According to the consensus statement of the European Myeloma Network,1 “patients with multiple myeloma (MM) seem to be at increased risk for more severe COVID-19 and associated complications due to their immunocompromised state, the older age, and comorbidities.” We present a case of a patient with 3 different cancers who was diagnosed with SARS-CoV-2 infection and spontaneously eliminated it during current treatment.

A 63-year-old woman was diagnosed with left breast cancer stage IIA (T2 N0 M0) in 2008. In 2019, chondrosarcoma grade 1 was found in Th12 vertebra (Figure 1). She developed acute renal failure (creatinine, 7.8 mg/dl; estimated glomerular filtration rate, 6 ml/min/1.73 m2) due to light chain disease lambda III B stage III according to the International Staging System for Multiple Myeloma. Remission-inducing chemotherapy according to the VTD protocol (bortezomib, thalidomide, dexamethasone) was started. In April 2020, a consecutive dose of bortezomib was administrated just prior to a routine control test for SARS-CoV-2 (a reverse transcriptase–polymerase chain reaction 2-gene test) which yielded a positive result. The patient was asymptomatic, in good general condition, and self-isolated at home. Control tests for SARS-CoV-2 performed 2 weeks later were negative; she did not develop any SARS-CoV-2 antibodies.

Figure 1. A – computed tomography of the whole body (polytrauma protocol) performed in December 2019, showing a history of a burst fracture of the T12 vertebral body in the course of chondrosarcoma; the lesions were not radically removed. Posterior stabilization of the spine with stabilizing rods and transpedicular screws (arrow), wedge-shaped decrease at the height of the T5 and T7 vertebral bodies (as a result of fractures) as well as numerous osteolytic lesions due to multiple myeloma are visible. B – computed tomography of the head (transverse plane) visualizing numerous osteolytic lesions of various sizes in the bones of the skull; the largest lesion (29 × 9 mm) is localized in the occipital bone (arrow)

The patient continues to receive remission-inducing treatment and dialysis. Selected results of laboratory test performed at the times of MM and SARS-CoV-2 infection diagnosis are presented in Supplementary material, Table S1.

Hereby we report a case of a patient with 3 different malignancies: breast cancer diagnosed several years ago, followed by recently found chondrosarcoma and MM. She was treated with bortezomib, thalidomide, and dexamethasone when asymptomatic SARS-CoV-2 infection was diagnosed. In such scenario, a severe course of COVID-19 would be expected because of profound immunosuppression; in fact, the infection was asymptomatic and disappeared quickly.

The role of Bruton tyrosine kinase inhibitors in the therapy of COVID-19 has been previously discussed. They can be effective in the treatment of COVID-19 due to their anti-inflammatory and antiviral activity. Bruton tyrosine kinase is involved in sustained inflammation through nuclear factor–kappa B (NF-κB) activation, production of proinflammatory cytokines, and cellular senescence, leading to organ damage and spread of viral particles.2

Our patient received bortezomib, which inhibits the NF-κB/IκB transcription factor. Activation of the NF-κB pathway by coronaviruses can increase viral replication and lead to hyperactivation of immune mechanisms such as cytokine storm in SARS-CoV-2 infection.3 Inhibitors of NF-κB improved survival among mice infected with SARS-CoV, which is similar to SARS-CoV-2 in terms of reducing the amount of proinflammatory proteins.4 Suppression of NF-κB may enhance interferon-mediated antiviral activity and improve the disease outcome.2-4 It means that both mechanisms connected with NF-κB can be involved in the therapy with bortezomib in patients with MM and SARS-CoV-2 infection.

In the RECOVERY trial, dexamethasone was the most effective drug among critically ill COVID-19 patients, but not in less severe cases.5 Nevertheless, its anti-inflammatory effect in our patient cannot be excluded.

Although our conclusions may be controversial, we cannot exclude the possibility that the use of bortezomib with dexamethasone in a patient with MM was the reason for the mild course of SARS-CoV-2 infection due to its anti-inflammatory and probably antiviral effect. To our best knowledge, this is the first report suggesting the efficacy of treatment with bortezomib in coronavirus infection.