Salubris Biotherapeutics Announces Updated Phase 1b/2 Data for JK06, a 5T4-Targeted Antibody Drug Conjugate, at the European Society for Medical Oncology Congress 2026

JK06 continued to demonstrate a highly differentiated safety profile for an MMAE ADC among 230 patients in the target dose range; predominantly low-grade, manageable treatment-related adverse events (TRAEs) were observed with low rates of dose reduction and discontinuation

Among response-evaluable squamous non-small cell lung cancer (NSCLC) patients, objective response rate (ORR) of 22% (7 of 32), disease control rate of 84%, median duration of response of 5.2 months, and median progression-free survival of 5.1 months were observed

ORR of 33% (9 of 27) among response-evaluable hormone receptor-positive (HR+) breast cancer patients and 33% (6 of 18) among response-evaluable cervical cancer patients

GAITHERSBURG, Md.--(BUSINESS WIRE)--Salubris Biotherapeutics, Inc. (SalubrisBio), a clinical-stage biotechnology company dedicated to discovering and developing novel complex biologic therapeutics, today announced updated data from the Phase 1b/2 study of JK06, a 5T4-targeted antibody drug conjugate (ADC), in patients with unresectable locally advanced or metastatic solid tumors, including non-small cell lung cancer (NSCLC) and breast cancer. The data are being presented at the European Society for Medical Oncology (ESMO) Congress 2026, taking place October 23-27, 2026, in Madrid, Spain.

“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,” said Sam Murphy, Chief Executive Officer of Salubris Biotherapeutics. “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.”

The ongoing Phase 1/2, open-label study (NCT06667960) included a dose escalation stage which has concluded; the study is currently enrolling multiple tumor-specific monotherapy and combination expansion cohorts in NSCLC, breast cancer, cervical cancer, and a basket of other 5T4-expressing tumors. JK06 is administered intravenously once every three weeks (Q3W), with responses assessed per RECIST 1.1. As of September 21, 2026, 249 patients have been treated with JK06, including 42 patients in dose escalation and 207 patients in expansion cohorts. Overall, 230 patients have been treated in the target dose range of 3.7 – 5.2 mg/kg, including 109 NSCLC patients and 68 breast cancer patients.

Key Efficacy Findings in the Target Dose Range (3.7 – 5.2 mg/kg):

JKO6	NSCLC			Breast Cancer	Cervical Cancer
	Squamous (n = 41)	Nonsquamous w/o genomic alterations (n = 23)	EGFR Mutant (n = 32)	HR+ (n = 28)	(n = 19)
Median Prior Lines of Therapy	2	2	2	5	2
Response Evaluable	32	23	21	27	18
Objective Response Rate (%)	22%	22%	19%	33%	33%
Disease Control Rate (%)	84%	61%	57%	59%	72%
Median Duration of Response, weeks (95% CI)	22.6 (18.3, NE)	16.4 (9.0, NE)	18.3 (18.3, NE)	NE (9.1, NE)	NE
PFS: Number of Events	19	20	15	15	8
Median, weeks (95% CI)	22.1 (17.3, 31.4)	15.0 (9.1, 19.1)	17.4 (7.1, 30.4)	18.1 (8.6, NE)	17.7 (9.7, NE)
OS: Number of Events	11	6	5	6	2
Median, weeks (95% CI)	51.3 (18.9, NE)	NE (28.4, NE)	51.9 (19.9, NE)	36.4 (36.4, NE)	25.9 (16.7, NE)

Key Safety Findings in the Target Dose Range (n=230; 3.7 – 5.2 mg/kg):

• JK06 at doses of 3.7 - 5.2 mg/kg was generally well-tolerated, with treatment-related adverse events (TRAEs) that were predominantly low grade and manageable.
• Median follow-up time was 35 weeks for the target dose range.
• The most frequently observed TRAEs (≥ 15% overall) were alopecia (23%), peripheral neuropathy (17%), fatigue (16%), and asthenia (15%).
• TRAEs ≥Grade 3 were uncommon, and included keratitis (n=6, 3%), peripheral neuropathy (n=4, 2%), and two cases each of asthenia (1%), fatigue (1%), and neutropenia (1%).
• TRAEs ≥Grade 3 were observed in 9% of patients overall, with only two Grade 4 events among 230 patients and no Grade 5 events.
• 27 patients out of 230 (12%) underwent dose reduction, and 12 out of 230 (5%) patients discontinued due to TRAEs.

Details of the ESMO presentation are as follows:

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 #: 1013P
Session: Developmental Therapeutics
Date/Time: October 23, 2026 | 15:15 – 16:00 CEST

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. For more information about SalubrisBio, visit us at www.salubrisbio.com and connect with us on LinkedIn.