The following article features coverage from the ASCO Genitourinary Cancers Symposium 2022. Click here to read more of Cancer Therapy Advisor’s conference coverage.

Among patients with solid tumors, those receiving immunotherapy have a more durable immune response to COVID-19 vaccination, a new study suggests.

The study showed less durable responses for patients receiving chemotherapy or targeted therapy. The results were presented in a poster at the ASCO Genitourinary Cancers Symposium 2022.

For this study, researchers evaluated the immune response to COVID-19 vaccination in 61 patients with solid tumors who were receiving anticancer therapies.


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The most common tumor types were renal (n=19), breast (n=16), bladder (n=7), and lung (n=7). The types of anticancer therapy received included chemotherapy (n=29), immunotherapy (n=19), and targeted therapy (n=13).

Most patients received the AstraZeneca vaccine (n=36), followed by the Pfizer-BioNTech vaccine (n=23), and the Moderna vaccine (n=1). A second vaccine dose was administered within 12 weeks of the first dose and followed by a third booster dose.

Serum samples were collected at 4 time points — before the second dose, at 14-36 days after the second dose, at 36-63 days after the second dose, and within 30 days of the third dose.

The researchers measured serum anti-SARS-CoV-2 spike protein (anti-S) antibody titers, and seroconversion was defined as a response of at least 0.8 U/ml. A maximum response was defined as at least 250 U/ml.

Seroconversion and Response Over Time

Seroconversion after the first dose occurred in 100% of patients in the immunotherapy group, 85% of those in the targeted therapy group, and 82% of those in the chemotherapy group.

Patients in all 3 treatment groups saw an increase in mean anti-S titers between the first and second time points. However, that increase was smaller in the chemotherapy group than in the immunotherapy and targeted therapy groups.

Between the first and second time points, there was a significant difference in the proportion of patients achieving a maximum antibody response for both the immunotherapy (P =.0005) and targeted therapy (P =.001) groups, but the difference was not significant for the chemotherapy group (P =.06).

Before the second dose, a maximum response was seen in 21% of patients in the immunotherapy group, 15% in the targeted therapy group, and 24% in the chemotherapy group.

At 14-36 days after the second dose, a maximum response was seen in 83% of patients in the immunotherapy group, 69% in the targeted therapy group, and 54% in the chemotherapy group.

At 36-63 days after the second dose, there was a significant difference in mean anti-S titers between the chemotherapy and immunotherapy groups — 214.3 and 138.6, respectively (P <.05). This suggests a greater need for a third vaccine dose in the chemotherapy group, according to the researchers.

Within 30 days of a third dose, a maximum response was seen in 93% of patients in the immunotherapy and chemotherapy groups and 100% of patients in the targeted therapy group.

“Immunologic response to COVID-19 vaccination is dependent on type of systemic anticancer therapy,” the researchers concluded. “The third booster vaccine dose appears particularly relevant for chemotherapy patients, compared to those receiving immune therapy or targeted therapies. COVID-19 shielding guidelines and booster dose guidance should be tailored according to treatment group.”

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Read more of Cancer Therapy Advisor’s coverage of ASCO GU 2022 by visiting the conference page.

Reference

Jackson-Spence F, Toms C, Yang Y-H, et al. The effect of anti-cancer therapy on immunologic response to COVID-19 vaccination. Presented at ASCO GU 2022; February 17-19, 2022. Abstract 319.