Histopathology and Tumor Biomarker Analysis Confirm CEL-SCI’s Multikine Significantly Prolonged Overall Survival in Head & Neck Cancer—Phase 3 Data Presented at ESTRO 2023

Rhea-AI Summary

CEL-SCI Corporation presented the latest results from its Phase 3 study of Multikine at the ESTRO 2023 Congress. The study showed improved 5-year survival, progression-free survival, and local regional control in Multikine-treated subjects compared to control subjects. The tumor and tumor microenvironment changes induced by Multikine explain the positive outcomes seen. CEL-SCI plans to file for regulatory approval in the U.S., Canada, and Europe.

Positive

• Improved 5-year survival benefit of 14.1% in Multikine-treated subjects
• Improved progression-free survival and local regional control
• Significantly lowered death rate in Multikine-treated subjects

Negative

• None.

Histopathology analysis confirmed improved 5-year survival in Multikine-treated subjects, showed improved progression free survival and improved local regional control, and significantly lowered death rate compared to control subjects who received standard of care alone

VIENNA, Va.--(BUSINESS WIRE)-- CEL-SCI Corporation (NYSE American: CVM) today announced that the latest results from its pivotal Phase 3 study of Multikine, a presurgical cancer immunotherapy, were presented at the European Society for Radiotherapy and Oncology (ESTRO) 2023 Congress in Vienna, Austria in a poster presentation titled “Histopathology population (HPP) confirms Multikine* [Leukocyte Interleukin Injection (LI)] treatment (Tx) outcome in naïve locally advanced primary head & neck squamous cell carcinoma SCCHN)” during the Head & Neck Cancer Session on Saturday, May 13, 2023.

CEL-SCI’s IT-MATTERS pivotal Phase 3 study, the largest study ever conducted in newly diagnosed locally advanced squamous cell carcinoma of the head and neck, reported a statistically significant 14.1% absolute 5-year overall survival benefit in the intent to treat (ITT) subjects who were categorized as lower risk to recurrence (LR) per National Comprehensive Cancer Network (NCCN) guidelines and received Multikine followed by surgery and radiotherapy, as compared to control LR subjects who received only standard of care (SOC) (surgery plus radiotherapy).

The ESTRO presentation focused on pathology analysis of Phase 3 patients’ tumors at surgery. In summary, it confirmed that Multikine pre-surgery treatment led to significant changes in the tumors of the patients treated with Multikine and that these changes were not seen in control patients who did not get Multikine. The tumor tissue and biomarker analyses demonstrated that these changes were statistically significant and important in bringing about the beneficial responses seen. The tumor and tumor microenvironment changes induced by Multikine explain the increased survival, improved progression free survival, and improved local regional control, as well as the significantly lowered death rate compared to control subjects in the study.

These findings from the Phase 3 study also confirm Multikine’s mechanism of action which was previously determined from samples collected during Phase 2 studies from Multikine treated subjects. The results from the Phase 2 studies were previously reported in the Journal of Clinical Oncology (Timar et al).

The ESTRO presentation reported that patient responses to Multikine were determined following 3 weeks of Multikine treatment by comparing baseline tumor/lymph node measurements at screening (per RECIST) with tumor/lymph node measurements made just prior to and confirmed by pathology following surgery. Histopathology (HP) samples (n=453), were representative of the study ITT population (n=923) in all manner of subjects’ characteristics, and showed that:

• Multikine treated subjects had a different tumor and tumor microenvironment cellular profile at surgery than that exhibited by SOC (control) treated subjects. This was determined by pathologists who were blinded to the study using predefined low/high thresholds for 20 biomarkers (5 tumor, 15 tumor microenvironment).
• The histopathology analysis showed association with improved overall survival, progression free survival and local regional control that significantly favored Multikine-treated [(61/279 or 21.9% >> 2.5% by chance alone) vs SOC-treated (5/279 (or 1.9% < 2.5% by chance alone)] (conditional binomial; p<0.0001).
• HP LR Multikine-treated vs HP LR SOC 5-year efficacy measures of success were:
  • Overall Survival of 63.9% vs 44.4% (hazard ratio: 0.64 [95% CI 0.41, 1.01])
  • Progression Free Survival of 56.9% vs 41.1% (hazard ratio 0.67 [95% CI 0.44, 1.02])
  • Local Regional Control of 73.1% vs 63.6% (hazard ratio 0.62 [95% CI 0.35,1.09])
  • HP LR Multikine-treated subjects had a significantly lower (39.1% [45/115]) death rate versus a 53.7% (51/95) death rate for HP LR SOC alone (two-sided Fisher Exact Test p=0.038)

These statistical results for the HP LR analyzed subjects are supportive of the efficacy advantages demonstrated for LR Multikine-treated vs LR SOC alone treated patients in the Phase 3 study.

“We are building a growing body of peer-reviewed data that points to the efficacy of Multikine in advanced primary head and neck cancer in the hopes that a population of patients, for whom no new treatment options have been forthcoming in more than five decades, may soon benefit from a longer and better life. Based on the totality of the data, we are preparing to file for regulatory approval, including through accelerated and early access pathways, in the U.S., Canada, and Europe,” stated CEL-SCI CEO, Geert Kersten. “ESTRO 2023 marks our fourth presentation of the Phase 3 study data at a major global peer-reviewed cancer conference in the past twelve months.”

About CEL-SCI Corporation

CEL-SCI believes that boosting a patient’s immune system while it is still intact should provide the greatest possible impact on survival. Therefore, in the Phase 3 study, CEL-SCI studied patients who were newly diagnosed with locally advanced primary squamous cell carcinoma of the head and neck with the investigational product Multikine first, BEFORE they received surgery and radiotherapy or surgery plus concurrent radiotherapy and chemotherapy (the current standard of care for these patients). This approach is unique. Most other cancer immunotherapies are administered only after conventional therapies have been tried and/or failed. Multikine (Leukocyte Interleukin, Injection) received Orphan Drug designation from the FDA for neoadjuvant therapy in patients with squamous cell carcinoma (cancer) of the head and neck. CEL-SCI believes that this Phase 3 study is the largest Phase 3 study in the world for the treatment of locally advanced primary head and neck cancer.

Multikine is designed to help the immune system “target” the tumor at a time when the immune system is still relatively intact and thereby thought to be better able to mount an attack on the tumor. The Phase 3 study was started in early 2011 and was fully enrolled with 928 patients in September 2016. To test for an overall survival benefit, the study required CEL-SCI to wait until at least 298 (deaths) events had occurred among the two main comparator groups.

The Company has operations in Vienna, Virginia, and near/in Baltimore, Maryland.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. When used in this press release, the words "intends," "believes," "anticipated," "plans" and "expects," and similar expressions, are intended to identify forward-looking statements. Such statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected. Such statements include, but are not limited to, statements about the terms, expected proceeds, use of proceeds and closing of the offering. Factors that could cause or contribute to such differences include an inability to duplicate the clinical results demonstrated in clinical studies, timely development of any potential products that can be shown to be safe and effective, receiving necessary regulatory approvals, difficulties in manufacturing any of the Company's potential products, inability to raise the necessary capital and the risk factors set forth from time to time in CEL-SCI's filings with the Securities and Exchange Commission, including but not limited to its report on Form 10-K for the year ended September 30, 2022. The Company undertakes no obligation to publicly release the result of any revision to these forward-looking statements which may be made to reflect the events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.

* Multikine (Leukocyte Interleukin, Injection) is the trademark that CEL-SCI has registered for this investigational therapy. This proprietary name is subject to FDA review in connection with the Company's future anticipated regulatory submission for approval. Multikine has not been licensed or approved for sale, barter or exchange by the FDA or any other regulatory agency. Similarly, its safety or efficacy has not been established for any use.

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Gavin de Windt

CEL-SCI Corporation

(703) 506-9460

Source: CEL-SCI Corporation

FAQ

What were the results of CEL-SCI's Phase 3 study of Multikine?

The study showed improved 5-year survival, progression-free survival, and local regional control in Multikine-treated subjects compared to control subjects.

What are the implications of the tumor and tumor microenvironment changes induced by Multikine?

The changes explain the increased survival, improved progression-free survival, and improved local regional control observed in the study.

What are CEL-SCI's plans following these results?

CEL-SCI plans to file for regulatory approval in the U.S., Canada, and Europe.