Benzinga | Dec 10, 2021 08:11AM EST

Intensity Therapeutics Reports Early Efficacy Results Using INT230-6 As A Monotherapy Or In Combination With Pembrolizumab In Metastatic Breast Cancer At 2021 San Antonio Breast Cancer Symposium

Intensity Therapeutics, Inc. ("Intensity"), a clinical-stage biotechnology company focused on the discovery and development of proprietary, novel immune-based intratumoral cancer therapies designed to kill tumors and increase immune system recognition of cancers, today reported safety, pharmacokinetic, biomarker and efficacy data using INT230-6, with and without pembrolizumab, in heavily pretreated refractory breast cancer patients as part of the Company's phase 1/2 study, IT-01. The presentation was made at the San Antonio Breast Cancer Symposium(r) (SABCS), being held virtually and in-person at the Henry B. Gonzales Convention Center in San Antonio, Texas.

The seven heavily pre-treated breast cancer subjects were enrolled in the study after having progressed on a median of six (range 2 to 10) prior therapies. The INT230-6 monotherapy subjects (n=4) were more heavily pre-treated with a median of eight prior therapies vs. three prior therapies for pembrolizumab combination subjects (n=3). The disease control rate (DCR), defined as the percent of breast cancer subjects with a complete response, partial response, or stable disease at the first radiologic assessment, was 57%. Study authors reported a median overall survival (mOS) of 12 months (CI:7.2, NR), which compares favorably to results seen in phase 1 studies of subjects with highly refractory or triple negative breast cancer. Abscopal effects were seen in a non-injected visceral lesion in 1 of 4 INT230-6 monotherapy subjects. A number of patients came off study after completion of INT230-6 dosing without disease progression. One subject continued receiving INT230-6 injections despite a new lesion.

Peak plasma concentrations of the agent vinblastine were less than five percent (5%) of that predicted, based on historical IV kinetics, indicating that 95% of the drug remains in the tumor. Treatment related adverse events (TRAEs) were favorable with or without pembrolizumab. Only one subject experienced a grade 3 TRAE (monotherapy group) and there were no grade 4 or grade 5 TRAEs. Tissue analysis of matched paired (pre- and 28 days post-dose) biopsies in injected tumors from subjects receiving their first INT230-6 treatment cycle (two doses, n=3) had an average reduction in viable cancer cells of sixty-nine percent (69%). Immunohistochemistry results showed influx of CD4 and CD8 T-cells into the tumor microenvironment.

"Preliminary data suggests that INT230-6 demonstrates direct tumor killing in metastatic breast cancer subjects including those with triple negative breast cancer (TNBC) and may elicit an anti-cancer immune response within the injected tumor with or without pembrolizumab," stated poster presenter and study investigator, Philippe Bedard, M.D., Clinician Investigator, Princess Margaret Cancer Centre in Toronto Canada. "Additionally, INT230-6 treatment related adverse events are mostly low grade and the drug is well-tolerated either as a monotherapy or in combination with anti-PD-1 therapy, pembrolizumab. These results provide evidence to continue studying this novel therapeutic drug approach in breast cancer."

"The data presented at the San Antonio Breast Cancer Symposium using INT230-6 alone or in combination with pembrolizumab were generated from refractory breast cancer patients treated in the dose escalation portion of our phase 1 clinical study, IT-01, and these results are encouraging. We have also learned a great deal about our drug in breast cancer from our trial in metastatic patients and our phase 2 randomized INVINCIBLE study, which is testing INT230-6 in breast cancer patients in a presurgical setting," said Lewis H. Bender, President and Chief Executive Officer of Intensity Therapeutics. "We are excited about conducting additional clinical studies using INT230-6 in metastatic breast cancer as part of INT230-6's Fast Track designation as well as in presurgical patients, as there remains an unmet medical need for safer more effective treatments in both settings."



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