Conference Coverage

Immune checkpoint inhibitors don’t increase COVID-19 incidence or mortality, studies suggest



Immune checkpoint inhibitor (ICI) therapy does not increase the risk of developing or dying from COVID-19, according to a pair of studies presented at the Society for Immunotherapy of Cancer’s 35th Anniversary Annual Meeting.

Cytokine storm plays a major role in the pathogenesis of COVID-19, according to research published in The Lancet Respiratory Medicine. This has generated concern about using ICIs during the pandemic, given their immunostimulatory activity and the risk of immune-related adverse effects.

However, two retrospective studies suggest ICIs do not increase the risk of developing COVID-19 or dying from the disease.

In a study of 1,545 cancer patients prescribed ICIs and 20,418 matched controls, the incidence of COVID-19 was 1.4% with ICI therapy and 1.0% without it (odds ratio, 1.38; P = .15).

In a case-control study of 50 patients with cancer and COVID-19, 28% of patients who had received ICIs died from COVID-19, compared with 36% of patients who had not received ICIs (OR, 0.36; P = .23).

Vartan Pahalyants and Kevin Tyan, both students in Harvard University’s joint MD/MBA program in Boston, presented these studies at the meeting.

COVID-19 incidence with ICIs

Mr. Pahalyants and colleagues analyzed data from cancer patients treated in the Mass General Brigham health care system. The researchers compared 1,545 patients with at least one ICI prescription between July 1, 2019, and Feb. 29, 2020, with 20,418 matched cancer patients not prescribed ICIs. The team assessed COVID-19 incidence based on positive test results through June 19, 2020, from public health data.

Vartan Pahalyants, a student in Harvard University's joint MD/MBA program

Vartan Pahalyants

The incidence of COVID-19 was low in both groups – 1.4% in the ICI group and 1.0% in the matched control group (P = .16). Among COVID-19–positive patients, the all-cause death rate was 40.9% in the ICI group and 28.6% in the control group (P = .23).

In multivariate analysis, patients prescribed ICIs did not have a significantly elevated risk for COVID-19 relative to peers not prescribed ICIs (OR, 1.38; P = .15). However, risk was significantly increased for female patients (OR, 1.74; P < .001), those living in a town or county with higher COVID-19 positivity rate (OR, 1.59; P < .001), and those with severe comorbidity (vs. mild or moderate; OR, 9.77; P = .02).

Among COVID-19–positive patients, those prescribed ICIs did not have a significantly elevated risk for all-cause mortality (OR, 1.60; P = .71), but male sex and lower income were associated with an increased risk of death.

“We did not identify an increased risk of [COVID-19] diagnosis among patients prescribed ICIs compared to the controls,” Mr. Pahalyants said. “This information may assist patients and their providers in decision-making around continuation of therapy during this protracted pandemic. However, more research needs to be conducted to determine potential behavioral and testing factors that may have affected COVID-19 diagnosis susceptibility among patients included in the study.”

COVID-19 mortality with ICIs

For their study, Mr. Tyan and colleagues identified 25 cancer patients who had received ICIs in the year before a COVID-19 diagnosis between March 20, 2020, and June 3, 2020, at the Dana-Farber Cancer Institute and Mass General Brigham network. The researchers then matched each patient with a cancer patient having a COVID-19 diagnosis who had not received ICIs during the preceding year.

Kevin Tyan, a student in Harvard University's joint MD/MBA program

Kevin Tyan

Overall, 28% of patients who had received ICIs before their COVID-19 diagnosis died from COVID-19, compared with 36% of those who had not received ICIs.

In multivariate analysis, ICI therapy did not predict COVID-19 mortality (OR, 0.36; P = .23). However, the risk of death from COVID-19 increased with age (OR, 1.14; P = .01) and for patients with chronic obstructive pulmonary disease (OR, 12.26; P = .01), and risk was lower for statin users (OR, 0.08; P = .02). Findings were similar in an analysis restricted to hospitalized patients in the ICI group and their matched controls.

Two ICI-treated patients with COVID-19 had persistent immune-related adverse events (hypophysitis in both cases), and one ICI-treated patient developed a new immune-related adverse event (hypothyroidism).

At COVID-19 presentation, relative to counterparts who had not received ICIs, patients who had received ICIs had higher platelet counts (P = .017) and higher D-dimer levels (P = .037). In the context of similar levels of other biomarkers, this finding is “of unclear significance, as all deaths in the cohort were due to respiratory failure as opposed to hypercoagulability,” Mr. Tyan said.

The patients treated with ICIs were more likely to die from COVID-19 if they had elevated troponin levels (P = .01), whereas no such association was seen for those not treated with ICIs.

“We found that ICI therapy is not associated with greater risk for COVID-19 mortality. Our period of follow-up was relatively short, but we did not observe a high incidence of new or persistent immune-related adverse events among our patients taking ICIs,” Mr. Tyan said.

“While larger prospective trials are needed to evaluate long-term safety in the context of COVID-19 infection, our findings support the continuation of ICI therapy during the pandemic as it does not appear to worsen outcomes for cancer patients,” he concluded.

ICI therapy can continue, with precautions

“The question of susceptibility to COVID-19 has been unclear as ICIs do not necessarily cause immunosuppression but certainly result in modulation of a patient’s immune system,” said Deborah Doroshow, MD, PhD, assistant professor at the Tisch Cancer Institute Icahn School of Medicine at Mount Sinai, New York. She was not involved in these studies.

“The findings of the study by Pahalyants and colleagues, which used a very large sample size, appear to convincingly demonstrate that ICI receipt is not associated with an increased susceptibility to COVID-19,” Dr. Doroshow said in an interview.

Deborah Doroshow, MD, PhD, of Mount Sinai, New York

Dr. Deborah Doroshow

However, the findings of the study by Tyan and colleagues are more “thought-provoking,” Dr. Doroshow said. She noted that a large study published in Nature Medicine showed previous ICI therapy in cancer patients with COVID-19 increased the risk for hospitalization or severe COVID-19 requiring high-flow oxygen or mechanical ventilation. The new study was much smaller and did not perform statistical comparisons for outcomes such as oxygen requirements.

“I would feel comfortable telling patients that the data suggests that ICI treatment does not increase their risk of COVID-19. However, if they were to be diagnosed with COVID-19, it is unclear whether their previous ICI treatment increases their risk for poor outcomes,” Dr. Doroshow said.

“I would feel comfortable continuing to treat patients with ICIs at this time, but because we know that patients with cancer are generally more likely to develop COVID-19 and have poor outcomes, it is critical that our patients be educated about social distancing and mask wearing to the extent that their living and working situations permit,” she added.

Mr. Pahalyants disclosed no relevant conflicts of interest, and his study did not receive any specific funding. Mr. Tyan disclosed that he is cofounder and chief science officer of Kinnos, and his study did not receive any specific funding. Dr. Doroshow disclosed no relevant conflicts of interest.

SOURCE: Pahalyants V et al. SITC 2020, Abstract 826. Tyan K et al. SITC 2020, Abstract 481.

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