Infections in relapsed myeloma patients treated with isatuximab plus pomalidomide and dexamethasone during the COVID-19 pandemic: Initial results of a UK-wide real-world study

OBJECTIVES

There are no real-world data describing infection morbidity in relapsed/refractory myeloma (RRMM) patients treated with anti-CD38 isatuximab in combination with pomalidomide and dexamethasone (IsaPomDex). In this UK-wide retrospective study, we set out to evaluate infections experienced by routine care patients who received this novel therapy across 24 cancer centres during the COVID-19 pandemic.

METHODS

The primary endpoint was infection morbidity (incidence, grading, hospitalization) as well as infection-related deaths. Secondary outcomes were clinical predictors of increased incidence of any grade (G2-5) and high grade (≥G3) infections.

RESULTS

In a total cohort of 107 patients who received a median (IQR) of 4 cycles (2-8), 23.4% of patients experienced ≥1 any grade (G2-5) infections (total of 31 episodes) and 18.7% of patients experienced ≥1 high grade (≥G3) infections (total of 22 episodes). Median time (IQR) from start of therapy to first episode was 29 days (16-75). Six patients experienced COVID-19 infection, of whom 5 were not vaccinated and 1 was fully vaccinated. The cumulative duration of infection-related hospitalizations was 159 days. The multivariate (MVA) Poisson Regression analysis demonstrated that a higher co-morbidity burden with Charlson Co-morbidity Index (CCI) score ≥4 (incidence rate ratio (IRR) = 3, p = 0.012) and sub-optimal myeloma response less than a partial response (<PR) (p = 0.048) are independent predictors of ≥ G3 infections.

CONCLUSION

Our study described initial results of infection burden during IsaPomDex treatment. We recommend close monitoring particularly in elderly patients with co-morbidities, the effective use of an-infective prophylaxis, as well as optimal vaccination strategies, to limit infections.

Diagnostic uncertainty presented barriers to the timely management of acute thrombotic thrombocytopenic purpura in the United Kingdom between 2014 and 2019

BACKGROUND

Acute thrombotic thrombocytopenic purpura (TTP) is a life-threatening emergency and plasma exchange (PEX) is the initial treatment shown to reduce acute mortality.

OBJECTIVES

To compare current practice in the United Kingdom (UK) against the standards set out in the 2012 British Society of Haematology guideline, and to better understand the issues affecting prompt initiation of PEX.

PATIENTS/METHODS

The trainee research network HaemSTAR conducted a retrospective nationwide review of adults presenting to UK hospitals with a first episode of acute TTP.

RESULTS

Data on 148 patients treated at 80 UK hospitals between 2014 and 2019 demonstrated that 64.8% of patients received PEX within 24 h. Diagnostic uncertainty was the most commonly cited reason for delayed treatment. Conversely, a shorter time to PEX occurred in patients who had red cell fragments or severe thrombocytopenia identified on their first complete blood count. Availability of on-site PEX was associated with a greater proportion of patients receiving PEX within 8 h compared to patients transferred, but by 24 h there was no difference between the two groups and two-thirds of all patients had received their first PEX. The mortality rate for patients that received PEX was 9.2%, with 27.8% of deaths linked to delayed treatment initiation.

CONCLUSIONS

This is the first multi-center evaluation of treatment delays in acute TTP and it will inform targeted pathways to improve prompt access to life-saving intervention.

Very early lineage-specific chimerism after reduced intensity stem cell transplantation is highly predictive of clinical outcome for patients with myeloid disease

BACKGROUND

The importance of chimerism status in the very early period after hematopoietic stem cell transplantation is unclear. We determined PBMC and T-cell donor chimerism 50 days after transplantation and related this to disease relapse and overall survival.

METHODS

144 sequential patients underwent transplantation of which 90 had AML/MDS and 54 had lymphoma. 'Full donor chimerism' was defined as ≥99% donor cells and three patient groups were defined: 40% with full donor chimerism (FC) in both PBMC and T-cells; 25% with mixed chimerism (MC) within both compartments and 35% with 'split' chimerism (SC) characterised by full donor chimerism within PBMC and mixed chimerism within T-cells.

RESULTS

In patients with myeloid disease a pattern of mixed chimerism (MC) was associated with a one year relapse rate of 45% and a five year overall survival of 40% compared to values of 8% and 75%, and 17% and 60%, for those with SC or FC respectively. The pattern of chimerism had no impact on clinical outcome for lymphoma.

CONCLUSION

The pattern of lineage-specific chimerism at 50 days after transplantation is highly predictive of clinical outcome for patients with myeloid malignancy and may help to guide subsequent clinical management.