On October 30, 2025 Intensity Therapeutics, Inc. (Nasdaq: INTS) ("Intensity" or "the Company"), a late-stage clinical biotechnology company focused on the discovery and development of proprietary cancer therapies using its non-covalent, drug-conjugation technology that creates drug products designed to kill tumors and increase immune system recognition of cancers, reported that eBioMedicine, a Lancet Discovery Science journal, has published the Company’s phase 1/2 IT-01 clinical study manuscript for the treatment of metastatic or refractory cancers. The full text article, "Safety and Efficacy of Intratumourally Administered INT230-6 in Adult Patients with Advanced Solid Tumours: Results from an Open-Label Phase 1/2 Dose Escalation Study," can be viewed via Online First 105980 October 29, 2025.
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Jacob Stephen Thomas, M.D. Assistant Professor of Clinical Medicine at Keck School of Medicine of the University of Southern California (USC) and medical oncologist with USC’s Norris Comprehensive Cancer Center, is the first author. Anthony El-Khoueiry, M.D., Associate Director for Clinical Research and Chief of Section of Developmental Therapeutics/Phase I Program at USC Norris, is the senior and corresponding author.
The manuscript includes the following data results:
In heavily pretreated patients with advanced disease having over 20 different types of cancer who had progressed following multiple prior lines of therapy, intratumoral INT230-6 achieved:
A disease control rate of 75% (48/64 patients) and median overall survival (mOS) of 11.9 months; these results compare favorably in phase 1/2 studies that historically reported an mOS of 4 to 7 months
In a metastatic sarcoma subset population receiving only INT230-6, the median overall survival was 21.3 months
In an exploratory analysis comparing patients receiving INT230-6 at a total dose (in mL) that treated greater than 40% of the patient’s total tumour burden ("TTB") compared to those treated with less than 40% of their TTB, the:
Disease control rate was 83.3% (40/48) compared to 50% (8/16)
Median overall survival was 18.7 months (95% CI: 11.5–23.5) compared to 3.1 months (95% CI: 1.6–5.9) with a hazard ratio (HR) of 0.17 (95% CI: 0.081–0.342); P<0.0001 (see Figure 1 below)
Improved survival was consistent across a range of low to high tumor burden and tumor sizes
Approximately 20% of patients in the >40% group had uninjected tumors shrink, abscopal effects
Fifteen of 64 patients survived for more than 21 months
INT230-6 induced a qualitative decrease in proliferating cancer cells in injected tumors and a qualitative increase in activated T-cells infiltrating the tumor microenvironment
No dose-limiting toxicities were reported among 64 monotherapy patients; seven patients had a grade 3 (10.9%) with no grade 4 or 5 treatment-related adverse events
Pharmacokinetic results showed that greater than 95% of the active cytotoxic agents remained in the injected tumors
"INT230-6 is a local treatment that kills cancer using a diffusion process following direct injection into tumors. The trial demonstrated favorable safety and promising efficacy in patients with advanced metastatic cancers who had failed a median of three prior lines of therapy. The disease control rates and median survival compare favorably to those historically seen for such a diverse set of refractory cancer types in a phase 1/2 study," said Jacob S. Thomas, M.D. "There were also several learnings about INT230-6 dosing and safety gained during this trial. The pharmacokinetic data indicated that high rates of the drug are absorbed by the injected tumor, with minimal leakage, even at doses as high as 175 mL administered to a single tumor. These results are consistent with the low incidence of grade 3 adverse events observed."
"The mechanism by which cancer is killed through the diffusion of cytotoxic agents following intratumoral injection of INT230-6 and systemic immune activation, as observed in preclinical models, translated well in the human setting. Uninjected tumors shrinking from a locally administered therapy, referred to as abscopal effects, are generally rare for local therapies. Yet, an abscopal effect was observed in at least 20% of 48 patients who received drug volumes above 40% of their tumor burden. In addition, in thirteen of fourteen matched pair biopsy slides, a notable increase in activated CD4+ and CD8+ T cells was observed in the tumor microenvironment in response to INT230-6 treatment. Representative images can be found in the paper," said Anthony El-Khoueiry M.D. "The abscopal effects and immune cell infiltration observed in this study highlight this intratumoral therapy’s potential to drive both a local and systemic anti-cancer activity."
"This comprehensive paper is the culmination of over a decade of nonclinical and clinical research. The article describes the development of a new technology to destroy tumors using molecular agents that can disperse potent anti-cancer compounds within injected tumors and deliver them into cancer cells. We believe these are the first clinical results where a locally administered therapy used alone could potentially extend survival for patients with metastatic disease," said Lewis H. Bender, Founder, President, and CEO of Intensity Therapeutics, Inc. "As Drs. Thomas and El-Khoueiry noted, our paper reports that INT230-6 injected into visible tumors in metastatic patients at an amount based on the size of the injected tumors supports the hypothesis that INT230-6 causes immunologic cancer cell death, even in cancers that are considered immunologically cold. Given the drug’s mechanism of action and the data reported in this paper from over 20 types of metastatic solid cancers, such as breast, sarcoma, pancreatic, lung, and head and neck, we believe the study results show the potential of INT230-6 to achieve clinical benefit for metastatic patients of multiple cancer types with or without the use of radiation, systemic drugs or immunotherapy. As a result, we have initiated randomized controlled studies, including a Phase 3 study in sarcoma (NCT06263231)."
The Company will be hosting a conference call featuring two key authors of the study on Friday, October 31, 2025 at 9:00AM ET to discuss the results. Interested parties can access the call by clicking here: View Source Participants are encouraged to log on at least 10 minutes prior to the start of the event.
About INT230-6
INT230-6, Intensity’s lead proprietary investigational product candidate, is designed for direct intratumoral injection. INT230-6 was discovered using Intensity’s proprietary DfuseRx℠ technology platform. The drug consists of two proven, potent anti-cancer agents, cisplatin and vinblastine sulfate, and a diffusion and cell penetration enhancer molecule ("SHAO") that non-covalently conjugates to the two payload drugs, facilitating the dispersion of potent cytotoxic drugs throughout tumors and allowing the active agents to diffuse into cancer cells. These agents remain in the tumor, resulting in a favorable safety profile. In addition to local disease control and direct tumor killing, INT230-6 causes a release of a bolus of neoantigens specific to the malignancy, leading to immune system engagement and systemic anti-tumor effects. Importantly, these effects are mediated without immunosuppression, which often occurs with systemic chemotherapy.
(Press release, Intensity Therapeutics, OCT 30, 2025, View Source [SID1234657177])
About Study Intensity’s Clinical Study IT-01
IT-01 was Intensity’s first-in-human, open-label, single-arm phase 1/2 study (NCT03058289) using INT230-6. The study was conducted in patients with advanced, refractory, or metastatic solid tumors at six clinical sites in addition to USC. Other investigators were from Johns Hopkins University, Princess Margaret Hospital in Toronto, Columbia Presbyterian in New York, The Fox Chase Cancer Center in Philadelphia, Houston Methodist, and UMass Memorial. The study was comprised of adults with histologically or cytologically confirmed advanced or metastatic solid tumors who did not respond to or were not candidates for standard therapies and had accessible superficial and/or deep tumors for injection. Dose escalation was achieved by increasing the initial and subsequent total dose volumes (total injected amount), the maximum injected volume per any single tumor, the ratio of drug-volume to tumor-size, the number of injected tumors per session, and the dose frequency (once per month vs. every 2 weeks). Maintenance dosing was added in protocol amendments. A tumor’s dose was set as a percentage of the volume of the target tumor, which was calculated from radiologic measurements. There were six monotherapy dose cohorts.