Jonathan Zalevsky
Analyst · Oppenheimer
Thank you, Howard. Beginning with REZPEG, this program is the most advanced IL-2 T reg mechanism in the field. In the setting of atopic dermatitis, there are 3 important issues that patients with this disease continue to face. First, there is a need for more efficacy, a greater magnitude of response and rapid onset of treatment.
For example, only about half of patients treated with IL-13 based biologics achieved a meaningful clinical benefit. Second, patients lack durable responses and therapy free remission. Once current therapies are discontinued, patients rebound rapidly. And third, treatments with tolerable long-term safety profiles are lacking. This is especially important given the chronic nature of the disease and the need for continuous dosing.
We believe there are major opportunities in this disease state that REZPEG could potentially address. In our Phase Ib data in atopic dermatitis, REZPEG demonstrated dose-dependent efficacy and encouraging durability seemed long after the patients completed the 12-week induction period. In fact, for both patient-reported outcomes and physician-assessed endpoint, we observed the same trend, rapid onset of effect, dose-dependence and long durability of control.
Additionally, REZPEG was well tolerated and treatment with REZPEG did not induce antidrug antibodies in patients, which has been reported with some examples in the IL-2 mutein class. We are looking forward to publishing in a peer review journal this year, new translational biomarker data from the study, along with the clinical and safety data from atopic dermatitis and psoriasis.
The rapid onset of action and the type of extended disease control after the end of dosing, rivals are outperformed that of Dupilumab or JAK inhibitors. These promising data have us and KOLs very enthusiastic about the potential for long-lasting responses and infrequent maintenance dosing with REZPEG and atopic dermatitis.
Enrollment is progressing on track in our Phase IIb study of REZPEG in biologic-naive atopic dermatitis patients. Our goal is to enroll roughly 400 patients with 3 different regimens of REZPEG versus placebo evaluated over a 16-week induction period. After the induction period, patients that meet a threshold to advance from induction to maintenance will be rerandomized into 1 of 2 maintenance regimens at different dosages at either once a month or once every 3-month dosing schedules.
We expect initial data in the first half of 2025. And moving to alopecia areata, we believe REZPEG has strong scientific rationale in this indication. Alopecia areata is also a disease of the skin, where your immune system starts to attack the hair follicle, weakening the ability of stem cells to grow hair. With prolonged immune attack, it causes the hair follicle to release the hair altogether, resulting in baldness. And Biologically speaking, REZPEG, through its central pathway of T reg rescue is uniquely poised to address the diversity of immunopathology, providing broad potential for targeting multiple dermal diseases, including alopecia areata. And specifically, alopecia areata is a breakdown of immune privilege in the hair follicle. And so what does this mean exactly?
Well, normal hair follicles exist in the state of immune privilege, so in other words, there are no immune cells, no MHC expression and basically no immune system components inside the follicle. We know this exclusion of the immune system is needed to maintain healthy, long-lived and continuously functioning stem cells to grow hair during our lifespan. In people with alopecia areata, there is a breakdown of the immune privilege in the hair follicle, infiltration of the immune system, inflammation and all this leads to hair loss and eventually complete baldness.
Preclinical studies in vitro and in mice implanted with human alopecia skin samples have shown that T regs are essential for restoring and maintaining immune privilege and thus are a novel therapeutic strategy for the treatment of this disease. And consequently, we believe the T reg mechanism of REZPEG can restore immune privilege and could provide durable disease control, which would be game-changing in this indication. And alopecia areata JAK inhibitors are the only agents approved in this field, and it is a lifelong treatment.
With JAK inhibitors, it could take a patient anywhere from 6 to 12 months to grow hair and once a patient stops taking a JAK inhibitor, which may happen for a variety of reasons such as toxicity, their hair falls out again rapidly. And there is a high unmet need in this patient population for tolerable treatment options that provide durable responses. And for these reasons, we believe there is an opportunity for REZPEG to become a novel biologic therapy in alopecia areata.
We are well underway with enrolling patients into the Phase IIb study of REZPEG in alopecia areata. This study plans to recruit roughly 80 patients with severe to very severe disease that will be randomized to REZPEG or placebo. Patients will be treated for a period of 36 weeks and observed up to 60 weeks in total. Our primary endpoint for this study is mean percent improvement in SALT for the severity of our alopecia tool at week 36.
We will also be looking at a number of other secondary endpoints, including proportion of patients that were observed to have varying degrees of improvement in SALT score. We expect to have top line data in the first half of 2025. Now turning to NKTR-0165, our TNFR2 agonist antibody. TNFR2 is highly expressed on T regs, myeloid suppressor cells, regulatory B cells, neuronal cells and others, and TNFR2 agonism has been shown to potentiate the effector functions, suppressive functions and maintenance of lineage stability of T regs, especially in non-lymphoid tissue compartments. If TNFR2 is absent the phenotypic effect is autoimmunity and other genetic conditions that resemble FoxP3 loss of function.
In contrast, its presence and activation of its signaling has been associated with immunoregulatory function and protective effects for multiple cell populations and tissues in the body. The TNFR2 agonist program is built upon many years of T reg experience that we've gained from studying REZPEG. TNFR2 is the most abundant TNF superfamily member expressed on T reg and the key driver of NFCP would be signaling in those cells, which is why we are very excited about this program and target.
In our program, we collaborated with an AI-based antibody engineering company to screen a wide diversity of TNFR2 selective binding antibody for novel modes of TNFR2 agonism. We are very excited with the unique and differentiated profile of the antibodies that we have discovered and we are rapidly advancing these into the clinic. We anticipate our IND submission for this program in the middle of next year. Examples of indications that could be addressed by TNFR2 agonism include multiple sclerosis, mucosal immunology conditions, such as ulcerative colitis in GI or other oral mucosal diseases and even dermal autoimmune diseases like Vitiligo. As Howard mentioned, data from our preclinical research of this program has been selected for poster presentation at EULAR.
This will be the first look at this novel therapeutically active anti-TNFR2 agonist antibody, and we're looking forward to presenting these data. There is growing interest for a novel selective TNFR2 agonists like NKTR-0165 and as we move forward with our IND-enabling study, we will continue to be open to the opportunity of working with companies that have interest in these areas to strategize on the best path forward.
And finally, turning to our IL-15-based oncology program, NKTR-255. We believe the IL-15-based mechanism of action has promising potential as the combination agent with cell therapies and other mechanisms such as checkpoint inhibitors. We are exploring the best partnering paths for continued development for this drug candidate. We are completing our NKTR sponsor trial, combining NKTR-255 with approved CD19 CAR-Ts, BREYANZI and Yescarta for treatment of patients with large B-cell lymphoma.
A separate investigator-sponsored trial with Fred Hutch is also evaluating the combination of NKTR-255 and BREYANZI, and we plan on presenting data from this ongoing study at a medical meeting later this year.
We continue to collaborate with AbelZeta, a leading cell therapy company to evaluate NKTR-255 in combination with their tumor-infiltrating lymphocytes or TILs, TIL therapy in an ongoing Phase I clinical trial in patients with advanced non-small cell lung cancer, who do not respond to anti-PD-1 therapy. Lastly, we are continuing to work with our partner, Merck KGaA in the Phase II JAVELIN bladder Medley study evaluating NKTR-255 in combination with BAVENCIO and expect to report interim data, including PFS later this year.
And with that, I will turn the call over to Jennifer for a review of our financial guidance. Jennifer?