William Marshall
Analyst · Evercore
Thanks, Dan. Good afternoon, everyone, and thank you for joining us for our corporate update call for the fourth quarter and full year 2018. We will begin today's call with an update on our clinical programs and a brief review of our financials before opening up the call for questions.
Looking back over 2018, we are excited by the ongoing advancements made across our development pipeline, which includes 3 clinical stage microRNA-targeted product candidates for patients across several indications with high unmet medical need. We believe the data we have reported to date on these product candidates has been compelling and supports the continued development of the product candidates for these disease indications.
During 2018, we presented top line data from our Phase I trial of cobomarsen that demonstrated durable responses in patients with mycosis fungoides, the most common form of cutaneous T-cell lymphoma, or CTCL, as measured by an improvement in total skin tumor burden scoring and quality of life. In addition, cobomarsen appeared to be generally well tolerated at all dose levels evaluated and for extended periods of time -- of treatment. This past January at the Annual T-cell Lymphoma Forum, we presented complete Phase I CTCL data and interim adult T-cell leukemia/lymphoma or ATLL data from this trial.
In regards to CTCL, based on the modified severity-weighted assessment tool or mSWAT score, which is a measurement of the severity of skin disease over a patient's entire body, 33 of 36 patients or 92% showed improvements. These improvements in mSWAT scores were observed as early as 17 days after a patient's first dose, with the greatest improvement in mSWAT scores seen after 1 or more months of dosing. Additionally, 5 of 8 patients receiving 300 milligram IV infusion achieved a 50% or greater mSWAT score reduction, which is a partial response. Of those 5 patients, 4 maintained the partial response for at least 4 consecutive months. The ability to maintain the partial response for at least 4 months is also known as ORR4 and is the primary endpoint that we will measure in the SOLAR Phase II clinical trial of cobomarsen.
We believe that the Phase I data for cobomarsen in treating MF patients achieved clinical proof-of-concept, which supported our decision to advance cobomarsen into the SOLAR trial. As a reminder, 300 milligram IV infusion is the dose and route of administration being used in the SOLAR Phase II clinical trial. In terms of the status of the SOLAR trial, we are focused on onboarding up to 60 sites worldwide, including those we believe will be high-enrolling sites. We expect initial dosing to begin early in 2019. While the on-boarding process for our initial clinical sites has been longer than we had originally anticipated, we ultimately believe that enrollment of patients in 2019 will be positively impacted by the site selection and patient outreach efforts of our team.
I'm pleased to say that due to the ongoing efforts of our team to communicate with the sites and move ahead with direct physician and patient outreach, we believe the SOLAR trial remains on track to deliver top line data within our originally guided time frame of the second half of 2020.
As a quick overview, our SOLAR trial is designed to evaluate the safety and efficacy of cobomarsen in an active control comparison trial versus vorinostat in patients with CTCL. The trial is expected to enroll approximately 65 patients per treatment group. The primary endpoint of the SOLAR trial is the rate of objective response defined as 50% or greater improvement in the severity of a patient's skin disease over the entire body with no evidence of disease progression in the blood, lymph nodes or viscera maintained for at least 4 consecutive months. Progression-free survival will be a secondary endpoint, and we plan to use patient-reported outcomes as additional secondary endpoints to monitor quality-of-life improvements. Based on our discussions with the FDA, we expect that achievement of the primary endpoint from the SOLAR trial could allow us to apply for accelerated approval for cobomarsen in CTCL in the United States.
As previously disclosed, we are pleased to be conducting the SOLAR trial in association with the Leukemia and Lymphoma Society, which is providing invaluable support, including up to $5 million in funding upon the achievement of specified milestones in connection with the trial.
As I mentioned earlier, we also presented new data on cobomarsen in patients with ATLL at the Annual T-cell Lymphoma Forum in January. As of December 13, 2018, a total of 8 ATLL patients had been treated with cobomarsen in the expanded Phase I clinical trial. Of these 8 patients, 5 patients with acute and lymphomatous ATLL that were in partial remission had remained stable or improved while on cobomarsen monotherapy from 3 to 13 months, and we're still continuing with treatment as of the December 13, 2018, cutoff date.
In addition to no evidence of disease progression, we have demonstrated a decrease in biomarkers on the circulating tumor cells indicative of disease severity, including Ki67, a marker of cell proliferation. Elevations of Ki67 have been shown to correlate with poor life expectancy for ATLL patients.
In regard to the safety while on cobomarsen monotherapy, there have been no serious adverse events, or SAEs, reported in patients related to study drug and none of the patients demonstrated evidence of opportunistic infections, which are common in patients with this disease. The patients in this trial had previously failed on other therapies and the median survival for patients with acute disease typically ranges from 4 to 10 months after diagnosis. We believe it is important to remember that the ATLL subsets seen in these initial patients are associated with extremely poor prognosis despite existing treatments, and new therapies are essential to improve patient outcomes in this devastating disease.
Turning to diffuse large B-cell lymphoma or DLBCL, which is the most common type of Non-Hodgkin lymphoma accounting for up to 1/3 of patients with newly diagnosed Non-Hodgkin's lymphoma in the United States. Included in our presentation of data from the Phase I cobomarsen trial in January, we presented data on 3 patients diagnosed with the activated B-cell subtype of DLBCL and treated with cobomarsen. As of January 8, 2019, 1 patient had seen a complete reduction in 1 of 2 measured lymph nodes and stabilization in a second lymph node after 7 weeks of therapy. This patient remains on cobomarsen. The other 2 patients discontinued therapy after less than 1 month due to lack of immediate response. Previously, all 3 patients had relapsed after multiple cycles of treatments with other therapies received over 12 to 56 months from diagnosis. Prior treatments for these patients range from standard of care to experimental chemotherapy. While this was a small sample size, we are pleased with the activity reported in the responding patient. We will continue to evaluate cobomarsen in DLBCL and chronic lymphocytic leukemia patients as we believe it has the potential to improve the quality of life for these patients.
Turning to remlarsen. We are currently conducting a double-blinded randomized Phase II clinical trial for remlarsen that is expected to report data in the second half of 2019. This Phase II trial is assessing the safety, tolerability and activity of remlarsen in the prevention or reduction of keloid formation in subjects with a history of keloid scars, a persistent form of hypertrophic scarring. We expect the trial will initially enroll up to a 12-subject cohort consisting of individuals that are predisposed to keloid formation after trauma.
In this trial, subjects receive small matching excisional wounds that are sutured and then injected with either remlarsen or placebo. Thus, patients are serving as their own control, which increases the statistical power of the clinical trial with a relatively small number of patients. The lesions will be observed for up to 12 months to determine presence or absence of keloid formation. We believe this is an exciting opportunity to build on the Phase I data in induced cutaneous fibrosis where remlarsen appeared to reduce scar tissue deposition in human -- healthy human volunteers without affecting wound healing.
Turning to MRG-110. We are developing MRG-110 in collaboration with Servier. MRG-110 is an inhibitor of microRNA-92, which has been shown to be important in the regulation of new blood vessel growth and healing. As a reminder, MRG-110 is being evaluated in 2 separate Phase I trials intended to support additional clinical trials that could allow for its potential use in the treatment of multiple indications, including heart failure and other conditions where patients would benefit from increased new blood vessel growth and better oxygenation, including burns and difficult-to-heal lacerations. We expect to announce data from these trials in 2019.
We have made steady progress in advancing our 3 clinical stage programs and entered 2019 with several near-term clinical milestones. We believe the data that has been presented recently supports the current strategy for our 3 clinical stage microRNA-based product candidates. We believe that our ongoing and planned clinical trials for these candidates will provide further evidence supporting the potential of microRNA-based therapeutics to become an important new class of targeted therapies for patients in need.
With that, I will now turn the call over to Jason Leverone, our Chief Financial Officer, to review the financial results we have reported earlier today. Jason?