where the data are matching the hypothesis. Importantly, two of these studies showed meaningful improvement in OS versus the standard-of-care control and all 3 showed substantial improvement of our historical benchmarks when adenosine blockade was combined with immunogenic chemotherapy.
Now that we've covered with what we'll be sharing at ASCO, I'd like to turn it over to Jen to discuss expectations for our HIF-2 alpha inhibitor program later this year.