Salubris Biotherapeutics Presents Updated Phase 1b/2 Data for 5T4-Targeted ADC JK06 in Advanced Solid Tumors at ESMO 2026
Salubris Biotherapeutics, Inc., a clinical-stage biotechnology company focused on discovering and developing novel complex biologic therapeutics, has announced updated clinical data from its ongoing Phase 1b/2 study of JK06, an investigational 5T4-targeted antibody-drug conjugate (ADC), in patients with unresectable locally advanced or metastatic solid tumors. The study includes patients with non-small cell lung cancer (NSCLC), breast cancer, cervical cancer, and other tumors expressing the 5T4 target.
The updated findings are being presented at the European Society for Medical Oncology (ESMO) Congress 2026, held October 23–27 in Madrid, Spain. The results provide additional information on the clinical activity, durability of response, and safety profile of JK06 in patients who have received multiple previous lines of cancer treatment.
According to SalubrisBio, the latest findings build on clinical results previously presented at the American Association for Cancer Research (AACR) and the American Society of Clinical Oncology (ASCO). The updated analysis indicates that JK06 has demonstrated antitumor activity across several cancer subtypes, with responses observed in heavily pretreated patients. The company also highlighted findings in second-line and later squamous NSCLC that support further clinical development of JK06 as a monotherapy.
The data include outcomes from patients treated within the target dose range of 3.7–5.2 mg/kg, covering several disease-specific cohorts. Across these groups, objective response rates reached 33% in hormone receptor-positive (HR+) breast cancer and cervical cancer, while disease control rates varied by tumor type. The reported safety findings also indicate that treatment-related adverse events were predominantly low grade and manageable.
JK06 Demonstrates Potential Across Multiple Cancer Types
Commenting on the updated results, Sam Murphy, Chief Executive Officer of Salubris Biotherapeutics, said the findings reinforce the potential of JK06 across different subtypes of NSCLC, breast cancer, and cervical cancer.
“We are excited to present these updated Phase 1b/2 results, which further underscore the potential benefit JK06 can offer patients across various subtypes of NSCLC, breast cancer, and cervical cancer. Building upon our previously presented results at AACR and ASCO, we have observed frequent and durable benefit with JK06 treatment among heavily pretreated patients. Data in monotherapy from second-line and later squamous NSCLC support JK06’s advancement to later-stage studies,” Murphy said.
He added that the safety and efficacy profile observed to date could support the investigation of JK06 in combination with immune-based and targeted therapies, potentially expanding its role into earlier treatment settings.
“Additionally, the safety and efficacy profile of JK06 unlocks the potential for combination with immune and targeted therapies in earlier-line settings. We look forward to continuing our Phase 1/2 study of JK06 and deepening our understanding of this treatment as both a monotherapy and combination therapy,” Murphy said.
The company plans to continue evaluating JK06 through its ongoing Phase 1/2 program, which includes monotherapy and combination therapy cohorts designed to assess its activity across selected tumor types.
Overview of the Phase 1b/2 Clinical Study
The ongoing Phase 1/2 study, registered under ClinicalTrials.gov identifier NCT06667960, is an open-label clinical trial evaluating JK06 in patients with unresectable locally advanced or metastatic cancers. The trial was designed to assess the investigational therapy’s safety, tolerability, and antitumor activity while identifying an appropriate dose range for further clinical development.
The dose-escalation stage of the study has been completed. The trial is currently enrolling patients into multiple tumor-specific monotherapy and combination expansion cohorts. These cohorts include NSCLC, breast cancer, cervical cancer, and a basket cohort comprising other tumors that express 5T4.
JK06 is administered intravenously once every three weeks (Q3W). Tumor responses are assessed according to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), a standardized framework used in clinical trials to evaluate changes in tumor size and determine whether a patient has achieved a complete response, partial response, stable disease, or progressive disease.
As of September 21, 2026, a total of 249 patients had received JK06 across the study. This population included 42 patients in the dose-escalation stage and 207 patients enrolled in expansion cohorts.
Of the 249 patients treated, 230 received JK06 within the target dose range of 3.7–5.2 mg/kg. This target-dose population included 109 patients with NSCLC and 68 patients with breast cancer. The updated efficacy analysis focuses on selected tumor-specific cohorts within this dose range.
The findings provide an overview of response rates, disease control, duration of response, progression-free survival, and overall survival across the evaluated cancer populations. However, the reported outcomes represent data from an ongoing early-phase study and will require further evaluation in larger clinical trials.
Efficacy Findings in NSCLC, Breast Cancer, and Cervical Cancer
The updated analysis evaluated JK06 activity across five patient cohorts: squamous NSCLC, nonsquamous NSCLC without genomic alterations, EGFR-mutant NSCLC, HR+ breast cancer, and cervical cancer.
The median number of previous lines of therapy varied considerably among the cohorts, reflecting differences in treatment history and disease characteristics. Patients in the squamous and nonsquamous NSCLC cohorts had received a median of two previous lines of therapy. The EGFR-mutant NSCLC and cervical cancer cohorts also had a median of two prior lines, while patients with HR+ breast cancer had received a median of five previous lines of treatment.
The objective response rate (ORR), which measures the proportion of patients who experience a complete or partial tumor response, was 22% in squamous NSCLC and 22% in nonsquamous NSCLC without genomic alterations. In the EGFR-mutant NSCLC cohort, the ORR was 19%.
Among patients with HR+ breast cancer, the ORR reached 33%. The cervical cancer cohort also demonstrated an ORR of 33%. These findings indicate that tumor responses were observed across multiple cancer types, including populations with substantial previous treatment exposure.
Disease control rate (DCR), which includes complete responses, partial responses, and stable disease, also varied across the evaluated groups. The highest reported DCR was 84% in squamous NSCLC. The corresponding rates were 61% in nonsquamous NSCLC without genomic alterations, 57% in EGFR-mutant NSCLC, 59% in HR+ breast cancer, and 72% in cervical cancer.
The results suggest that JK06 may have activity beyond tumor shrinkage alone, with a proportion of patients experiencing disease stabilization during treatment. Nevertheless, the clinical significance of these outcomes will depend on additional follow-up and confirmation in subsequent studies.
Duration of response and progression-free survival
The updated data also included duration of response (DoR), which measures how long a patient’s tumor response is maintained, and progression-free survival (PFS), which measures the time patients remain alive without disease progression.
In the squamous NSCLC cohort, the median duration of response was 22.6 weeks, with a 95% confidence interval (CI) of 18.3 weeks to not estimable (NE). Median PFS was 22.1 weeks (95% CI: 17.3–31.4).
For nonsquamous NSCLC without genomic alterations, the median duration of response was 16.4 weeks (95% CI: 9.0–NE), while median PFS was 15.0 weeks (95% CI: 9.1–19.1).
In the EGFR-mutant NSCLC cohort, the median duration of response was 18.3 weeks (95% CI: 18.3–NE), and median PFS was 17.4 weeks (95% CI: 7.1–30.4).
Among patients with HR+ breast cancer, median duration of response had not been reached at the time of analysis, with a reported 95% CI of 9.1 weeks to NE. Median PFS was 18.1 weeks (95% CI: 8.6–NE).
In cervical cancer, median duration of response was also reported as NE. Median PFS was 17.7 weeks (95% CI: 9.7–NE).
A median value reported as not estimable means that the available data were insufficient to calculate that endpoint reliably at the time of analysis. It does not establish that responses will necessarily continue for a particular duration. Further follow-up will help clarify the durability of treatment benefit in these populations.
Overall survival findings
Overall survival (OS), which measures the time patients remain alive following the relevant study starting point, was another endpoint included in the updated analysis.
In squamous NSCLC, median OS was 51.3 weeks (95% CI: 18.9–NE). In the EGFR-mutant NSCLC cohort, median OS was 51.9 weeks (95% CI: 19.9–NE).
Median OS had not been reached in the nonsquamous NSCLC cohort without genomic alterations, with a reported 95% CI of 28.4 weeks to NE. In HR+ breast cancer, median OS was 36.4 weeks (95% CI: 36.4–NE), while the cervical cancer cohort had a median OS of 25.9 weeks (95% CI: 16.7–NE).
The number of observed OS events varied across the cohorts, ranging from two in cervical cancer to 11 in squamous NSCLC. These differences, together with the relatively limited size of some groups, should be considered when interpreting the survival findings.
Overall, the efficacy data offer an early view of JK06’s potential across several advanced solid tumors. Additional clinical evaluation will be needed to establish the consistency of these results, identify patient populations most likely to benefit, and determine how the therapy compares with available treatment options.
Safety and Tolerability Profile
Safety remains an important consideration as JK06 advances through clinical development, particularly because patients with advanced cancers may have received several previous therapies.
Among the 230 patients treated within the target dose range of 3.7–5.2 mg/kg, JK06 was generally well tolerated. Treatment-related adverse events (TRAEs) were predominantly low grade and manageable, according to the company.
The median follow-up period for patients in the target-dose population was 35 weeks. During this period, the most frequently reported treatment-related adverse events, each occurring in at least 15% of patients, were:
- Alopecia: 23%
- Peripheral neuropathy: 17%
- Fatigue: 16%
- Asthenia: 15%
Alopecia refers to hair loss, while peripheral neuropathy involves damage or dysfunction affecting peripheral nerves. Fatigue and asthenia describe tiredness and physical weakness, respectively. The incidence of these events will remain relevant as investigators assess the tolerability of JK06 with longer exposure and in combination regimens.
Grade 3 or higher treatment-related adverse events were reported in 9% of patients overall. These more severe events included keratitis in six patients (3%) and peripheral neuropathy in four patients (2%). Asthenia, fatigue, and neutropenia were each reported as Grade 3 or higher events in two patients, representing approximately 1% of the target-dose population for each event.
Keratitis, an inflammation of the cornea, is an important safety event to monitor during treatment. Neutropenia, a reduction in neutrophils that can increase susceptibility to infection, is also clinically relevant in oncology patients. Continued monitoring will help investigators characterize these events and determine appropriate management strategies.
Among the 230 patients, two Grade 4 treatment-related adverse events were reported. No Grade 5 treatment-related adverse events were observed in the target-dose population.
Dose modifications and treatment discontinuations were also reported. A total of 27 patients, or 12%, underwent dose reduction because of treatment-related adverse events. Twelve patients, representing 5% of the population, discontinued treatment because of these events.
Although the findings indicate that most reported treatment-related toxicities were manageable, the safety profile will require continued assessment as the trial progresses. Longer follow-up and larger patient populations will be important for identifying less common adverse events and understanding whether the tolerability profile remains consistent across different cancer types and treatment combinations.
ESMO Congress 2026 Presentation Details
The updated JK06 clinical findings are being presented at the ESMO Congress 2026 in a poster presentation within the Developmental Therapeutics session.
- Presentation title: A Phase 1b/2 Study of JK06, a 5T4-Targeted Antibody Drug Conjugate (ADC), in Patients with Unresectable Locally Advanced or Metastatic Cancer
- Presenter: Emiliano Calvo, M.D., Ph.D., START Center for Cancer Research, Madrid, Spain
- Presentation number: 1013P
- Session: Developmental Therapeutics
- Date: October 23, 2026
- Time: 15:15–16:00 Central European Summer Time (CEST)
- Congress: ESMO Congress 2026, Madrid, Spain, October 23–27, 2026
The presentation provides an opportunity to review the updated clinical experience with JK06 and its potential role in treating advanced solid tumors.
Next Steps for JK06 Development
SalubrisBio intends to continue the Phase 1/2 study, with ongoing enrollment in tumor-specific monotherapy and combination expansion cohorts. The completed dose-escalation stage has established the framework for continued evaluation within the selected dose range, while the expansion cohorts are intended to provide more detailed information about activity and safety in specific cancer populations.
The company is particularly interested in further investigating JK06 in squamous NSCLC, where the updated monotherapy data support consideration of later-stage clinical studies. Additional work will also explore the potential of combining JK06 with immune-based and targeted treatments, which could help determine whether the investigational ADC can contribute to treatment strategies in earlier lines of therapy.
The current findings are encouraging in that responses and disease control have been observed across several tumor types, alongside a safety profile characterized primarily by low-grade treatment-related adverse events. However, the study remains ongoing, and the reported results should be interpreted in the context of the early-phase design, the number of evaluable patients in each cohort, and the duration of follow-up.
Further clinical data will be needed to establish the extent and durability of JK06’s benefit, define its optimal use, and determine whether the observed activity translates into meaningful clinical advantages for patients with advanced cancer.
For now, the updated results presented at ESMO 2026 represent another step in the clinical development of JK06. SalubrisBio’s continued investigation of the therapy as both a monotherapy and a potential combination treatment will help clarify its future role across NSCLC, breast cancer, cervical cancer, and other 5T4-expressing solid tumors.
About JK06
JK06 is a first-in-class quadrivalent, biparatopic ADC that selectively targets 5T4 with a monomethyl auristatin E (MMAE) payload. 5T4 is an oncofetal protein that is overexpressed in a wide range of solid tumors, including non-small cell lung cancer (NSCLC), breast, gastric, and genitourinary cancers, and is associated with more aggressive tumor progression and reduced survival. JK06 has demonstrated picomolar affinity for 5T4 and enhanced internalization resulting from the biparatopic design. Together with stable, site-specific payload conjugation, JK06 has demonstrated the potential for robust efficacy and a favorable safety profile.
About SalubrisBio
SalubrisBio is a clinical-stage biotechnology company dedicated to discovering and developing complex biologics for cardiovascular disease and oncology. The Company is currently progressing multiple innovative and rationally designed first-in-class therapeutics through clinical development programs, including JK07, the potential first disease-modifying biologic for heart failure, and JK06, a quadrivalent, biparatopic ADC targeting 5T4 for the treatment of cancer. SalubrisBio is headquartered in Gaithersburg, Maryland.