Nantkwest Inc. and privately held Immunitybio Inc. trotted out positive early interim results from their advanced metastatic pancreatic cancer studies showing median survival rates more than double the historic rates: eight month’s survival compared to only three.
“Anything beyond three months has an impact,” Patrick Soon-Shiong, Immunitybio’s CEO and Nantkwest’s executive chairman, told BioWorld, with understatement about one of the toughest to manage indications in medicine.
The trials, based on the exploratory Quilt trials initiated in 2017, have the two companies saying they believe survival rates could be improved without high-dose chemotherapy by combining natural killer and T-cell therapy. Avoiding chemotherapy is a prime goal, according to Soon-Shiong, who added he’s unsure if, with chemo, the treatment or the disease is worse.
The initial Cancer Moonshot Quilt trials of haNK combined with PD-L1 inhibitor avelumab wrapped up in 2019. The median overall survival rate in the 12-patient study was three months for historic control vs. eight months in the treatment arm.
The interim study results show a complete remission was achieved when replacing haNK and PD-L1 inhibitor avelumab with PD-L1 t-haNK. Four out of five patients who had not yet reached median survival time, three months, are alive eight to 16 months since beginning treatment on the expanded protocols.
The PD-L1-targeting high-affinity NK cells (PD-L1 t-haNK) treatment also resulted in a complete remission when replacing haNK and PD-L1 checkpoint inhibitor avelumab with PD-L1 t-haNK.
Soon-Shiong said he hopes the new data from the study will be more mature by June, when results could be presented at the American Society of Clinical Oncology’s annual meeting.
The three-cohort pivotal trial, Quilt 88, in metastatic pancreatic cancer is designed to evaluate the comparative efficacy and overall safety of standard-of-care chemotherapy vs. standard-of-care chemotherapy in combination with PD-L1 t-haNK, Anktiva (nogapendekin alfa inbakicept, N-803) and aldoxorubicin in patients with locally advanced or metastatic pancreatic cancer.
The single-arm phase II study (Quilt 88, cohort C) began in October 2020. Its primary endpoint is overall survival. Fifteen of the 18 patients enrolled with second-line or greater pancreatic cancer are still alive. The randomized phase II study (Quilt 88, cohorts A and B) to treat first- and second-line metastatic pancreatic cancer is enrolling patients in Orange County, Calif., Los Angeles and Sioux Falls, S.D.
“Given the relatively early nature of these data it is difficult to draw many conclusions,” wrote Piper Sandler analyst Joseph Catanzaro on Jan. 13. “At minimum, we're very encouraged by the rate of early enrollment and believe cohort C with longer follow-up will provide a sizable and meaningful dataset in 2021 that could drive greater conviction in the potential of the PD-L1 t-haNK regimen in the late-line pancreatic cancer setting.”
Soon-Shiong called the research “an ongoing, real-world, real-time revolution” and that one of its most gratifying aspects is the ability to move quickly between developing molecular insights and their clinical translation. If the data remain encouraging, he added, the treatment could potentially address multiple tumor types. The biology is the same, he added, as the host immune system is being treated, not the disease.
Nantkwest stock (NASDAQ:NK) soared on the news, with shares closing up 20.37% at $17.79. The past 12 months have been strong for the stock. Shares have risen 141% since Jan. 16, 2020, when they went for $7.38 each.
In late December, Immunitybio, of Culver City, Calif., and Nantkwest, of El Segundo, Calif., agreed to merge in a stock-for-stock transaction, creating an immunotherapy and cell therapy company focused on oncology and infectious disease. Immunitybio shareholders will receive a fixed exchange ratio of 0.8190 shares of Nantkwest for each share of Immunitybio owned. Upon completion of the transaction, on a fully diluted basis, Immunitybio shareholders will own about 72% of the combined company.