Terrestrial Bio has dosed the first participants in a Phase 1 trial of VX-201, a needle-free Tacterra™ microarray patch delivering semaglutide, evaluating safety, tolerability, and pharmacologic performance against subcutaneous injections.
Written By: Anshu Gupta, PharmD
Reviewed By: Pharmacally Editorial Team
Terrestrial Bio has dosed the first participants in a Phase 1 clinical trial evaluating VX-201, an investigational needle-free microarray patch that delivers semaglutide. The study marks the company’s first clinical evaluation of its Tacterra™ Microarray Patch platform and will assess whether patch-based administration can achieve systemic drug exposure comparable to subcutaneous injections while maintaining acceptable safety and tolerability.
Tacterra platform aims to simplify GLP-1 delivery
Semaglutide, the active ingredient in Wegovy®, has become a cornerstone therapy for obesity and other metabolic disorders. However, weekly injections, needle-related discomfort, and cold-chain distribution requirements remain barriers to long-term adherence and broader access.
VX-201 delivers semaglutide through dissolvable microneedles embedded in a microarray patch. The patch is applied using a spring-loaded applicator, and the microneedle bases dissolve within approximately five minutes, leaving drug-loaded tips in the upper layers of the skin to release semaglutide. By eliminating conventional injections, the technology could improve patient acceptance while potentially simplifying storage and distribution.
Phase 1 trial evaluates single and multiple-dose treatment
The first-in-human study is being conducted at a single U.S. clinical site and plans to enroll approximately 62 healthy adults aged 18 to 60 years with a body mass index (BMI) of 25–40 kg/m².
The trial consists of two parts.
The single ascending dose phase will enroll 32 participants across 0.25 mg and 0.5 mg dose cohorts. Participants will be randomized 1:1 to receive either VX-201 or a reference subcutaneous Wegovy® injection.
The multiple-dose phase will enroll 30 participants who first complete a 12-week semaglutide subcutaneous dose-escalation regimen. Participants will then be randomized 1:1 to receive either VX-201 or maintenance-dose subcutaneous semaglutide at 1.7 mg or 2.4 mg for an additional eight weeks.
The primary endpoints focus on safety and tolerability, including assessment of skin sensitivity at the patch application site.
Early evidence supports clinical advancement
The Phase 1 program builds on encouraging preclinical and human factors data generated with the Tacterra platform.
At the 2025 American Diabetes Association (ADA) Scientific Sessions, Terrestrial reported preclinical findings showing that its microarray patch achieved semaglutide bioavailability comparable to subcutaneous injection. Separately, a human factors study published in December 2025 found that 95% of participants preferred the Tacterra microarray patch applicator over traditional injection devices, including the Ozempic® prefilled pen.
Together, these findings provided the rationale for advancing VX-201 into clinical testing.
Leadership highlights patient experience and clinical validation
Rachel Sha, Chief Executive Officer of Terrestrial Bio, said GLP-1 therapies have transformed metabolic disease management but noted that injections and cold-chain logistics continue to create challenges for patients and healthcare systems. She said initiating first-in-human testing represents an important step toward offering a more convenient patch-based alternative.
Lynda Tussey, PhD, Chief Development Officer, said VX-201 is intended to achieve systemic semaglutide exposure comparable to injectable therapy while improving the treatment experience. She added that encouraging preclinical findings supported progression into clinical development, where the company will now generate the evidence needed to evaluate the platform’s safety and performance.
Regulatory Path Forward
Results from this Phase 1 study will determine whether the Tacterra Microarray Patch can safely deliver semaglutide with pharmacologic performance comparable to injectable therapy. Positive findings would support further clinical development of VX-201 and could establish dissolvable microarray patches as a new delivery approach for GLP-1 medicines used in obesity and metabolic disease.
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About the Writer
Anshu Gupta (LinkedIn) is a PharmD professional and healthcare writer with interests in clinical research, pharmacovigilance, regulatory affairs, and medical writing. She has presented research at academic conferences and completed certifications in Good Clinical Practice (GCP), ICH-GCP, and drug safety. Passionate about clinical trials and evidence-based medicine, she is committed to translating scientific evidence into accurate, reliable, and accessible healthcare content.