Benzinga | Jun 15, 2021 07:05AM EDT

FDA Authorizes ImmunityBio's Study Of Anktiva And PD-L1 t-haNK To Increase Effectiveness Of Trodelvy In Triple-Negative Breast Cancer

* Open-label Phase 1b/2 study will evaluate the safety and preliminary efficacy of Anktiva (N-803) and PD-L1 t-haNK in combination with antibody-drug conjugate Trodelvy and low-dose chemotherapy in subjects with advanced triple-negative breast cancer (TNBC) after prior therapy The FDA approved Trodelvy for TNBC in April 2020 based on an overall response rate of 33.3%, with a median duration of response of 7.7 months; 55.6% maintained their response for 6 or more months and 16.7% maintained their response for 12 or more months. Study design is based on results of Phase 1 trial of haNK cells combined with Anktiva and low dose chemo in refractory triple negative breast cancer, where disease control rate of 78% and overall response rate of 67% was reached Enrollment expected to begin in Q3 2021 ImmunityBio, Inc. (NASDAQ:IBRX), a clinical-stage immunotherapy company, today announced it has received FDA authorization to conduct a Phase 1b/2 open-label study to evaluate the safety and preliminary efficacy of its superagonist Anktiva (N-803, an IL-15 superagonist) and PD-L1 targeted high-affinity natural killer (t-haNK) cells in combination with standard chemo and Trodelvy (sacituzumab govitecan-hziy), in subjects with advanced triple-negative breast cancer (TNBC). The study may provide data indicating whether this combination can increase the effectiveness of Trodelvy in patients who have failed to respond to other treatments. Triple-negative breast cancer is a serious, aggressive cancer with a high mortality rate. While Trodelvy displayed efficacy against TNBC in phase 3 testing, only a third of third-line patients respond to it, and less than 17% of them continue to respond after a year. ImmunityBio proposed this new study based on data from a Phase 1 trial (NCT03387085) with Anktiva and the company's haNK cells that elicited a significant response rate in refractory TNBC. Anktiva and PD-L1 t-haNK when used in combination with Trodelvy may show additive or even synergistic effects, greatly increasing the response rate and, importantly, durability of responses. "Antibody-drug conjugates like Trodelvy have made tremendous progress in giving patients with TNBC more and higher-quality time, but we believe Anktiva could potentially fill remaining treatment gaps and offer patients additional hope," said Patrick Soon-Shiong, M.D., Founder and Executive Chairman of ImmunityBio. "We're conducting multiple studies with Anktiva across different tumor types, in some cases in combination with our NK cell line, that are designed to determine if they can enhance the activity of therapeutic monoclonal antibodies like Trodelvy--and, ultimately, provide patients with longer, progression-free survival." The strategy behind this approach is to attack the tumor in two distinct, complementary ways--with Trodelvy delivering the initial blow by targeting the protein Trop-2 displayed by many TNBC cells and delivering a chemotherapy payload while Anktiva recruits key cells of the immune system, including NK and T cells, to continue fighting the tumor. To further unleash the power of the immune system, PD-L1 t-haNK will be introduced. QUILT 3.058 Study Details This phase 1b/2 open-label study will evaluate the safety and efficacy of sacituzumab govitecan-hziy in combination with chemoimmunotherapy (cyclophosphamide, N-803, and PD-L1 t-haNK) in subjects with TNBC after at least two prior treatments for metastatic disease. The study consists of two phases and the maximum total enrollment for this study is 79 subjects. The phase 1b portion of the study will be conducted in 2 parts: part 1 will involve dose escalation using a 3 + 3 design, and part 2 will involve the expansion of the recommended phase 2 dose (RP2D) to further evaluate the safety and efficacy of sacituzumab govitecan-hziy plus chemoimmunotherapy. The phase 2 portion of the study will be based on Simon's two-stage optimal design. In phases 1b and 2, all subjects will receive sacituzumab govitecan-hziy plus chemo- and immuno-therapy: cyclophosphamide, N-803, and PD-L1 t-haNK on a 3-week schedule. . The dose of sacituzumab govitecan-hziy will be dependent on dose level cohort for phase 1b and will be set at the RP2D for phase 2. The doses of cyclophosphamide, N-803, and PDL1 t haNK will remain the same in all dose level cohorts and phases. An estimated 2.3 million women globally were diagnosed with breast cancer last year and 685,000 died from it. Triple negative breast cancer is an especially aggressive form of the disease and accounts for 10% to 15% of breast cancers, according to the American Cancer Society.TNBC tests negative for estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor 2 (HER2) protein. Therefore, TNBC does not respond to hormonal therapy or medicines that target ER, PR, or HER2 and other treatment options are limited, particularly after initial lines of therapy have failed. Innovative treatment approaches, such as the combination of Trodelvy, Anktiva, and PD-L1 t-haNK with chemotherapy described here may offer new hope to these advanced TNBC patients.