For people with both blood cancer and COVID-19, treatment of COVID-19 with blood plasma from COVID-19 survivors, called convalescent plasma, may improve survival, according to a new study from an Advocate Aurora Research Institute investigator.
The retrospective study, recently published in JAMA Oncology, found that, even after adjusting for potential patient differences that may have contributed to different outcomes, patients treated with convalescent plasma had a lower mortality rate after 30 days compared to similar patients who did not receive convalescent plasma.
Additionally, for patients who were admitted to the intensive care unit (ICU) or who required mechanical ventilation, 30-day mortality was lower for convalescent plasma recipients compared to similar nonrecipients.
“From early on in the pandemic, doctors have reported increased COVID-19 mortality in patients with hematologic cancers,” said Advocate Aurora Health oncologist and hematologist Michael Thompson, MD, PhD, the study’s lead author. “If our study results can be confirmed in prospective clinical trials, we believe convalescent plasma would become the first COVID-19 treatment with a survival benefit for these high-risk patients.”
The relationship between hematologic cancers and COVID-19 has become an area of focus for cancer researchers over the past year. Although scientists have found that antibody-based immunity is an important factor in both COVID-19 recovery and prevention against future infections, impaired antibody function is a well-established complication of some blood cancers.
“Hematologic cancers, such as multiple myeloma, chronic lymphocytic leukemia and other lymphoid cancers, are associated with defects in immunity that may contribute to adverse COVID-19 outcomes,” Dr. Thompson said.
Although case reports have noted significant improvement in immunodeficient patients after COVID-19 convalescent plasma therapy, there is still a lack of study data concerning COVID-19 patients with hematologic cancers.
To test their hypothesis that convalescent plasma therapy can correct defects in antibody deficiency and improve COVID-19 outcomes in patients with hematologic cancers, the study authors analyzed data from the COVID-19 and Cancer Consortium (CCC19). CCC19 is a novel crowdsourcing effort designed to rapidly collect clinical and biologic data from cancer patients and survivors with COVID-19 and quickly disseminate results to participating institutions. Advocate Aurora joined CCC19 in April 2020.
The CCC19 data analyzed for the study consisted of 966 hospitalized U.S. adults with a current or past diagnosis of hematologic cancers and confirmed or suspected infection from SARS-COV-2, the virus that causes COVID-19 infection, reported from March 17, 2020, to Jan. 21, 2021.
Because this was a retrospective study and not a randomized controlled trial in which treatment with convalescent plasma would be randomly assigned to different patients, the researchers performed what is called propensity score matching to account for differences in the baseline characteristics of the patients. Propensity score matching reduces the chance that other factors could have a potential effect on the outcome of the study treatment.
The study found that the mortality rate was 13.3% for the 143 convalescent plasma recipients (19 patient deaths within 30 days) compared to 24.8% for the 823 nonrecipients (204 patient deaths within 30 days). The difference between the two groups remained statistically significant after researchers adjusted the data to account for confounding factors using propensity score matching.
Because their study drew from patients treated at numerous institutions, the researchers believe their findings are unlikely to be the result of specific practice patterns at certain institutions.
“People with cancer are some of our most vulnerable patients, and even more so during the COVID-19 pandemic,” said Amit Acharya, PhD, chief research officer and system vice president for Advocate Aurora and the Research Institute. “Through his association with CCC19, Dr. Thompson continues to advance our understanding of how best to treat these patients, and Advocate Aurora and the Research Institute are proud to support his work.”
To learn more about Advocate Aurora’s research, visit aurora.org/research.