CULVER CITY, Calif.--(BUSINESS WIRE)--ImmunityBio, Inc., a privately-held immunotherapy company, today announced the oral presentation of “Phase II/III clinical results of IL-15RαFc superagonist N-803 with BCG in BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) carcinoma in situ (CIS) patients (Cohort A)” during a session at the Genitourinary Cancers Symposium sponsored by the American Society of Clinical Oncology (ASCO).
The data showed 51 out of 72 evaluable patients (71%), with 10.7 months median follow-up, had a complete response at any time to intravesical BCG plus N-803, also called Anktiva™ (95% confidence interval), meeting the primary endpoint of the study. In addition, the study showed 59% probability of these patients maintaining a complete response for at least 12 months, with an estimated median duration of complete response of 19.2 months to date using Kaplan-Meier methods.
“The high rates of complete response without serious adverse events indicates that the combination of BCG plus N-803 is a promising alternative to existing therapies and compares favorably to the other approved options valrubicin and pembrolizumab,” said presenting author Karim Chamie, M.D., Associate Professor of Urology, David Geffen School of Medicine at UCLA.
No immune-related adverse events were seen in any patients, and only 1% of patients reported treatment emergent serious adverse events, but none of which were treatment-related. Additionally, 24% of patients received additional chemotherapy and other therapies (excluding BCG) between last dose of BCG and study entry, and 100% of patients received prior BCG, thus the data support the potential for Anktiva plus BCG as a novel option for BCG unresponsive CIS, a therapeutically challenging disease. Patients with BCG unresponsive CIS disease face surgical removal of the bladder, a procedure fraught with high morbidity and mortality.
Bladder cancer has a high incidence worldwide; it caused 212,536 deaths and an estimated 573,278 new cases were diagnosed in 20201. In the United States, bladder cancer is the fourth most commonly diagnosed solid malignancy in men and the twelfth for women; The American Cancer Society estimates 80,470 new cases and 17,670 deaths in 20192. Approximately 75-85% of all newly diagnosed cases of bladder cancer are non-muscle invasive bladder cancer (NMIBC)3.
The open-label, three cohort multicenter Phase 2/3 study of intravesical BCG plus Anktiva (N-803) in patients with BCG-unresponsive high-grade NMIBC (NCT03022825) was opened in 2017. The primary endpoint for Cohort A of this Phase 2/3 study is incidence of complete response (CR) of CIS at any time. The FDA had granted Fast Track Designation to the pivotal trial based on Phase I data. In December 2019, the FDA granted ImmunityBio Breakthrough Therapy Designation based on interim Phase 2 data indicating the primary endpoint of the trial was already met.
ImmunityBio’s IL-15 superagonist Anktiva (N-803)
The cytokine interleukin-15 (IL-15) plays a crucial role in the immune system by affecting the development, maintenance, and function of the natural killer (NK) and T cells. N-803 is a novel IL-15 superagonist complex consisting of an IL-15 mutant (IL-15N72D) bound to an IL-15 receptor α/IgG1 Fc fusion protein. N-803 has improved pharmacokinetic properties, longer persistence in lymphoid tissues and enhanced anti-tumor activity compared to native, non-complexed IL-15 in vivo.
N-803 is currently being evaluated for adult patients in two clinical NMIBC trials. QUILT 2.005 is investigating use of N-803 in combination with BCG for patients with BCG-naïve NMIBC; QUILT 3.032 is studying N-803 in combination with BCG in patients with BCG-unresponsive NMIBC.
The Urgent, Unmet Need to Treat NMIBC and Avoid Cystectomy
For the last 30 years, BCG immunotherapy has been the standard for treating NMIBC. However, disease recurrence and progression rates remain unacceptably high. Standard of care recommendations for these patients include lifetime invasive surveillance and rapid treatment of recurrences, creating a substantial financial burden and drastic impact on quality of life. Of those patients who experience recurrence, approximately 30% will progress and succumb to their disease over a 15-year period, and another 50% will undergo radical cystectomy of the bladder in an attempt to control their disease4.
For high-risk NMIBC patients who are BCG-unresponsive with persistent or recurrent disease, treatment guidelines recommend a surgical procedure called radical cystectomy, a surgery to remove the entire bladder that may require removal of other surrounding organs. In men, removal of the prostate may be necessary, and in women, surgeons may also remove the uterus, fallopian tubes, ovaries and cervix, and occasionally a portion of the vagina. Despite the advent of minimally invasive procedures and robotic techniques, the 90-day mortality and morbidity rates in patients who undergo cystectomy remain unacceptably high at 5.1-8.1% and 28-64%, respectively5. Based on this urgent need, FDA published guidance in February 2018 to address BCG unresponsive non-muscle invasive bladder cancer (NMIBC), stating that the goal of therapy in patients with BCG-unresponsive NMIBC is to avoid cystectomy.
ImmunityBio separately announced today that it has entered into an agreement to combine in a stock-for-stock transaction with NantKwest, Inc. (NASDAQ: NK). The combination will create a leading immunotherapy and cell therapy companies focused on oncology and infectious disease.
ImmunityBio, Inc. is a late-clinical-stage immunotherapy company developing next-generation therapies that drive immunogenic mechanisms for defeating cancers and infectious diseases. The company’s immunotherapy platform activates both the innate (natural killer cell and macrophage) and adaptive (T-cell) immune systems to create long-term “immunological memory.” This novel approach is designed to eliminate the need for high-dose chemotherapy, improve upon the outcomes of current CAR T-cell therapies, and extend beyond checkpoint inhibitors.
ImmunityBio’s platform is based on the foundation of three separate modalities: antibody cytokine fusion proteins, synthetic immunomodulators, and second-generation human adenovirus (hAd5) vaccine technologies.
Anktiva™ (ImmunityBio’s lead cytokine infusion protein) is a novel interleukin-15 (IL-15) superagonist complex and has received Breakthrough Therapy and Fast Track Designations from the U.S. Food and Drug Administration (FDA) for BCG-unresponsive CIS non-muscle invasive bladder cancer (NMIBC). The company is also in Phase 2 or 3 trials for indications such as first- and second-line lung cancer, triple-negative breast cancer, metastatic pancreatic cancer, recurrent glioblastoma, and soft tissue sarcoma in combination with the company’s synthetic immune modulator (Aldoxorubicin).
ImmunityBio is also developing therapies, including vaccines, for the prevention and treatment of HIV, influenza, and the coronavirus SARS-CoV-2 with its second-generation human adenovirus (hAd5) vaccine technologies.
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Certain information contained in this communication relates to or is based on studies, publications, surveys and other data obtained from third-party sources and NantKwest’s and ImmunityBio’s own internal estimates and research. While NantKwest and ImmunityBio believe these third-party sources to be reliable as of the date of this communication, it has not independently verified, and makes no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. In addition, all of the market data included in this communication involves a number of assumptions and limitations, and there can be no guarantee as to the accuracy or reliability of such assumptions. Finally, while NantKwest and ImmunityBio each believes its own internal research is reliable, such research has not verified by any independent source.
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In connection with the proposed transaction, NantKwest filed with the SEC a registration statement on Form S-4, which included a prospectus and joint proxy / solicitation statement of NantKwest and ImmunityBio (the “solicitation statement/prospectus”). The registration statement was declared effective on February 1, 2021 and the solicitation statement/prospectus was first mailed to stockholders of NantKwest on or about February 5, 2021. NantKwest may also file other documents regarding the proposed transaction with the SEC. This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. This communication is not intended to be, and is not, a substitute for such filings or for any other document that NantKwest may file with the SEC in connection with the proposed transaction. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, INVESTORS AND SECURITY HOLDERS ARE URGED TO CAREFULLY READ THE ENTIRE REGISTRATION STATEMENT AND SOLICITATION STATEMENT / PROSPECTUS, AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION. Investors and security holders are able to obtain free copies of the registration statement and solicitation statement/prospectus and other documents once they are filed with the SEC by NantKwest through the website maintained by the SEC at www.sec.gov. In addition, investors and security holders are able to obtain free copies of the prospectus and other documents filed with the SEC on NantKwest’s website at https://ir.nantkwest.com.
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- Global cancer statistics: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries: https://gco.iarc.fr/