RS Research Announces Successful Completion of Phase 1 Clinical Trial of RS-0139 in Solid Tumors
7 May 2026
- Topline results from the Phase 1 trial of RS-0139 in patients with solid tumors suggests an improved therapeutic index in a real-world oncology setting.
- RS Research’s proprietary platform, Sagitta®, demonstrated selective delivery of docetaxel to tumor tissue, supporting its broader translational potential across other drugs.
- With successful results from Phase 1, the company is preparing for an international Phase 2 program expected to start in Q1 2027.
- The company plans to present more detailed trial data at upcoming conferences throughout the year, as it prepares for a Series B financing to advance RS-0139 and other assets in clinical trials.
Istanbul & Lausanne, May 7, 2026 – RS Research, a biotechnology company developing smart nanomedicines for oncology, has announced the successful completion of the Phase 1 clinical trial of its lead investigational candidate, RS-0139, in patients with solid tumors. Designed on the company’s proprietary Sagitta® platform to selectively deliver docetaxel to tumor tissue and improve therapeutic index, RS-0139 has now generated early clinical evidence supporting not only its own continued advancement, but also the broader translational potential of the Sagitta® platform. This milestone marks an important inflection point for RS Research as it prepares for the next stage of development, including international clinical expansion, strategic partnering and future financing discussions.
The completed Phase 1 clinical study was a multicenter, open-label, two-step Phase 1a/1b trial conducted to determine the optimal dose and characterize the pharmacokinetic, safety and tolerability profile of RS-0139 in patients with recurrent, locally advanced or metastatic solid tumors. The study generated the initial clinical dataset needed to assess how Sagitta®-enabled targeted delivery may translate into an improved therapeutic index in a real-world oncology setting.
Key findings from the Phase 1 trial include:
- markedly improved hematologic safety compared with conventional chemotherapy,
- an encouraging overall safety and tolerability profile,
- promising early signals of antitumor activity.
RS Research is currently consolidating the full clinical dataset and completing the relevant procedural steps in preparation for future scientific and corporate disclosure of additional details.
Prof. Rana Sanyal, Co-Founder and CSO of RS Research, and Grand Prize Laureate of the EIC European Prize for Women Innovators, said: “These results are the product of years of rigorous science, persistence and translational focus. More importantly, they provide early clinical validation of our Sagitta® platform, supporting our confidence that targeted delivery can meaningfully improve the therapeutic index of oncology treatments. This milestone strengthens our conviction in advancing additional candidates built on the same platform.”
Sagitta® is RS Research’s proprietary drug delivery platform, designed to improve therapeutic index by selectively directing cytotoxic payloads to tumor tissue and addressing the longstanding efficacy-toxicity trade-off in solid tumors. The platform is highly versatile and can be seamlessly ornamented with targeting moieties across a broad molecular spectrum, from peptides to full-length proteins and monoclonal antibodies.
Gulsah Nomak, MD, Medical Director of RS Research, stated: “The successful completion of the Phase 1 program provides the clinical foundation for our next stage of development. It supports our plans to advance RS-0139 into an international Phase 2 program designed to further define its therapeutic potential in solid tumors.”
Dr. Sena Nomak, Co-Founder and COO of RS Research, added: “This milestone marks an important point of transition for RS Research as we move from early clinical validation toward broader international development. We have secured over 20 million USD backing so far from pharma, VC and non-dilutive funding sources. It strengthens our position in ongoing strategic discussions around the company’s global growth trajectory and comes at a meaningful inflection point as we prepare for our upcoming Series B financing round.”
About the Phase 1 Clinical Trial of RS-0139
The completed Phase 1 clinical program for RS-0139 included both dose-escalation and dose-expansion stages and marked the completion of enrollment and dosing across the full study. Conducted at two clinical sites in patients with recurrent, locally advanced or metastatic solid tumors, the trial was designed to generate the clinical foundation for subsequent development of RS-0139 while further strengthening the company’s translational and operational readiness for the next phase. ClinicalTrials.gov identifier: NCT04261413.
About the Sagitta® platform
The Sagitta® nanocarrier family is a clinically validated, polymer-drug conjugate platform designed to revolutionize targeted oncology therapy by solving the efficacy-toxicity trade-off. Sagitta® is compatible with a broad spectrum of conjugation technologies, including diverse targeting ligands, monoclonal antibodies, and cleavable linkers. Our lead candidate, RS-0139, was developed with Sagitta® Bir, a water-soluble, biocompatible polymer backbone that forms stable nanocarriers for enhanced payload integrity and tumor delivery. For more information on the other Sagitta technologies, please visit our website.
About RS Research
RS Research is a clinical-stage biotechnology company focused on the discovery and development of smart nanomedicines for targeted therapies in oncology. Through Sagitta®, its proprietary drug delivery platform, the company is advancing a pipeline of investigational candidates to improve therapeutic index, disrupt the efficacy-toxicity trade-off, and enable new treatment approaches across solid tumors. Since inception, RS Research has secured over 20 million USD backing from a diverse syndicate spanning strategic pharmaceutical investors, venture capital and non-dilutive funding sources. The company holds SME status with the European Medicines Agency (EMA) and operates its own GMP-certified production facility supporting its clinical development activities and international growth plans.
Contact:
E-mail: ozgecesur@rsresearch.net
Tel: +905356551155
URL: www.rsresearch.net
