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Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) patients are faced with the challenging reality that vaccines may not offer robust protection against COVID-19. However, we are now lucky to have the option of receiving passive immunity through the use of pre-made cloned battle-proven fighters, better known as monoclonal antibodies (mAbs), in some circumstances. Those circumstances may now be expanding.
Casirivimab and Imdevimab (REGEN-COV) and other mAbs have been authorized for early outpatient treatment for COVID-19 infection, as well as post-exposure prophylaxis to prevent catching the disease.
The Nov. 8th press release from Regeneron offers the promise, that Casirivimab and Imdevimab also might be effective for pre-exposure prophylaxis (PrEP) without needing the currently authorized administration protocol of monthly dosing.
Quoting the news release:
“A single dose of REGEN-COV (1,200 mg given subcutaneously) reduced the risk of COVID-19 by 81.6% during the pre-specified follow-up period (months 2-8), maintaining the 81.4% risk reduction previously reported during month one. During the 8-month assessment period, there were zero hospitalizations for COVID-19 in the REGEN-COV group and 6 in the placebo group.”
While some patients are already receiving Casirivimab and Imdevimab monthly for long-term COVID-19 protection either due to recurrent ongoing exposure risk, or through the compassionate use program, these findings raise the possibility of stretching the time between doses, and hopefully with FDA authorization, the broader use of the antibodies used as PrEP for the vulnerable patient populations, such as those of us with CLL.
This is an open PrEP trial designed specifically for the immunocompromised: A Study to Evaluate Efficacy and Safety of Casirivimab+Imdevimab (Monoclonal Antibodies) for Prevention of COVID-19 in Immunocompromised Adolescents and Adults that CLL Society recommends be considered.
For more on the important topic of passive versus active immunity, please read Chronic Lymphocytic Leukemia (CLL) Patients and Protection Against COVID-19: Passive and Active Immunity, Monoclonal Antibodies, and Vaccines.
For more on the latest expanded authorization for Casirivimab and Imdevimab, please see FDA Okays Regeneron COVID-19 Antibody as Preventive for Chronic Lymphocytic Leukemia (CLL) and other Immunocompromised Patients.
Things are moving very fast now when it comes to COVID-19, and that’s good news. Understanding PrEP and having equitable access to newly authorized therapies will be important for all CLL patients as the pandemic continues on. CLL Society is working tirelessly on these goals.
Stay strong. We are all in this together.
Brian Koffman MDCM (retired) MSEd
Co-Founder, Executive VP and Chief Medical Officer
CLL Society, Inc.