Hello, everyone. My name is Øystein Rekdal, and I am the CEO at Lytix Biopharma. Welcome to this webinar, where we will present the interim data from our ATLAS-IT-05 study that were presented today at the European Society for Medical Oncology Congress in Madrid, Spain. With me today, I have Graeme Currie, our Chief Development Officer, that will present the encouraging data, interim data, and some general update on the ongoing study. After that, I will give you a short update on our other programs before we end the webinar with a Q&A session.
And please follow the instruction at the webinar site for asking question. But first, a brief introduction to Lytix. Lytix is a listed Norwegian company with a technology platform derived from world-leading research on host defense peptides, and with molecules that address the major challenge in current immunotherapy. Currently, our lead component, LTX-315, in test, is tested in two phase II studies, one in basal cell carcinoma, run by our partner Verrica Pharmaceuticals, and the ATLAS-IT-05 study in melanoma, which is the topic of today's webinar.
Our molecules can work in several different cancer indication, either as mono or combination therapy, and the versatility of our technology platform opens for several types of commercial avenues. I will with this hand over to Graeme, who will present and explain the interim data from the ATLAS-IT-05 study.
Thank you, Øystein. We can move to the next slide, please. I'm pleased today to present the data from a poster that was presented at the ESMO 2023 meeting that is ongoing in Madrid today. The presentation was given by our lead author, Professor Stéphane Dalle, who's one of the highest recruiters in the ongoing trial. We move to the next slide, please. LTX-315 has a unique mode of action that results in effective release, potent immunostimulants that are able to induce an immune response on top of pembrolizumab.
Direct injection into an immunologically cold tumor targets the mitochondria and causes release of tumor antigens, which are then trafficked to dendritic cells or other professional presenting cells, which are then able to enhance the T cell response to those novel tumor antigens, which then return to the tumor, enabled to induce killing. We can move to the next slide. These are just the RECIST version 1.1 definitions. I won't present this slide, but just as a, these are here as a record, so you can reflect on the terms, complete response, which is all tumor gone, partial response with a greater than 30% decrease of target lesions, and progressive disease is where the greater than 20% of the target lesions are growing.
Objective response rate and disease control rate are also found on this slide. If we move to the next slide. As the study objectives and endpoints are summarized on this slide, our objective is to evaluate the initial efficacy and safety of intratumoral LTX-315 in combination with pembrolizumab, a checkpoint inhibitor, in patients with Stage IIIb and Stage IV M1b to Stage IV M1b melanoma, who progressed on or after prior treatment with a PD-1 or a PD-L1 inhibitor. Our primary efficacy endpoint is objective response rate, and we also looked at disease control rate.
Secondary efficacy endpoints, objectives included regression of injected lesions assessed by CT or ultrasound measurements by investigators, and we also looked at the incidence and severity of adverse events related to LTX-315. Next slide, please. The study was designed where in two phases. In phase A, LTX-315 was dosed on seven dosing days, and on each dosing day, up to eight injections could be delivered. In parallel, they were administered pembrolizumab at 200 mg on day one and day 22. After completion of phase A, phase B allowed patients to continue on pembrolizumab at a dose of 400 mg every six weeks until disease progression or completion of 24 months therapy.
CT scans are recorded every nine weeks, which is consistent with clinical practice. Next slide, please. I mentioned earlier in the title, as we look at key inclusion and exclusion criteria, these patients range from stage IIIb to stage IV M1b unresectable melanoma, but they had confirmed disease progression on or after prior treatment with a checkpoint inhibitor. They must have had less than or equal to three prior lines of systemic treatment, or all patients had actually had prior surgery, and they needed to have at least one superficial tumor lesion accessible for injection.
These were a group of patients who had very advanced disease, and they were either resistant or refractory to prior standard of care treatments. Everybody was refractory to a checkpoint inhibitor, and in addition, some of these patients had also failed BRAF/MEK inhibition. These patients currently have no approved treatment and have limited treatment options. We move to the next slide. This is a presentation of our first data snapshot, which is still quite early in the trial.
There are 20 patients included in the safety analysis set, and 14 of these were eligible to be included in our efficacy analysis set, which meant that they'd received drug and also had a baseline and at least one post-baseline scan. The cutoff for this data snapshot was 13th of September 2023. The median duration of follow-up was still quite limited, being 15 weeks, so just getting to that stage where we'd had that second scan. Next slide. If we look at the overall patient population, the majority of the patients had very advanced melanoma with poor prognostic baseline factors.
60% had Stage IV disease and a relatively high tumor burden. 40% of these patients had received two or more prior anti-cancer treatments, some of these failing double checkpoint therapy, and as I stated earlier, some patients who had failed BRAF/MEK inhibition. Some of these BRAF/MEK inhibition patients are known to progress really quite rapidly. 55% of the patients had increased LDH levels at baseline. This is known to be a poor prognostic factor. We move to the next slide, please. At this early time point in the study, we had 1 partial response that was unconfirmed.
That response has subsequently been confirmed at a follow-up scan. We had good disease control rate, with 43% of patients remaining under disease control. And just to remind everybody, these patients had been progressing on the prior therapy, and some of them had progressed through multiple lines of therapy. We move to the next slide. As we look at the RECIST target lesions, so these are lesions followed by CT scan, not the lesions that are directly injected. And as you can see, we saw good stabilization of disease and a number of patients who had reduction in tumor burden.
These patients with the arrows here are still ongoing in the study, so we will still have further updates on this, but 43% of patients are under disease control at the current time. Next slide, please. We looked specifically in the response in the injected lesions. Nine out of the 21 lesions that we had data on showed 100% complete regression by CT scan after the start of treatment. Partial responses aren't formally connected in this assessment by CT. We will continue to look at this data as we move through the study, but we show here a nice example of a patient who had a lesion, a very obvious lesion.
After day post LTX-315 injection, you see nice evidence of necrosis, and by day 43, that lesion had been completely removed. We move to the next slide. This is another case example of a patient who had multiple large tumor lesions on the right forearm that were injected with LTX-315. We show evidence here at screening. At day 43, very clear signs of necrosis and regression of the injected tumor lesions, and a good healing of the skin. Note, this patient was technically classified as a progressive disease patient because they had emergence of a small lesion on their index finger.
But the patient continues on therapy, and we are hoping that they may continue to do well. Next slide, please. Now turn to safety, and as we look at safety, not unsurprisingly, injection site pain was reported in the majority of patients, but it tended to be mild, moderate, and self-limited. There was no increase in immune-related adverse events, and no severe or lethal adverse events have been reported to date. The safety profile appeared easily manageable in clinical practice. Next slide. We'll dig more a little into one of the cases.
This was a patient with a clinically relevant local and systemic response. The patient was a 75-year-old male with stage IV M1a nodular melanoma, which was BRAF positive. The patient had multiple mets in lymph nodes and gluteal muscle at baseline. In a prior treatment setting, they'd received Nivolumab in the adjuvant setting, and they'd also received BRAF/MEK inhibition when they had metastases. They were treated with a total of 20 injections of LTX-315 in four lesions on prescribed dosing days, and they had two cycles of pembro in phase A and three cycles in phase B.
The RECIST target lesion was in the left gluteal muscle. They are classified as partial response as the best overall response at the cutoff date, with a RECIST target lesion shrinkage of 89%. We move to the next slide, please. Here we see the CT scan with a target lesion being seen on the right of the CT scan with a baseline size of 28 millimeters. Day 43, there seemed to be some small amount of shrinkage, but by day 169, we saw significant shrinkage, with the lesion down to 3 millimeters. As we... That was just the one lesion I'm showing you there.
If we look at all the injected lesions, this patient showed complete regression of all injected lesions. We move to the next slide, please. Case number two was a 77 year old female patient with Stage IV M1a melanoma, prior treatment with Nivolumab in the metastatic setting, but disease progression whilst on treatment. The patient received 30 injections of LTX-315 in one lesion on six prescribed dosing days, and they've completed two cycles in phase A and four cycles in phase B of pembrolizumab. The RECIST target lesions were in the lymph node and skin.
Shrinkage of RECIST target lesions by 36%, but again, this patient showed appearance of a small new lesion, so not assessed as a partial responder by RECIST 1.1 criteria. We move to the next slide. As you can see here, when we look at the non-injected lesions, we are seeing shrinkage in those lesions, the main lesion in the skin and then two lymph nodes. The appearance of that lymph node in the middle there was why the patient is currently classed as unconfirmed progressive disease. We will continue to follow this patient.
Next slide, please. In a prior version of the protocol, we were allowed to enroll beyond melanoma patients, and an acinic cell carcinoma patient was enrolled under that prior version of the protocol. This was a 62-year-old female with stage IV acinic cell carcinoma, and acinic cell carcinoma is known to not respond well to checkpoint therapy. The patient had multiple metastases in bone, peritoneum, breast, adrenal gland, and lung, so extensive disease. They had not received prior treatment with a checkpoint inhibitor.
They were treated on seven dosing days with LTX-315, and two cycles in phase A and 15 cycles in phase B with pembrolizumab. Partial response was considered the best overall response for this patient, and they've had a very durable response, with the RECIST lesion shrinking completely and complete regression in four out of 7 RECIST non-target lesions. This patient continues on treatment and is rapidly approaching completing two years of therapy. We move to the next slide. As you can see here in the target lesion, a response was seen around day 106 and has been maintained for over one and a half years.
These patients, as I mentioned before, tend to respond very poorly to monotherapy with a checkpoint inhibitor, response rates less than 5%. Move to the next slide, please. In conclusion, based on this early data snapshot, the confirmation regimen demonstrates preliminary signs of tumor shrinkage and prolonged stabilization of disease in this heavily pretreated group, group of PD-1, PD-L1 refractory metastatic melanoma. Enrolled patients generally had poor prognostic factors, and some patients had also failed BRAF/MEK inhibition.
The efficacy signal is encouraging, with a disease control rate of 43%, and to date, one patient is classified as achieving a partial response, which I mentioned earlier, was confirmed. There is evidence of tumor shrinkage in both the injected and in non-injected lesions. We will continue to follow these patients, as the study evolves, and we will report future updates. But at this time, we can say that the intratumoral treatment of LTX-315 is well-tolerated, with generally mild to moderate adverse events. We look forward to sharing further updates in a future presentation.
I'll now hand back over to. Oh, sorry. Before I hand back over to Øystein, just to give an update on next steps in this trial. So this is the first interim readout at ESMO. We will have full top-line data on patients in early 2024. We're looking to expand our data and enroll, barring amendment, to expand this cohort, which would then allow a presentation of that data in the first half of 2025. Final readouts from this study will really depend on how long patients are treated. Some of these patients can go out to 24 months. So we will give firmer guidance as that, as the trial continues to progress. On that, I'll hand back over to Øystein.
Thank you, Graeme. In this ATLAS-IT-05 study, we are recruiting late-stage melanoma patients, as you have been told, with poor prognosis and often with a weakened immune system. Since immunotherapies still have shown a certain degree of efficacy in metastatic cancer, there is a general expectation that moving the use of immunotherapy to patients with earlier-stage cancer could result in an even stronger immune response. Therefore, we are also enthusiastic to start a neoadjuvant study in early-stage melanoma patients in collaboration with the Oslo University Hospital, Radiumhospitalet.
In this study, LTX-315 will be added to standard of care treatment, the immune checkpoint inhibitor pembrolizumab, before surgery. This will be an investigator-driven study led by Dr. Henrik Jespersen, who is head of melanoma group at Radiumhospitalet. The study is planned to start early 2024, and positive results in this setting could potentially open for neoadjuvant studies in additional cancer indication. As earlier announced, Lytix, LTX-315, has shown very promising efficacy in the ongoing phase II study in basal cell carcinoma, with complete clearance obtained in tumors that were injected with the highest dose of LTX-315 tested in this study.
The study is led by our partner, Verrica Pharmaceuticals, and with these early positive results, the study expected to be completed mid-2024, which is earlier than initially anticipated. Today, the most common treatment of basal cell carcinoma is surgery, which can both be painful and cause scar and destruction of healthy tissue. LTX-315 potentially represent a better non-surgical alternative for patients suffering from this type of skin cancer. Basal cell carcinoma is the most common cancer type, representing a large and growing commercial market.
Lytix is receiving regulatory milestone payment, and if Verrica succeed to get the market approval for LTX-315 in BCC, this will generate both sales milestone payments and royalty payments from net sale of LTX-315. Our next-generation molecule, LTX-401, is a small molecule that has been developed for deep-seated cancer, including liver cancer. LTX-401 may be used as a monotherapy, but also has demonstrated strong, strong synergy with checkpoint inhibitors. It's a phase I ready asset and represent a large market potential within different types of deep-seated cancer.
To sum up this webinar, we have today reported that LTX-315, in combination with pembrolizumab, demonstrate encouraging preliminary results in heavily pretreated melanoma patients that have previously failed on anti-PD-1, PD-L1 treatment. with one partial response and a disease control rate of 43% so far. This is still at an early stage of the study, and first data set from all 20 patients will be presented early 2024. We are in the process of submitting an amendment to get an approval to start the expansion cohort with up to 20 additional patients.
We plan to start an advanced study in early-stage melanoma patient with LTX-315 and pembrolizumab early 2024. Promising early results have been reported for Verrica phase II study in basal cell carcinoma, and we look forward to see the final results from this study in 2024. Our molecules can be developed for several different cancer indication, both as a mono or combination therapy. Due to their unique way of working, we are also seeing- we also see commercial avenues for additional molecules in our pipeline. With this summary, I will hand over to our Head of Investor Relations, Ole Peter Nordby, who will lead the Q&A session.
Yes, we are now ready for the Q&A session, and as Øystein mentioned, you can submit your question by following the instructions on the webcast application. And I should inform you that during this session, we would like to concentrate on the questions regarding what has been presented at the poster at ESMO, through the press release and the presentation, delivered here in the studio by Øystein and Graeme. For the sake of the time, we will answer the questions regarding other matters, first, at the time of the Q3 report, which will be delivered in three or four weeks' time.
So we are now ready for the first questions. And this one comes in Norwegian, so I'll translate it. If patients failed on Nivolumab prior to the trial, is there any chance they could respond to pembro without LTX-315? What has been seen historically. That one is for you, Graeme.
Yeah. Thanks, Ole Peter. So, there's always a possibility that patients could respond on re-challenge, but data sets that have been presented on that show a generally low level of response, less than or equal to 10%. As you can see from the data in this trial, our patients who show shrinkage of lesions beyond that one patient, so... Okay, thank you.
Thank you. The next one, are you satisfied this is the injection dosing and schedule to proceed with, or could the dose per injection or schedule be changed in the expansion cohort?
From a clinical trial design point of view, we will continue with this injection and dosing schedule. Of course, we'll always evaluate our data closely and look at things, but we don't believe that changing dosing in the middle of a trial would be a reliable thing to do. If we were going to explore dosing changes, we would probably do it in a separate protocol, but we do believe that the dosing schedule that we're following here is appropriate and well-tolerated.
Thank you. Then it's a question regarding the evaluation criteria. Is there a better way to document efficacy other than RECIST 1.1? You have good injected lesions responses that aren't counted in the ORR. Does this not understate the efficacy?
Well, that is a good question. So RECIST 1.1 is how we've traditionally followed cancer studies, and that was originally based when we were using chemotherapy and systemic therapies. There is, of course, iRECIST, which does further help. And originally in this study, we were looking at lesions using a thing called it RECIST. We have looked at that fairly closely, but actually, that is quite challenging to implement in practice. So we will continue to look at ways to fully evaluate the efficacy of our treatment, but RECIST 1.1 is the standard, and that's the reason we're following that in this particular trial.
Thank you. And then the question goes, are these last-line patients, what would the patient's standard treatment have been if they were not in this trial?
Unfortunately, as I mentioned in the presentation, there are few treatment options for these, these patients. So essentially, these patients only have trial therapies to be considered. They've passed all standard of care, so limited treatment options, and that's why they would be looking to be enrolled in a trial like ours.
And a question for clarification only: do you include injected lesions in the target lesions? That is, is the response rate based on injected as well as non-injected lesions? We might have touched upon this previous, but we-
We, we-
-could answer.
We did touch on this. So, response is based on RECIST lesions, and RECIST lesions are not included in the evaluation of response. We did report on our case studies of what happened in the injected lesions, but RECIST is driven by target lesions, and injected lesions in our study were not defined as target.
Question or two regarding the case that were presented. Did the patient with a 90% response rate only have one target lesion? It's a more detailed question.
No, I think, as I presented, there was a number of target lesions for that, that patient. There was one main target lesion. The minimum was one target lesion, but the patient had multiple target lesions.
We are approaching the end of the questions here. But we should add this one. Of the cases of stable disease, did any receive Pembro in prior rounds?
Yes, all the patients had to have failed the checkpoint inhibitor. So some of those patients had definitely received Pembro, as a prior treatment line and had been documented as failing that treatment.
Then a last question regarding what will happen in the future, and it goes like this: How unusual is it for melanoma patients to convert from stable disease into partial response? Is it possible to answer that, Graeme?
It's not directly possible, but we certainly have seen lesions shrink later on this trial than is traditionally seen with a checkpoint inhibitor alone. There's definitely lesions in this trial that are still trending down, so we will continue to evaluate the data and monitor these patients closely.
And then, I have to ask for excuse, a last question popped up here. What is the reason that injected lesions can't be target lesions under RECIST 1.1?
They could be considered as resistant lesions. We have followed a stricter definition, because essentially, if you put a needle into a lesion, you're sometimes impacting the size of that lesion. So, that's the approach that we followed in this particular trial.
Yes, and that ends the Q&A session for today. Thank you.