Impaired T and "memory-like" NK-cell reconstitution is linked to late-onset HCMV reactivation after letermovir cessation.

Allogeneic hematopoietic stem cell transplantation (alloSCT) is the only cure for many hematologic malignancies. However, alloSCT recipients are susceptible to opportunistic pathogens such as human cytomegalovirus (HCMV). Letermovir prophylaxis has revolutionized HCMV management, but the challenge of late HCMV reactivations has emerged. Immunological surrogates of clinically significant HCMV reactivations (csCMVi) after discontinuation of letermovir remain to be defined. Therefore, we studied NK-cell reconstitution along with the global and HCMV pp65-specific T-cell repertoire of 24 alloSCT recipients at seven timepoints before (day +90) and after (days +120-270) cessation of letermovir prophylaxis. Patients who experienced csCMVi had lower counts of IFNγ+ HCMV-specific CD4+ and CD8+ T cells than HCMV controllers. Furthermore, csCMVi patients displayed late impairment of NK-cell reconstitution, especially suppression of "memory-like" CD159c+CD56dim NK-cell counts that preceded csCMVi events in most patients. Moreover, several surrogates of immune reconstitution were associated with the severity of HCMV manifestation, with patients suffering from HCMV end-organ disease and/or refractory HCMV infection harboring least HCMV-specific T cells and "memory-like" NK cells. Altogether, our findings establish an association of delayed or insufficient proliferation of both HCMV-specific T cells and "memory-like" NK cells with csCMVi and the severity of HCMV manifestations following discontinuation of letermovir prophylaxis.

CD4+ T cells are the major predictor of HCMV control in allogeneic stem cell transplant recipients on letermovir prophylaxis.

Introduction: Human cytomegalovirus (HCMV) causes significant morbidity and mortality in allogeneic stem cell transplant (alloSCT) recipients. Recently, antiviral letermovir prophylaxis during the first 100 days after alloSCT replaced PCR-guided preemptive therapy as the primary standard of care for HCMV reactivations. Here, we compared NK-cell and T-cell reconstitution in alloSCT recipients receiving preemptive therapy or letermovir prophylaxis in order to identify potential biomarkers predicting prolonged and symptomatic HCMV reactivation. Methods: To that end, the NK-cell and T-cell repertoire of alloSCT recipients managed with preemptive therapy (n=32) or letermovir prophylaxis (n=24) was characterized by flow cytometry on days +30, +60, +90 and +120 after alloSCT. Additionally, background-corrected HCMV-specific T-helper (CD4+IFNγ+) and cytotoxic (CD8+IFNγ+CD107a+) T cells were quantified after pp65 stimulation. Results: Compared to preemptive therapy, letermovir prophylaxis prevented HCMV reactivation and decreased HCMV peak viral loads until days +120 and +365. Letermovir prophylaxis resulted in decreased T-cell numbers but increased NK-cell numbers. Interestingly, despite the inhibition of HCMV, we found high numbers of "memory-like" (CD56dimFcεRIγ- and/or CD159c+) NK cells and an expansion of HCMV-specific CD4+ and CD8+ T cells in letermovir recipients. We further compared immunological readouts in patients on letermovir prophylaxis with non/short-term HCMV reactivation (NSTR) and prolonged/symptomatic HCMV reactivation (long-term HCMV reactivation, LTR). Median HCMV-specific CD4+ T-cell frequencies were significantly higher in NSTR patients (day +60, 0.35 % vs. 0.00 % CD4+IFNγ+/CD4+ cells, p=0.018) than in patients with LTR, whereas patients with LTR had significantly higher median regulatory T-cell (Treg) frequencies (day +90, 2.2 % vs. 6.2 % CD4+CD25+CD127dim/CD4+ cells, p=0.019). ROC analysis confirmed low HCMV specific CD4+ (AUC on day +60: 0.813, p=0.019) and high Treg frequencies (AUC on day +90: 0.847, p=0.021) as significant predictors of prolonged and symptomatic HCMV reactivation. Discussion: Taken together, letermovir prophylaxis delays HCMV reactivation and alters NK- and T-cell reconstitution. High numbers of HCMV-specific CD4+ T cells and low numbers of Tregs seem to be pivotal to suppress post-alloSCT HCMV reactivation during letermovir prophylaxis. Administration of more advanced immunoassays that include Treg signature cytokines might contribute to the identification of patients at high-risk for long-term and symptomatic HCMV reactivation who might benefit from prolonged administration of letermovir.

Reliable and Interpretable Mortality Prediction With Strong Foresight in COVID-19 Patients: An International Study From China and Germany.

Cohort-independent robust mortality prediction model in patients with COVID-19 infection is not yet established. To build up a reliable, interpretable mortality prediction model with strong foresight, we have performed an international, bi-institutional study from China (Wuhan cohort, collected from January to March) and Germany (Würzburg cohort, collected from March to September). A Random Forest-based machine learning approach was applied to 1,352 patients from the Wuhan cohort, generating a mortality prediction model based on their clinical features. The results showed that five clinical features at admission, including lymphocyte (%), neutrophil count, C-reactive protein, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase, could be used for mortality prediction of COVID-19 patients with more than 91% accuracy and 99% AUC. Additionally, the time-series analysis revealed that the predictive model based on these clinical features is very robust over time when patients are in the hospital, indicating the strong association of these five clinical features with the progression of treatment as well. Moreover, for different preexisting diseases, this model also demonstrated high predictive power. Finally, the mortality prediction model has been applied to the independent Würzburg cohort, resulting in high prediction accuracy (with above 90% accuracy and 85% AUC) as well, indicating the robustness of the model in different cohorts. In summary, this study has established the mortality prediction model that allowed early classification of COVID-19 patients, not only at admission but also along the treatment timeline, not only cohort-independent but also highly interpretable. This model represents a valuable tool for triaging and optimizing the resources in COVID-19 patients.

Multiagent therapy with pomalidomide, bortezomib, doxorubicin, dexamethasone, and daratumumab ("Pom-PAD-Dara") in relapsed/refractory multiple myeloma.

BACKGROUND: Even in the era of novel immunotherapies for multiple myeloma (MM), treatment of late-stage relapsed/refractory (RR) patients remains challenging. The aim of our study was to analyze the efficacy and safety of the five-drug combination pomalidomide, bortezomib, doxorubicin, dexamethasone, and daratumumab ("Pom-PAD-Dara") in RRMM. METHODS: We retrospectively analyzed data of 56 patients with RRMM who received Pom-PAD-Dara between September 2016 and May 2019. RESULTS: Patients were heavily pretreated with a median of four prior lines of therapy, including autologous and allogenic stem cell transplant in 50 (89%) and six (11%) patients, respectively. The overall response rate (ORR) was 78% and we observed partial remission, very good partial remission, and complete remission in 27 (48%), 13 (23%) and four (7%) patients, respectively. Median progression-free survival was 7 months (95% CI, 3.3-10.7) and the median overall survival was not reached at 24 months. Adverse events grade ≥ 3 were observed 41 (73%) patients and included neutropenia (n = 28, 50%), anemia (n = 22, 39%), thrombocytopenia (n = 21, 38%), and pneumonia (n = 6, 11%). CONCLUSION: Pom-PAD-Dara represents a promising multiagent regimen in heavily pretreated RRMM patients with high ORR and an acceptable safety profile.

Obinutuzumab and venetoclax induced complete remission in a patient with ibrutinib-resistant non-nodal leukemic mantle cell lymphoma.

We herein report the case of a 73-year-old male patient who was diagnosed with leukemic non-nodal MCL. This patient had received six cycles of bendamustine, which resulted in a transient remission, and a second-line therapy with ibrutinib, which unfortunately failed to induce remission. We started a treatment with single-agent obinutuzumab at a dose of 20 mg on day 1, 50 mg on day 2-4, 330 mg on day 5, and 1000 mg on day 6. The laboratory analysis showed a rapid decrease of leukocyte count. Four weeks later, we repeated the treatment with obinutuzumab at a dose of 1000 mg q4w and started a therapy with venetoclax at a dose of 400 mg qd, which could be increased to 800 mg qd from the third cycle. This combination therapy was well tolerated. The patient achieved a complete remission (CR) after three cycles of obinutuzumab and venetoclax. To date, the patient has a progression-free survival of 17 months under ongoing obinutuzumab maintenance q4w. This is the first report about obinutuzumab and venetoclax induced CR in rituximab-intolerant patient with an ibrutinib-resistant MCL. This case suggests that obinutuzumab- and venetoclax-based combination therapy might be salvage therapy in patients with ibrutinib-resistant MCL.