Older age and imatinib treatment associated with COVID-19 mortality in CML

The ongoing CANDID study represents the largest global cohort study to date characterising COVID-19 in chronic myeloid leukaemia (CML) patients. The SARS-CoV-2 infection may be asymptomatic in CML patients. Symptomatic COVID-19 in CML patients is mild to moderate in the majority (~80%). However, the mortality rate of CML patients with severe COVID-19 was 63% [1].

Age and certain comorbid conditions, including haematologic malignancies, are associated with an increased risk of developing severe COVID-19 [2]. Thus, data on specific malignancies is essential to decipher the impact of patient-, disease-, and therapy-related factors on COVID-19 outcomes [1]. Dr Delphine Rea (Université de Paris, France) presented the CANDID study, a non-interventional retrospective and prospective study, aimed to analyse characteristics of COVID-19 among CML patients. The international CML Foundation (iCMLf) sent an anonymised case collection form to its global network of CML-treating physicians and partner organisations. In total, 110 cases of COVID-19 were reported to iCMLf from 20 countries: 61% from Europe, 15% from Asia, 12% from South America, 10% from North America, 2% from Africa, and 1% from Oceania. In the 102 symptomatic patients (93%), COVID-19 was considered mild (i.e. no hospitalisation) in 45%, moderate (i.e. hospitalisation) in 17%, severe (i.e. intensive care) in 17%, and of unknown severity in 14%.

The mortality rate from COVID-19 in evaluable CML patients was 13.7%. Factors associated with a higher mortality rate were:

• older age: 75 years 60% versus <75 years 7% (P<0.001);
• severity of COVID-19: severe 63% versus non-severe 0% (P<0.001); and
• imatinib treatment: imatinib 25% versus 2^nd generation tyrosine kinase inhibitor (TKI) 3% versus no TKI 0% (P=0.003).

However, imatinib may represent a confounder rather than a true adverse prognostic predictor considering the strong link between imatinib treatment and advanced age.

Altogether, these data suggest that CML may not represent a particular vulnerability, although few exceptions may exist, such as blast crisis. Further case reports and longer follow up are needed to better ascertain independent risk factors, the impact of COVID-19, and the possible role that TKI type may play in this population.

1. Rea D, et al. COVID-19 in Patients (pts) with Chronic Myeloid Leukemia (CML): Results from the International CML Foundation (iCMLf) CML and COVID-19 (CANDID) Study. 62^nd ASH Annual Meeting, 5-8 December 2020. Abstract 649.
2. Lee LY, et al. Lancet. 2020;395:1919-26.

Posted on 18 February 202122 February 2021