Aulos Bioscience Reports Positive Phase 2 Results for Imneskibart-Based Regimens in Checkpoint Inhibitor-Refractory Melanoma and NSCLC at SITC 2026
Aulos Bioscience, an immuno-oncology company focused on developing innovative immune-activating antibody therapies for cancer, has announced positive Phase 2 clinical findings for its lead investigational candidate, imneskibart (AU-007), in heavily pretreated patients with doublet checkpoint inhibitor (CPI)-refractory melanoma and checkpoint inhibitor-refractory adenocarcinoma non-small cell lung cancer (NSCLC). The latest findings demonstrate encouraging antitumor activity, durable clinical responses, and favorable progression-free survival outcomes in two challenging cancer populations with limited remaining treatment options.
The results were presented in two posters at the Society for Immunotherapy of Cancer (SITC) 2026 Annual Meeting in Phoenix, Arizona. The clinical findings support the continued development of imneskibart-based treatment combinations and provide additional evidence of the investigational therapy’s potential to address treatment resistance in advanced solid tumors.
Imneskibart was evaluated in combination with low-dose, subcutaneous aldesleukin, with or without additional checkpoint inhibitors, in patients whose cancers had progressed despite previous immunotherapy treatments. The melanoma study evaluated both a doublet regimen consisting of imneskibart and low-dose aldesleukin and a triplet regimen that added nivolumab. In patients with advanced adenocarcinoma NSCLC, investigators evaluated imneskibart combined with low-dose aldesleukin and avelumab.
The melanoma findings showed that the triplet combination achieved a median progression-free survival (PFS) of 9.1 months and an objective response rate (ORR) of 28% among 18 response-evaluable patients. This included one confirmed complete response and four partial responses. The doublet regimen demonstrated a median PFS of 6.9 months and an ORR of 29% among 14 response-evaluable patients, including a confirmed complete response that remained durable for more than 32 months.
In the NSCLC cohort, the combination of imneskibart, low-dose subcutaneous aldesleukin, and avelumab achieved a median PFS of 5.8 months, a confirmed ORR of 21%, and a disease control rate (DCR) of 86%. Median overall survival (OS) had not been reached at the time of analysis, with a median follow-up of 10.6 months.
These findings are particularly encouraging because patients enrolled in the studies had received multiple previous treatment regimens and had experienced disease progression despite checkpoint inhibitor-based therapies.
Aron Knickerbocker, President and Chief Executive Officer of Aulos Bioscience, highlighted the importance of the clinical findings and the potential of imneskibart in difficult-to-treat cancer populations.
According to Knickerbocker, the results represent encouraging progress in two challenging oncology indications: melanoma and NSCLC that have progressed following multiple previous treatments. He emphasized that the observed deep and durable tumor responses, consistent pharmacodynamic activity, and manageable safety profiles provide a strong foundation for advancing imneskibart into randomized clinical trials.
He also noted that the findings reinforce the company’s confidence in the differentiated mechanism of imneskibart and its potential to become an important treatment option for patients with advanced melanoma and lung cancer.
Phase 2 Clinical Data Demonstrate Encouraging Activity in Heavily Pretreated Melanoma
The melanoma findings provide evidence of clinical activity for imneskibart-based regimens in patients whose disease progressed following previous doublet checkpoint inhibitor therapy.
The clinical evaluation included patients treated with two different regimens: imneskibart combined with low-dose, subcutaneous aldesleukin, and imneskibart combined with low-dose, subcutaneous aldesleukin and nivolumab.
Both treatment approaches demonstrated encouraging clinical outcomes, including objective tumor responses and prolonged progression-free survival.
The triplet combination was evaluated in patients who had received a mean of 2.7 previous lines of treatment. Among 18 response-evaluable patients, the regimen achieved an ORR of 28%, including one confirmed complete response and four partial responses.
The magnitude of tumor reduction among patients achieving partial responses was also notable. The four partial responses corresponded to tumor reductions of 81%, 74%, 65%, and 40%, respectively.
The median PFS for patients receiving the triplet regimen was 9.1 months, indicating encouraging disease control in this heavily pretreated population.
The baseline disease characteristics further highlight the significance of the findings. All but four patients had liver and/or lung metastases at study entry, including all patients who achieved partial responses.
Median overall survival data for the triplet cohort remained immature at the September 18, 2026, data cutoff. At that time, 16 of 20 patients were alive or censored, with a median follow-up of 5.6 months.
These findings provide preliminary evidence that combining imneskibart with low-dose aldesleukin and nivolumab may generate meaningful antitumor activity in patients with melanoma that has become resistant to previous checkpoint inhibitor combinations.
Imneskibart Doublet Regimen Shows Durable Responses in CPI-Refractory Melanoma
The doublet regimen of imneskibart and low-dose, subcutaneous aldesleukin also demonstrated encouraging clinical activity in patients with advanced melanoma.
Among 14 response-evaluable patients, the combination achieved an ORR of 29%, with a median PFS of 6.9 months. Patients in this cohort had received a mean of 2.4 previous lines of therapy before entering the study.
One of the most notable observations was the durability of tumor responses among several patients receiving the doublet combination.
A confirmed complete response demonstrated a 100% reduction in measurable target tumor burden and remained durable for more than 32 months. The patient continued to be followed after completing treatment.
Additional patients demonstrated substantial tumor reductions and prolonged treatment duration.
One patient experienced a 48% reduction in target tumor size and remained on the study for 13 months. Another achieved a 47% tumor reduction and continued treatment for more than 14 months at the time of reporting.
A separate patient with measurable non-target tumors experienced a 58% reduction in tumor size and remained on the study for approximately 18.5 months.
These findings indicate that some patients experienced prolonged clinical benefit following treatment with imneskibart and low-dose aldesleukin, despite having previously received multiple therapies.
Furthermore, nine of the 14 patients achieved stable disease, demonstrating that the treatment combination was associated with disease control across a broader group of participants beyond those achieving objective tumor responses.
Median overall survival in the doublet cohort was 16.1 months at a median follow-up of 18 months.
The durability of the complete response and the prolonged treatment durations observed in several patients provide additional support for continued evaluation of the doublet regimen.
Progression-Free Survival Compares Favorably with Historical Melanoma Treatment Benchmarks
The clinical findings from the melanoma cohorts are particularly relevant when considered alongside previously reported outcomes from salvage-treatment studies involving patients with anti-PD-1-refractory melanoma.
Patients whose melanoma progresses following checkpoint inhibitor treatment frequently require alternative therapeutic strategies. However, available treatment options in this setting may provide limited and relatively short periods of disease control.
Published results from the Phase 2 LEAP-004 study evaluating lenvatinib combined with pembrolizumab reported a median PFS of 4.2 months in patients with anti-PD-1-refractory melanoma.
Similarly, the RELATIVITY-020 study evaluating nivolumab combined with relatlimab reported median PFS outcomes ranging from 2.1 to 3.2 months across the relevant patient populations.
Additional context is provided by a 2026 multicenter retrospective study conducted by the Dermatologic Cooperative Oncology Group (DeCOG). The study evaluated 120 heavily pretreated patients with advanced melanoma who received anti-PD-1 therapy combined with lenvatinib.
The retrospective analysis reported a median PFS of 3.5 months. Notably, 98% of patients had previously received the combination of ipilimumab and nivolumab.
Against this historical background, the median PFS outcomes of 9.1 months with the imneskibart triplet regimen and 6.9 months with the doublet regimen are encouraging.
These comparisons suggest that imneskibart-based combinations may offer a potential treatment approach for patients with melanoma that has progressed following previous checkpoint inhibitor therapy.
However, the results are based on separate clinical studies with different patient populations, study designs, and treatment histories. Therefore, the cross-trial comparisons are descriptive and do not establish that imneskibart combinations are superior to other available therapies.
Further randomized clinical studies will be important to determine the relative clinical benefit of the investigational regimens.
Imneskibart Triplet Demonstrates Clinical Activity in CPI-Refractory Adenocarcinoma NSCLC
In addition to melanoma, Aulos Bioscience reported positive Phase 2 findings from its evaluation of imneskibart in patients with advanced adenocarcinoma NSCLC whose disease had progressed following checkpoint inhibitor treatment.
The NSCLC cohort evaluated the combination of imneskibart, low-dose subcutaneous aldesleukin, and avelumab, an anti-programmed death-ligand 1 (PD-L1) antibody.
Among 14 response-evaluable patients with adenocarcinoma NSCLC, the triplet regimen achieved a median PFS of 5.8 months and a confirmed ORR of 21%.
Three patients demonstrated measurable target tumor reductions of 42%, 43%, and 45%, respectively.
The durability of these responses was also encouraging. One patient remained on the study for eight months following a 42% tumor reduction. Another patient experienced a 43% reduction and continued treatment for more than 12 months at the time of reporting. A third patient achieved a 45% tumor reduction and remained on the study for six months.
In addition to the objective responses, nine of the 14 patients achieved stable disease.
This resulted in a disease control rate of 86%, indicating that the treatment combination was associated with either tumor shrinkage or disease stabilization in most response-evaluable patients.
The patients in the adenocarcinoma NSCLC cohort had received a mean of 2.6 previous lines of treatment, demonstrating the substantial treatment exposure and advanced disease characteristics of the enrolled population.
Median overall survival had not been reached at the time of the analysis, with a median follow-up of 10.6 months.
These findings provide additional evidence of the potential activity of imneskibart-based immunotherapy across different CPI-refractory solid tumor types.
NSCLC Results Compare Favorably with Historical Docetaxel Outcomes
The median PFS of 5.8 months observed with the imneskibart triplet regimen provides an encouraging comparison with historical chemotherapy outcomes in advanced nonsquamous NSCLC.
In the randomized Phase 3 TROPION-Lung01 trial, the docetaxel treatment arm demonstrated a median PFS of 3.6 months in the nonsquamous NSCLC subgroup.
Patients in the overall TROPION-Lung01 docetaxel arm had received an estimated mean of at least 1.5 previous lines of therapy, compared with a mean of 2.6 previous lines among patients enrolled in the Aulos adenocarcinoma NSCLC cohort.
This difference in prior treatment exposure is important when interpreting the clinical findings because the Aulos cohort included patients who had undergone multiple previous treatment regimens and experienced disease progression despite checkpoint inhibitor therapy.
The 5.8-month median PFS observed with imneskibart, aldesleukin, and avelumab therefore provides an encouraging early signal in this difficult-to-treat population.
Nevertheless, the comparison involves different studies and patient populations and should not be interpreted as evidence of comparative superiority. Randomized clinical trials will be required to establish the treatment’s efficacy and determine its potential position within the NSCLC treatment landscape.
Pharmacodynamic Findings Support Imneskibart’s Differentiated Mechanism of Action
Beyond the clinical efficacy findings, Aulos Bioscience reported pharmacodynamic results that provide additional support for the biological activity of imneskibart.
The company’s clinical development strategy focuses on redirecting interleukin-2 (IL-2) activity toward immune effector cells while reducing stimulation of regulatory T cells (Tregs), which can suppress antitumor immune responses.
IL-2 is an important immune-signaling molecule involved in the growth, activation, and function of several immune-cell populations. However, its biological activity can also support regulatory T cells, which play a role in limiting immune activation.
In cancer, increased Treg activity within the tumor microenvironment can contribute to immunosuppression and weaken the immune system’s ability to eliminate malignant cells.
Imneskibart is designed to influence this balance by promoting immune effector activity and reducing the immunosuppressive effects associated with Tregs.
The pharmacodynamic findings from the melanoma cohorts demonstrated sustained reductions in regulatory T cells following treatment.
Investigators also observed increases in the CD8/Treg ratio, an important measure of the balance between antitumor immune effector cells and immunosuppressive regulatory cells.
Patients who experienced Treg reductions greater than the median reduction of 56% demonstrated longer time to progression compared with patients who experienced smaller reductions.
Across both the melanoma doublet and triplet treatment groups, increases in CD8-positive T cells and CD8/Treg ratios were accompanied by corresponding decreases in Treg levels.
These findings support the company’s proposed mechanism of redirecting IL-2 activity toward immune effector cells while limiting stimulation of immunosuppressive T-cell populations.
The results also provide a potential biological explanation for the observed tumor responses and prolonged disease control in some patients.
Increased NK Cell Activity Observed in NSCLC Patients
The pharmacodynamic analysis in the NSCLC cohort demonstrated additional changes in immune-cell populations following treatment.
Investigators observed increases in CD8/Treg ratios and natural killer (NK) cells compared with baseline measurements.
Importantly, greater increases in these immune-cell populations were associated with longer progression-free survival.
The increase in NK cells may be particularly relevant to the combination of imneskibart with avelumab.
Avelumab is an anti-PD-L1 monoclonal antibody that contains an active Fc domain and can mediate antibody-dependent cellular cytotoxicity (ADCC).
ADCC is an immune-mediated mechanism through which antibody-coated target cells are recognized and destroyed by immune cells, including natural killer cells.
By increasing NK-cell populations, imneskibart may potentially complement the ADCC activity associated with avelumab.
On average, treatment with imneskibart increased NK-cell counts by nearly three-fold compared with baseline levels.
This observation suggests that the combination may support multiple immune mechanisms, including checkpoint inhibition, enhanced immune effector activity, and antibody-mediated cancer-cell destruction.
The pharmacodynamic findings provide additional scientific support for investigating imneskibart in combination with different immunotherapy agents across multiple tumor types.
Imneskibart-Based Regimens Demonstrate Manageable Safety Profiles
Aulos Bioscience also reported encouraging safety findings across the melanoma and NSCLC clinical cohorts.
Most drug-related adverse events associated with imneskibart and low-dose subcutaneous aldesleukin were Grade 1 or Grade 2 in severity.
The safety profile was generally manageable when imneskibart was administered alone with aldesleukin or as part of combination regimens containing nivolumab or avelumab.
Importantly, investigators reported no cases of capillary leak syndrome and no treatment-related deaths.
Capillary leak syndrome is a potentially serious complication associated with certain immune-modulating therapies, particularly some IL-2-based treatment approaches. The absence of reported cases is an encouraging observation in the current clinical evaluation.
The emerging safety profile of the doublet and triplet regimens was consistent with the known safety characteristics of nivolumab and avelumab when administered with imneskibart and aldesleukin.
Additionally, investigators did not identify new toxicity signals in the reported findings.
These results suggest that the treatment combinations may offer a manageable safety profile while producing pharmacodynamic changes and antitumor activity.
Further evaluation in larger patient populations will be necessary to better characterize the incidence, severity, and long-term management of potential adverse events.
Clinical Data Cutoff and Patient Population
The clinical findings presented at SITC 2026 were based on data available as of September 18, 2026.
Across the melanoma Phase 1 and Phase 2 cohorts, data were available from 51 patients treated with imneskibart-based regimens, with and without nivolumab.
Among these patients, 14 were evaluable for response in the imneskibart doublet cohort, while 18 were evaluable for response in the triplet cohort.
For the NSCLC program, data were available from 26 patients with either adenocarcinoma or squamous histology who received the Phase 2 avelumab combination.
Of these 26 patients, 16 had adenocarcinoma histology, and 14 were evaluable for response.
The findings provide an early clinical assessment of imneskibart across two cancer indications characterized by substantial unmet medical needs, particularly among patients who have progressed following previous checkpoint inhibitor-based treatments.
Aulos Bioscience Advances Development of Imneskibart
The positive Phase 2 findings represent an important milestone for Aulos Bioscience as the company continues advancing imneskibart as a potential next-generation immunotherapy.
The melanoma results demonstrated median PFS of 9.1 months with the triplet regimen and 6.9 months with the doublet regimen, alongside objective responses and evidence of prolonged tumor control.
In adenocarcinoma NSCLC, the combination of imneskibart, aldesleukin, and avelumab achieved median PFS of 5.8 months, an ORR of 21%, and a disease control rate of 86%.
The pharmacodynamic findings further support the investigational therapy’s differentiated biological approach, with reductions in regulatory T cells, increases in CD8/Treg ratios, and enhanced NK-cell activity.
The manageable safety profile, absence of capillary leak syndrome, and lack of treatment-related deaths also provide encouraging information for continued clinical development.
According to the company, these findings establish a compelling foundation for advancing imneskibart into randomized clinical trials.
Aulos Bioscience aims to further evaluate the treatment’s potential to overcome immune resistance and improve outcomes in patients with advanced melanoma and NSCLC who have limited therapeutic alternatives.
As clinical development progresses, additional studies will be important to confirm the durability of responses, establish the optimal treatment combinations, and determine whether imneskibart can provide meaningful benefits compared with existing treatment approaches.
Through its immuno-oncology research program, Aulos Bioscience is working to develop differentiated immune-activating therapies that could expand treatment possibilities for patients with difficult-to-treat cancers.
About Imneskibart
Imneskibart (AU-007) is a human IgG1 monoclonal antibody designed by leveraging artificial intelligence that is highly selective to the CD25-binding portion of IL-2. With a mechanism of action unlike any other IL-2 therapeutic in development, imneskibart redirects IL-2 to reinforce anti-tumor immune effects.
This is achieved by preventing IL-2, either exogenous or secreted by effector T cells, from binding to trimeric receptors on regulatory T cells while still allowing IL-2 to bind and expand effector T cells and NK cells. This prevents the negative feedback loop caused by other IL-2-based treatments and biases the immune system toward activation over suppression. Imneskibart also prevents IL-2 from binding to CD25-containing receptors on eosinophils, as well as vasculature and pulmonary endothelium, which may significantly reduce the vascular leak syndrome and pulmonary edema associated with high-dose IL-2 therapy.
About Aulos
Aulos Bioscience is an immuno-oncology company working to revolutionize cancer patient care through immune-activating antibody therapeutics that direct patients’ immune systems toward killing tumor cells. Matching world-class machine learning from co-founder Biolojic Design with an in-depth understanding of the immune system, Aulos’ initial clinical candidate, imneskibart (AU-007), is a human antibody designed by leveraging artificial intelligence that harnesses the power of IL-2 to induce tumor killing while limiting the immunosuppression and toxicities typically associated with this validated pathway. The company was founded by Biolojic Design and Apple Tree Partners (ATP) and is led by pioneers in the fields of artificial intelligence, antibody development and cancer immunotherapies.