Leukocyte Interleukin Injection Immunotherapy Produces Significant Survival Benefit in Landmark Head, Neck Cancer Study

The phase 3 results from a landmark immunotherapy study of the leukocyte interleukin for injection (Multikine; CEL-SCI Corporation) in advanced primary squamous cell carcinoma of the head and neck (SCCHN) found significant 5-year survival benefits, according to the company.

“Based on this landmark study data, we intend to seek FDA approval for what could become the first treatment in newly diagnosed advanced primary head and neck cancer in many decades,” said Geert Kersten, chief executive officer of CEL-SCI, in a press release.

Approximately 60,000 new cases of head and neck cancer are diagnosed in the United States each year, representing 6% of all cancers and 300,000 deaths globally. Advanced primary SCCHN represent approximately 386,000 cases per year. Approximately 40% of these patients are diagnosed at a lower risk of recurrence and are therefore only given radiotherapy following surgery, without chemotherapy.

Leukocyte interleukin for injection is an investigational immunotherapy that contains 14 natural human cytokines, including interleukins, interferons, chemokines, and colony stimulating factors. These are all elements of the body’s natural mix of defenses against cancer, as well as other diseases.

The global phase 3 trial enrolled 928 patients diagnosed with stage III and IVa cancers, with the intent to treat a population comprised of 923 patients. Five patients were randomized but never treated. The 2 main comparator arms were those who received the leukocyte interleukin regimen plus standard of care, compared to those who received standard of care alone.

In intent to treat patients with advanced primary SCCHN, the study investigators found a statistically significant overall survival benefit of 14.1%, with an overall survival rate of 62.7% at 5 years for patients receiving the leukocyte interleukin injection regimen followed by surgery and radiotherapy. The overall survival benefit increased over time, according to the press release.

This patient group represents approximately 155,000 patients worldwide. Patients who were treated with the same leukocyte interleukin regimen prior to surgery and radiotherapy, but who also received chemotherapy, did not exhibit the survival advantage. In these patients, cisplatin was administered intravenously and may have negatively impacted the survival benefit, according to the press release.

“In patients not indicated to receive chemotherapy as part of their standard of care, treatment with [the leukocyte interleukin] neoadjuvant regimen demonstrated a statistically significant, robust, and durable overall survival benefit,” said Eyal Talor, PhD, chief scientific officer of CEL-SCI and developer of the drug, in the press release. “The data possibly indicate that the [leukocyte interleukin] treatment regimen is capable of altering the course of disease in this population.”

When the complete study population receiving the leukocyte interleukin regimen was compared to the control group, the study did not meet its primary endpoint of a 10% improvement in overall survival. However, the overall survival benefit of 14.1% at 5 years for the lower risk subgroup exceeded the 10% goal for the overall population.

Based on these findings, the company plans to seek FDA approval for the immunotherapy in patients with advanced primary SCCHN, which the press release said is an underserved patient population. This indication represents a major unmet medical need because the last FDA approval for this population was several decades ago, according to the press release.

“If approved, [leukocyte interleukin for injection] would address the needs of approximately 155,000 patients diagnosed annually worldwide who are currently slated for surgery plus radiotherapy and would significantly increase their changes of overall survival,” Kersten said in the press release. “Our aim with [this immunotherpay] was to develop a treatment that will extend survival, and clearly this has been achieved in this patient population.”

REFERENCE

CEL-SCI’s Multikine Immunotherapy Produces Significant 14.1% 5-Year Survival Benefit (62.7% Vs 48.6%) in the Group Receiving Surgery Plus Radiotherapy in a Landmark Head and Neck Cancer Phase 3 Study. News release. BusinessWire. June 28, 2021. Accessed July 1, 2021. https://www.businesswire.com/news/home/20210628005472/en/CEL-SCI%E2%80%99s-Multikine%C2%AE-Immunotherapy-Produces-Significant-14.1-5-Year-Survival-Benefit-62.7-Vs-48.6-in-the-Group-Receiving-Surgery-Plus-Radiotherapy-in-a-Landmark-Head-and-Neck-Cancer-Phase-3-Study