Shaky stats
The most important news in healthcare: Friday, April 2nd
Today’s story is at first a rather puzzling case – a small company, Delcath Systems, announced positive data for its new medical device, and yet its stock plummeted. If that’s not adding up to you, read on – we’ve done the math and shown our work, too.
Today’s Pulse is 600 words, or a 5 minute read.
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MEDICAL DEVICESPreliminary data announced for new liver tumor drug-device
The pulse:
On Wednesday, Delcath Systems announced that its liver tumor treatment device, Hepzato, had shown promising results in a clinical trial. So why did Delcath shares drop 44% on the news?
The device:
Hepzato is a drug-device combination product, designed to treat metastatic ocular melanoma that has spread to the liver. The target population is quite small – there are only about 5,000 cases of ocular melanoma diagnosed each year in the U.S; about half of these cases spread to the liver. However, if Hepzato is shown to be effective in metastatic ocular melanoma, Delcath would likely aim to expand use to other types of liver tumors.
The device, pictured below, works by temporarily isolating the liver from the rest of the circulatory system using a minimally invasive technique. While the liver is cut off from the rest of the body, a chemotherapy agent called melphalan is infused directly into the liver. This allows for delivery of high levels of chemotherapy to the tumor while minimizing the toxic effects to the rest of the body as usually seen with systemic chemo. A prior version of the device was rejected by the FDA in 2013, as the filter did not adequately prevent melphalan from entering the bloodstream, leading to undesirable side effects.
Source: Delcath Systems
The trial:
The latest Phase 3 clinical trial, FOCUS, used a new and improved version of Hepzato (including a new filtration system) in 90 patients with metastatic ocular melanoma. The FOCUS trial was a single arm trial, meaning all patients were treated with Hepzato and there was no control group. Delcath used a “predefined success criteria” of a 21% response rate.
The data:
Delcath released preliminary data based on analysis of 79 patients in the trial. The average response rate was 29%, meaning 29% of patients saw their tumors shrink. This includes 7% of patients who had a complete response, or no detectable cancer after treatment.
So why is this bad news for shareholders?
Unfortunately, because of the small sample size and lack of a control group, the statistics are a little shaky. Though Delcath announced an average of a 29% response rate, which surpassed their 21% bar, the real number could range anywhere between 20-40%. This wide confidence interval has caused some regulators to question whether more data is needed in more patients before approval can be granted. Delcath has submitted its data to the FDA, and we’ll be awaiting their final word.
Bottom line it for me:
Delcath likely jumped the gun here, releasing preliminary data on a subset of an already small trial. Clinical trial design matters, and investors took note.
In other news…
Pfizer announced that its vaccine was found to be 100% effective in preventing symptomatic COVID-19 infections in children aged 12-15. This is by far the best data from any trial, though the reason for the extremely high efficacy rate in adolescents remains unclear.
Many healthcare workers in Italy have refused their COVID-19 vaccines, even as hospital acquired infections continue to crop up. In response, Italy’s Prime Minister, Mario Draghi, has issued a new decree requiring healthcare workers to be vaccinated against COVID-19.
Findings from a clinical trial published in the New England Journal of Medicine on Wednesday may point to a major breakthrough in esophageal cancer. Nivolumab, a targeted therapy approved for lymphoma, melanoma, and colorectal cancer, also appears to increase disease-free survival in esophageal cancer.