What happened

After unveiling impressive early-stage results for a unique multifaceted approach to targeting solid-tumor cancers, NantKwest (NK) saw its shares surge 26.4% by 12:15 p.m. EST on Thursday.

So what

CEO Patrick Soon-Shiong is one of healthcare's most successful entrepreneurs. At NantKwest, he hopes to deliver yet another win for patients and shareholders by combining low-dose chemotherapy and off-the-shelf engineered natural killer (NK) cells with agents that boost a patient's own immune system response. 

A man in a suit soars into the sky using a jet pack.

Image source: Getty Images.

On Wednesday, NantKwest released intriguing results from an early-stage study evaluating 30 patients with solid-tumor cancers who have been heavily pre-treated with existing treatment options. Specifically, NantKwest reported:

  • An 80% disease control rate (DCR) in 4th-line or greater advanced metastatic triple-negative breast cancer.
  • A 90% DCR in 3rd-line or greater pancreatic cancer patients and overall survival of 9.5 months.
  • A 67% DCR in 4th-line or greater advanced metastatic head and neck cancer. 

These results were achieved by administering low-dose chemotherapy; stimulating a T-cell response by delivering an IL-15 fusion protein and tumor antigens using a yeast and adeno-associated viral vaccines; delivering off-the-shelf NK cells engineered to kill cancer cells; and administering a PD-1 checkpoint inhibitor that makes it easier for the immune system to find cancer cells. Soon-Shiong refers to this approach as a "cancer memory vaccine."

Displays the administration cycle of the six cancer fighting therapies administered to patients by NantKwest.

Image source: NantKwest.

Now what:

PD-1 checkpoint inhibitors are hauling in billions of dollars annually in sales, but many people don't respond to them, and their benefit falls over time in patients who do. Similarly, chemotherapy can produce remission, but it can be highly toxic, and doesn't work for everyone. Additionally, gene therapy -- including chimeric antigen receptor T-cell therapies that engineer T-cells to find and kill cancer cells -- have limited efficacy in solid-tumor cancers, and they can cause life-threatening cytokine storms. 

There's obviously a need for new treatment approaches that work better, and NantKwest's early results suggest Soon-Shiong's team is on to something. But this approach still needs more study in more patients to confirm results, demonstrate durability, and prove its safety. 

Nevertheless, Soon-Shiong has proved he can build successful biotechnology companies (he sold Abraxis to Celgene for $2.9 billion in 2010), and he's very experienced in cancer research. So it may be worth giving him the benefit of the doubt. If you do, just remember that NantKwest is a high-risk company, and over 90% of cancer therapies fail in clinical-stage trials.