Sigvotatug vedotin (formerly known as SGN-B6A | PF-08046047; see ADC Drugmap)*, an investigational integrin beta-6 (IB6)–directed antibody-drug conjugate (ADC), has emerged as a promising therapeutic agent in non-squamous non-small cell lung cancer (NSCLC). [1] Recent topline results from the Phase 3 SigVie-002 (NCT06012435) study evaluated the efficacy and safety of the study drug in patients with previously treated, locally advanced, unresectable, or metastatic NSCLC. While the primary endpoint of overall survival (OS) in the overall population was not met, encouraging signals were observed in key subgroups, supporting further development of this agent in NSCLC and other solid tumors.
Non-squamous NSCLC remains a leading cause of cancer-related mortality worldwide, with limited treatment options for patients who progress after standard therapies [2]. Integrin beta-6 is highly expressed in NSCLC and is associated with poor prognosis, making it an attractive target for novel drug development [3][4].
Sigvotatug vedotin employs a protease-cleavable maleimidocaproyl-valine-citrulline (mc-vc) linker to covalently attach the cytotoxic payload, monomethyl auristatin E (MMAE), to the Integrin beta-6 targeting monoclonal antibody. This mc-vc linker is engineered for high stability in circulation, preventing premature release of MMAE. Upon binding to integrin beta-6 (IB6) and internalization into the tumor cell, intracellular proteases such as cathepsin B cleave the peptide bond, releasing MMAE to disrupt microtubule dynamics and induce cell cycle arrest and apoptosis. The investigational agent is a first-in-class IB6-targeted ADC designed for high selectivity and rapid internalization, potentially limiting off-target toxicity [4].
Study design
The SigVie-002 trial is an open-label, randomized, global Phase 3 study comparing sigvotatug vedotin with docetaxel in 703 adult patients with previously treated (one or more prior lines) locally advanced, unresectable, or metastatic non-squamous NSCLC [5]. Patients were randomized to receive sigvotatug vedotin intravenously (Days 1 and 15 of each 28-day cycle) or docetaxel (Day 1 of each 21-day cycle). The primary endpoint was OS; secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR), assessed by blinded independent central review (BICR) per RECIST v1.1.
Study outcomes
In the overall study population, sigvotatug vedotin did not demonstrate a statistically significant improvement in OS versus docetaxel [4]. However, in patients who received only one prior line of systemic therapy (about two-thirds of the study population), a stronger trend favoring sigvotatug vedotin was observed in both OS and PFS. The safety profile was manageable and consistent with previous studies, with no new safety signals identified [5][6]. Exploratory analyses did not reveal a clear IB6 expression-response relationship.
Phase 1 dose-escalation and expansion studies previously established a manageable safety profile and promising antitumor activity for sigvotatug vedotin, with objective response rates of 19% in the overall population and 29% in taxane-naïve, non-squamous NSCLC [6][7]. Pharmacokinetic modeling supported a dosing regimen of 1.8 mg/kg (adjusted ideal body weight) every two weeks, which is being further investigated.
Challenges and follow-up
The SigVie-002 trial underscores the challenges of improving outcomes in heavily pretreated NSCLC, where docetaxel remains an active comparator [5]. Despite not meeting the primary endpoint in the overall population, the observed efficacy trends in the second-line setting are clinically meaningful and support ongoing clinical evaluation, particularly in combination regimens. Notably, the ability of sigvotatug vedotin to induce immunogenic cell death provides a mechanistic rationale for combination with immune checkpoint inhibitors, an approach being explored in an ongoing Phase 3 trial of sigvotatug vedotin plus pembrolizumab in first-line NSCLC with high PD-L1 expression NCT06758401).[5]
Beyond the above-mentioned indication, Pfizer continues to advance the clinical development of sigvotatug vedotin through multiple ongoing studies across various stages of NSCLC and other IB6-expressing solid tumors. Key programs include a phase III study evaluating sigvotatug vedotin in combination with pembrolizumab (Keytruda®; Merck & Co) as a first-line treatment for advanced NSCLC patients with a PD-L1 tumor proportion score of at least 50%.
Additionally, Pfizer is exploring sigvotatug vedotin in combination with PF-08634404 (also known as SSGJ-707), an investigational tetravalent PD-1 x VEGF bispecific antibody that leverages Common Light Chain Linear Fab x2 (CLF2) technology with an IgG4 backbone.SSGJ-707) is an investigational, tetravalent bispecific antibody in clinical development by Pfizer in collaboration with 3SBio. PF-08634404 is designed to simultaneously inhibit PD-1–mediated T cell dysfunction and VEGF-A–mediated tumor angiogenesis and immune suppression, and has demonstrated promising preclinical and early clinical activity in NSCLC and colorectal cancer. [7] These novel combination strategies aim to enhance anti-tumor efficacy across a range of IB6-expressing solid tumors.
Next steps
While sigvotatug vedotin did not significantly improve OS versus docetaxel in a broad population of previously treated non-squamous NSCLC, meaningful clinical activity in the second-line setting and a manageable safety profile support further investigation. Combination approaches in first-line and earlier treatment settings may unlock its full therapeutic potential.
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Clinical trials
A Study of SGN-B6A Versus Docetaxel in Previously Treated Non-small Cell Lung Cancer – ClinicalTrials.gov ID NCT06012435
This is a Study to Learn About How the Combination of the Study Medicines Sigvotatug Vedotin Plus Pembrolizumab Works in People With Non-small Cell Lung Cancer With High Levels of PD-L1. (Be6A Lung-02) – ClinicalTrials.gov ID NCT06758401
A Study of Sigvotatug Vedotin in Advanced Solid Tumors – ClinicalTrials.gov ID NCT04389632
A Study of SGN-B6A in Chinese Participants With Advanced Solid Tumors – ClinicalTrials.gov ID NCT06549816
Symbiotic-Lung-20: A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Different Anticancer Agents in Advanced Cancers – ClinicalTrials.gov ID NCT07227298
Highlights of prescribing information
Pembrolizumab (Keytruda®; Merck & Co) [Prescribing Information]
References
[1] Sanborn RE, Peters S, Barbie D. Integrin beta-6: Its emerging role as a therapeutic target in solid tumors. Cancer Treat Rev. 2026 May;146:103128. doi: 10.1016/j.ctrv.2026.103128. Epub 2026 Apr 5. PMID: 41990605.
[2] Peters S, Piha-Paul SA, Sehgal K, et al. First-in-Human, Phase I Study of Sigvotatug Vedotin, an Integrin Beta-6-Directed Antibody-Drug Conjugate: Results From Dose Expansion in Advanced Non-Small Cell Lung Cancer. J Clin Oncol. 2026;44(17):1635-1645. doi:10.1200/JCO-25-02016
[3] Lyon RP, Jonas M, Frantz C, et al. SGN-B6A: A New Vedotin Antibody-Drug Conjugate Directed to Integrin Beta-6 for Multiple Carcinoma Indications. Mol Cancer Ther. 2023;22(12):1444-1453. doi:10.1158/1535-7163.MCT-22-0817
[4] Robert P. Lyon, Michael W. Schmitt, Mechthild Jonas, et al. SGN-B6A: A new MMAE ADC targeting integrin beta-6 in multiple carcinoma indications [abstract]. Cancer Res 2020;80(16 Suppl):Abstract nr 2906.
[5] Topline Phase 3 Results for Sigvotatug Vedotin in Previously Treated Metastatic Non-Squamous Non-Small Cell Lung Cancer [Pfizer press release]. June 22, 2026. Last accessed in June 2026
[6] SGN-B6A, an integrin beta-6 (ITGB6)-targeted antibody-drug conjugate (ADC), in patients with advanced solid tumors: Updated results from a phase 1 study (SGNB6A-001). https://ascopubs.org/doi/10.1200/JCO.2023.41.16_suppl.302
[7] ADC Review: Drug Map. Sigvotatug vedotin | SGN-B6A | PF-08046047. https://www.adcreview
[8] Heiser RA, Zuck M, Sakai C, et al. Characterization and functional evaluation of PF-08634404 (SSGJ-707) a tetravalent PD-1 x VEGF bispecific for the treatment of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia, PA: AACR; Cancer Res. 2026;86(7 Suppl):Abstract nr 5541.
Featured image courtesy © 2026 Pfizer. Used with permission
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