Intensity Therapeutics, Inc. to Present INVINCIBLE-4 Neoadjuvant Triple-Negative Breast Cancer Study Data for the First Seven (7) Patients After INT230-6 Treatment (Cohort A) in an ePoster Presentation at the European Society of Medical Oncology (ESMO) Meeting

• Pathological complete response (pCR) achieved in the breast (ypT0/Tis) and affected lymph nodes (ypN0) in 5 out of 7 patients (71%; 95% CI 29-96%) in the INT230-6 plus standard-of-care cohort
  
  
• No invasive breast cancer cells were detected in the axillary lymph nodes in 6 of the 7 INT230-6 patients after INT230-6 treatment, despite 5 (71%) of the patients were initially biopsy-proven node-positive

SHELTON, Conn., Oct. 23, 2026 /PRNewswire/ -- 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, announced data for the first seven patients in Cohort A in the INVINCIBLE-4 Study will be presented in an ePoster by The Swiss Cancer Institute, the Company's collaborator in the INVINCIBLE-4 Study, at the ESMO 2026 Virtual Congress Platform beginning on Friday, 23 October at 08:00 CEST. The Congress is being held at IFEMA Madrid, Spain. The presentation will be available to all registered delegates, both those attending in person and those attending online.

INVINCIBLE-4 (SAKK 66/22) is a randomized, open-label multicenter phase 2 clinical study. There are two cohorts designed to determine the clinical activity, safety, and tolerability of INT230-6 in patients with early-stage, operable TNBC: (i) INT230-6 in combination with standard-of-care neoadjuvant immuno-chemotherapy (NAIC) (Cohort A), and (ii) NAIC alone (Cohort B).

Early activity signals of INT230-6 efficacy in Cohort A are encouraging, with pCR achieved in the breast (ypT0/Tis) and affected lymph nodes (ypN0) in 5 of 7 patients (71%; 95% CI 29-96%). No invasive breast cancer cells were detected in the axillary lymph nodes in 6 of the 7 INT230-6 patients in Cohort A after INT230-6 treatment, despite 5 (71%) being initially biopsy-proven node-positive.

Results also show tumor necrosis after 1 or 2 injections in all 7 Cohort A patients. In the pre-surgery MRI at the completion of NAIC four (57%) patients had RECIST 1.1 radiological complete response and three patients (43%) partial response.

Below are MRI images at 3 timepoints for one Cohort A patient who had 2 injections. This patient achieved a radiological and pathological complete response (CR).

All 7 patients in Cohort A met the criteria for breast-conserving surgery, but one proceeded with mastectomy owing to a high-risk germline mutation. Six (85%) patients had sentinel lymph node biopsy and targeted axillary dissection. One (14%) patient had axillary lymph node dissection. The INT230-6 dose was associated with dose-limiting local skin reactions. All other adverse events in Cohort A were low grade (< 2). The protocol was amended to one injection at a lower drug volume to tumor volume ratio.

The trial includes patients with newly diagnosed, previously untreated, locally advanced non-metastatic TNBC stage cT1c N1-3 M0 or cT2-4c N0-3 M0 per American Joint Committee on Cancer (AJCC) version 8, defining TNBC as 0% ER/PgR and HER2-negative. Multifocal and multicentric primary tumors are allowed. Patients must have measurable disease in the breast with at least one lesion with a diameter ≥1.5 cm that is evaluable per RECIST v1.1, visible in ultrasound and injectable.

About Triple Negative Breast Cancer in the Presurgical Setting

Women with aggressive forms of breast cancer, such as TNBC, are often counseled to undergo neoadjuvant (presurgical) systemic therapy to reduce the risk of the disease returning. Having a pathological complete response, meaning the absence of live cancer at the time of surgery, has been shown to result in a lower risk of disease recurrence from 50% to 16% at 5 years. Approximately 11% to 17% of breast cancers test negative for estrogen receptors (ER), progesterone receptors (PR), and overexpression of human epidermal growth factor receptor 2 (HER2) protein, qualifying them as triple negative. There are approximately 56,000 new cases of TNBC in the U.S. and 420,000 worldwide diagnosed each year, 85% of which are local to the breast. TNBC is considered to be more aggressive and has a poorer prognosis than other types of breast cancer, because there are fewer available targeted medicines. Most patients with local TNBC typically receive immunochemotherapy before surgery. Since the publication of Keynote-522, the standard neoadjuvant treatment for TNBC includes systemic chemotherapy (anthracyclines, cyclophosphamide, paclitaxel, carboplatin) and the anti-PD-1 monoclonal antibody pembrolizumab. pCR rates range from 50% to 65%, depending on tumor size. Rates are generally lower in the larger-sized tumors or with lymph node metastasis. The toxicity of the Keynote-522 regimen is high, with 77% of patients experiencing grade 3 or higher treatment-related AEs, including treatment-related adverse events that lead to death in 0.5% of patients.

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.

About Intensity Therapeutics

Intensity is a late-stage clinical biotechnology company whose novel engineered chemistry enables aqueous cytotoxic-containing drug formulations to mix and saturate a tumor's dense, high-fat, pressurized environment following direct intratumoral injection. As a result of the saturation, Intensity's clinical trials have demonstrated the ability of INT230-6 to kill tumors and elicit an adaptive immune response within days of injection, representing a new approach to cancer cell death that holds the potential to shift the treatment paradigm and turn many deadly cancers into chronic diseases, even for malignancies that do not respond to conventional immunotherapy. Intensity has completed two clinical studies that enrolled over 200 patients using INT230-6: a Phase 1/2 dose-escalation study in metastatic cancers including sarcomas (NCT03058289), and a Phase 2 randomized controlled clinical trial in locally advanced breast cancer (the "INVINCIBLE-2 Study") (NCT04781725) in women without undergoing chemotherapy prior to their surgery. The Company initiated a Phase 3 trial in soft tissue sarcoma (the "INVINCIBLE-3 Study") (NCT06263231), testing INT230-6 as second- or third-line monotherapy compared with SOC, with overall survival as an endpoint. Intensity also initiated a Phase 2 study in collaboration with The Swiss Group for Clinical Cancer Research, formerly SAKK and now the Swiss Cancer Institute (the "INVINCIBLE-4 Study") (NCT06358573), as part of a Phase 2/3 program evaluating INT230-6 followed by SOC immunochemotherapy and SOC alone for patients with presurgical triple-negative breast cancer. pCR is the endpoint. For more information about Intensity, including publications, papers, and posters about its novel approach to cancer therapeutics, visit www.intensitytherapeutics.com or review our SEC filings.

Forward-Looking Statements

Certain statements in this press release may constitute "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995, as amended to date. These statements include, but are not limited to, statements relating to the Company's expected future plans, cash runway, development activities, projected milestones, business activities or results. When or if used in this communication, the words "may," "could," "should," "anticipate," "believe," "estimate," "expect," "intend," "plan," "predict" and similar expressions and their variants, as they relate to the Company or its management, may identify forward-looking statements. The forward-looking statements contained in this press release are based on management's current expectations and projections about future events. Nevertheless, actual results or events could differ materially from the plans, intentions, and expectations disclosed in, or implied by, the forward-looking statements. These risks and uncertainties, many of which are beyond our control, include: the initiation, timing, progress and results of future preclinical studies and clinical trials and research and development programs; the need to raise additional funding before the Company can expect to generate any revenues from product sales; plans to develop and commercialize product candidates; the timing or likelihood of regulatory filings and approvals; the ability of the Company's research to generate and advance additional product candidates; the risk that product candidates that appear promising in early research and clinical trials do not demonstrate safety and/or efficacy in larger-scale or later clinical trials; the implementation of the Company's business model, strategic plans for the Company's business, product candidates and technology; commercialization, marketing and manufacturing capabilities and strategy; the rate and degree of market acceptance and clinical utility of the Company's system; the Company's competitive position; the Company's intellectual property position; developments and projections relating to the Company's competitors and its industry; the Company's ability to maintain and establish collaborations or obtain additional funding; expectations related to the use of cash and cash equivalents and investments; our potential inability to satisfy the Nasdaq Capital Market's requirements for continued listing and be subject to delisting; estimates regarding expenses, future revenue, capital requirements and needs for additional financing; and other risks described in the section entitled "Risk Factors" in the Company's Annual Report on Form 10-K for the year ended December 31, 2025 and in the Company's subsequent SEC filings, which can be obtained on the SEC website at www.sec.gov. Readers are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date on which they are made and reflect management's current estimates, projections, expectations and beliefs. The Company does not plan to update any such forward-looking statements and expressly disclaims any duty to update the information contained in this press release except as required by law.

Investor Relations Contact:

Justin Kulik
CORE IR
[email protected]
(516) 222-2560

Media Contact:

Matt Cossel
CORE IR
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SOURCE Intensity Therapeutics Inc.