Revisiting Cytomegalovirus Serology in Allogeneic Hematopoietic Cell Transplant Recipients.

BACKGROUND: Allogeneic hematopoietic cell transplant recipients (allo-HCTRs) with positive cytomegalovirus (CMV) serology may have false-positive results due to blood product transfusion-associated passive immunity. METHODS: This single-center cohort study included allo-HCTRs with negative baseline (at malignancy diagnosis) CMV serology and indeterminate/low-positive (CMV IgG titer, ≥0.6-<50 U/mL) pretransplant CMV serology with negative pretransplant plasma CMV DNAemia. The CMV status of those patients was reclassified from R+ to R- (CMVR- reclassification group). We compared those patients to allo-HCTRs with negative (CMV IgG titer <0.6 U/mL) pretransplant CMV IgG (CMVR- group). We describe the number and type of patients whose pretransplant CMV status was reclassified from indeterminate/positive to negative. We reviewed all plasma CMV DNAemia tests performed during the first 6 months posttransplant in both groups to assess the safety of this approach. RESULTS: Among 246 (84.5%) of 291 transplanted patients identified as CMVR+ pretransplant, 60 (24.4%) were reclassified from CMV serology indeterminate (N:10)/low-positive (N:50) to R-. Only 1 of 60 patients (1.67%) in the CMVR- reclassification group versus 3 of 44 (6.8%; P = .30) in the CMVR- group developed CMV DNAemia during the follow-up period. There were no significant differences in the number of CMV DNAemia tests performed, CMV DNAemia range, and time posttransplant between the 2 groups. CONCLUSIONS: One of 4 allo-HCT CMVR+ may be falsely flagged as R+, with significant impact on donor selection and prophylaxis administration. A 2-step approach including CMV serology testing at hematologic malignancy diagnosis in allo-HCT candidates and careful review of pretransplant CMV IgG titers may help correctly classify CMV serology status.

Hematopoietic cell transplantation and cellular therapies in Switzerland. Evolution over 25 years. A report from the stem cell transplantation and cellular therapies working groups of the SBST 1997-2021.

The Swiss Blood Stem Cell Transplantation and Cellular Therapy Group (SBST) leads a mandatory national registry for all hematopoietic stem cell transplants (HCT) and cellular therapies. After 25 years, information was available for 11,226 patients receiving an HCT (4031 allogeneic and 7195 autologous), including 925 pediatric patients. We compared patient characteristics and outcome by quinquennia 1997-2001, 2002-2006, 2007-2011, 2012-2016, and 2017-2021. There were numerous changes over time. Allogeneic transplant recipients became older (median age 33.7 vs. 54.3) and had more frequently unrelated donors and reduced intensity conditioning in later quinquennia. Similarly, age increased for recipients of autologous HCT (median 48.3 vs. 59.9). We did not see a significant drop in transplant activity during the SARS-CoV-2 pandemic. Analysis of outcome showed overall survival (relative risk (RR) of death 0.664 (0.529-0.832) and progression free survival (RR 0.708 (0.577-0.870) being improved over time comparing the latest to the first quinquennium adjusting for risk factors. Non-relapse mortality decreased in recipients of allogeneic HCT (RR: 0.371 (0.270-0.509)) over time but relapse risks did not. Outcome of autologous HCT improved as well across quinquennia, this improvement was mainly due to decreased relapse risks (RR 0.681 (0.597-0.777)), possibly related to maintenance treatment or rescue treatment for relapse mainly in myeloma patients. Cellular therapies other than allogeneic or autologous HCT, particularly chimeric antigen receptor T-cells (CAR-T) treatment have started to increase after 2019, year of approval of the first commercial CAR-T product in Switzerland. Data on chimeric antigen receptor T-cell treatment are too early for comparative analyses. Detailed analyses of changes over time are presented. This study includes all HCTs, and cellular therapies, data useful for quality assurance programs, health care cost estimation and benchmarking. Between 50% and 60% of patients are long-term survivors after both types of HCT, indicating growing populations of surviving patients requiring long-term care.

Salvage Treatment of Refractory HSV Oral Lesions with Pritelivir in Allogeneic Hematopoietic Cell Transplant Recipients.

We present two allogeneic hematopoietic cell transplantation recipients (HCTr) treated with pritelivir for acyclovir-resistant/refractory (r/r) HSV infection based on the expanded access program of the pritelivir manufacturer. Outpatient treatment with pritelivir was administered, with partial response by week 1 of treatment and complete response by week 4 of treatment in both patients. No adverse events were noted. Pritelivir appears to be an effective and safe option for the management of acyclovir-r/r HSV infections in highly immunocompromised patients in an outpatient setting.

Therapeutic Drug Monitoring of Orally Administered Letermovir Prophylaxis in Allogeneic Hematopoietic Stem Cell Transplant Recipients.

With balanced safety-efficacy profile, letermovir anti-cytomegalovirus (CMV) prophylaxis is used in hematopoietic stem cell transplant recipients (HSCTR). We assessed feasibility and usefulness of letermovir therapeutic drug monitoring (TDM) in HSCTR. We performed a prospective observational study on letermovir-TDM including 40 consecutive adult CMV-seropositive allogeneic-HSCTR who received orally (PO) administered letermovir. Minimal blood concentrations of letermovir (Ctrough) were measured on days 3 and 7 postletermovir initiation and weekly thereafter. Letermovir-Ctrough remained stable during the first 70 days post-HSCT at a median of 286 µg/L (interquartile range, 131 to 591 µg/L), with large interpatient/intrapatient variability. No associations between breakthrough clinically significant CMV infection or detectable CMV DNAemia and letermovir-Ctrough were observed. Patients with letermovir-associated adverse events had higher letermovir-Ctrough than patients without (400 versus 266 µg/L, P = 0.02). Letermovir-Ctrough was similar in patients with or without gastrointestinal symptoms (280 versus 300 µg/L, P = 0.49). Acute grade ≥2 GvHD was associated with higher letermovir-Ctrough (479 versus 248 µg/L, P = 0.001), including gastrointestinal GvHD (499 versus 263 µg/L, P = 0.004). Concomitantly administered posaconazole and cyclosporine were associated with higher letermovir-Ctrough (707 versus 259 µg/L, P < 0.001 and 437 versus 248 µg/L, P = 0.01, respectively). In multivariable analysis, both posaconazole (odds ratio [OR], 4.9; 95% confidence interval [CI], 2.4 to 9.7; P < 0.0001) and cyclosporine-adjusted letermovir dose at 240 mg daily (OR, 3.5; 95% CI, 1.4 to 9.0; P = 0.01) were independently associated with higher letermovir-Ctrough. In conclusion, administration of PO letermovir led to measurable and relatively stable letermovir-Ctrough, without noticeable associations with clinical efficacy. Letermovir exposure was not affected by gastrointestinal symptoms, but with posaconazole and cyclosporine administration. Associations between letermovir and concomitantly administered agents and adverse events warrant additional clinical studies.

Very severe immune thrombocytopenia following SARS-CoV-2 vaccination requiring splenectomy: a case report.

BACKGROUND: Some conventional vaccines have been recognized as a cause of secondary immune thrombocytopenia (ITP). According to recent publications, mRNA vaccines are probably associated with an increased risk of ITP. CASE PRESENTATION: Our patient developed severe ITP one week after the second dose of COVID-19 mRNA vaccine. Medical management was not effective, requiring splenectomy to obtain sustained remission. CONCLUSION: Considering the temporality and immunological hypothesis, we consider the vaccine to be the trigger of this ITP. To our knowledge, our case is, to date, the most severe case of ITP reported following SARS-CoV-2 vaccination and could help for the therapeutic management of similar patients.

When and how do we stop antifungal treatment for an invasive mould infection in allogeneic haematopoietic cell transplant recipients?

BACKGROUND: Limited data exist to describe end-of-treatment (EOT) parameters of antifungal therapy for invasive mould infections (IMI). METHODS: In a 10-year cohort of consecutive adult allogeneic haematopoietic cell transplant recipients with proven/probable IMI, we describe treatment duration and patient profile at EOT. RESULTS: There were 61 patients with 66 proven/probable IMI identified: 47/66 (71%) invasive aspergillosis (IA), 11/66 (17%) mucormycosis, and 8/66 (12%) other-IMI. Excluding 5 (8%) patients lost to follow-up, treatment was prematurely discontinued due to death or palliative care in 29/56 (51.8%) patients. Antifungal treatment was completed in 27 (48.2%) patients, for a median duration of 280 days (IQR: 110, 809): 258 (IQR: 110, 1905) and 307.5 (99, 809) days in IA and non-IA IMI, respectively. Treatment was continued after 90 and 180 days in 43/56 (76.8%) and 30/56 (53.6%) patients, respectively. At EOT, most patients were not neutropenic (ANC: 2.12 G/L, IQR: 0.04, 5.3), with CD4+ counts at 99 cells/µl (IQR: 0, 759) and immunoglobulins at 5.6 g/L (IQR: 2.3, 10.6). Most patients (16/27, 59.3%) were not receiving steroids at EOT, while 14/27 (53.9%) were on another type of immunosuppression. Amongst 15 patients with imaging at EOT, 12 (80%) had complete/partial radiologic response. Any chart documentation or an infectious disease consultation on treatment discontinuation was observed in 12/56 (21%) and 11/56 (20%) patients, respectively. CONCLUSIONS: Long treatment courses are observed in patients with IMI, due to prolonged immunosuppression. Although immune reconstitution and radiological response were frequently observed at EOT, consistent documentation of treatment discontinuation based on well-defined parameters is lacking.

Frequency and causes of antifungal treatment changes in allogeneic haematopoïetic cell transplant recipients with invasive mould infections.

BACKGROUND: Antifungal treatment duration and changes for invasive mould infections (IMI) have been poorly described. METHODS: We performed a 10-year cohort study of adult (≥18-year-old) allogeneic haematopoietic cell transplant recipients with proven/probable IMI to describe the duration and changes of antifungal treatment. All-cause-12-week mortality was described. RESULTS: Sixty-one patients with 66 IMI were identified. Overall treatment duration was 157 days (IQR: 14-675) and 213 (IQR: 90-675) days for patients still alive by Day 84 post-IMI diagnosis. There was at least one treatment change in 57/66 (86.4%) cases: median 2, (IQR: 0-6, range:0-8). There were 179 antifungal treatment changes due to 193 reasons: clinical efficacy (104/193, 53.9%), toxicity (55/193, 28.5%), toxicity or drug interactions resolution (15/193, 7.8%) and logistical reasons (11/193, 5.7%) and 15/193 (7.8%) changes due to unknown reasons. Clinical efficacy reasons included lack of improvement (34/104, 32.7%), targeted treatment (30/104, 28.8%), subtherapeutic drug levels (14/104, 13.5%) and other (26/104, 25%). Toxicity reasons included hepatotoxicity, nephrotoxicity, drug interactions, neurotoxicity and other in 24 (43.6%), 12 (21.8%), 12 (21.8%), 4 (7.4%) and 3 (5.5%) cases respectively. All-cause 12-week mortality was 31% (19/61), higher in patients whose antifungal treatment (logrank 0.04) or appropriate antifungal treatment (logrank 0.01) was started >7 days post-IMI diagnosis. All-cause 1-year mortality was higher in patients with ≥2 changes of treatment during the first 6 weeks post-IMI diagnosis (logrank 0.008) with an OR: 4.00 (p = .04). CONCLUSIONS: Patients with IMI require long treatment courses with multiple changes for variable reasons and potential effects on clinical outcomes, demonstrating the need more effective and safer treatment options. Early initiation of appropriate antifungal treatment is associated with improved outcomes.

Clinical and Pharmacological Considerations for Concomitant Administration of Posaconazole and Isavuconazole with Letermovir.

We sought in this case-control retrospective study to compare posaconazole and isavuconazole (PCZ and IVC, respectively) plasma trough concentration (Ctrough) levels in high-risk allogeneic hematopoietic cell transplant (HCT) recipients who received letermovir (LET) or not. PCZ/IVC Ctrough levels were not found to be significantly different between cases and controls, as they were 1.31 mg/liter (median) (interquartile range [IQR], 0.90) versus 1.36 mg/liter (IQR, 1.16) (P = 0.31) and 3.20 mg/liter (IQR, 2.40) versus 2.35 mg/liter (IQR, 1.50) (P = 0.17), respectively. In conclusion, we observed PCZ/IVC Ctrough levels within the expected range and no significant effect of LET coadministration.

Clinical considerations on posaconazole administration and therapeutic drug monitoring in allogeneic hematopoietic cell transplant recipients.

There is a paucity of data on posaconazole (PCZ) dosing and therapeutic-drug-monitoring (TDM) in allogeneic hematopoietic cell transplant recipients (allogeneic-HCTr). This was a 3-year retrospective multicenter study (January 1, 2016 to December 31, 2018) in adult allogeneic-HCTr who received PCZ (intravenously, IV and/or as delayed-release tablet, DRT) as prophylaxis or treatment for ≥7 consecutive days (D) with at least 1-PCZ-level available using data of the Swiss Transplant Cohort Study. The primary objective was to describe the distribution of PCZ-level and identify predictors of therapeutic PCZ-level and associations between PCZ-dosing and PCZ-level. A total of 288 patients were included: 194 (67.4%) and 94 (32.6%) received PCZ as prophylaxis and treatment, respectively, for a median of 90 days (interquartile range, IQR: 42-188.5). There were 1944 PCZ-level measurements performed, with a median PCZ level of 1.3 mg/L (IQR: 0.8-1.96). PCZ-level was <0.7 mg/L in 383/1944 (19.7%) and <1.0 mg/L in 656/1944 (33.7%) samples. PCZ-level was <0.7 mg/L in 260/1317 (19.7%) and <1.0 mg/L in 197/627 (31.4%) in patients who received PCZ-prophylaxis versus treatment, respectively. There were no significant differences in liver function tests between baseline and end-of-treatment. There were nine (3.1%) breakthrough invasive fungal infections (bIFI), with no difference in PCZ levels between patients with or without bIFI. Despite a very intensive PCZ-TDM, PCZ-levels remain below target levels in up to one-third of allogeneic-HCTr. Considering the low incidence of bIFI observed among patients with PCZ levels in the targeted range, our data challenge the clinical utility of routine universal PCZ-TDM.

Clinical Considerations of Isavuconazole Administration in High-Risk Hematological Patients: A Single-Center 5-Year Experience.

BACKGROUND: There are limited real-life data on isavuconazole prophylaxis and treatment of invasive mold infections (IMI) in hematological patients and allogeneic hematopoietic cell transplant (HCT) recipients. OBJECTIVES: Primary objective was to describe the indications of real-life isavuconazole administration at a university hospital. Secondary objectives included the description of liver function tests and QTc interval between baseline and end of treatment (EOT), clinical outcomes and breakthrough IMI by the EOT. PATIENTS/METHODS: This was a 5-year single-center retrospective study of all adult patients with acute myeloid leukemia and/or allogeneic HCT recipients who received isavuconazole as prophylaxis and/or treatment between June 1, 2016, and July 31, 2020. RESULTS: Among 30 identified patients, the indications for isavuconazole administration were adverse events associated with prior antifungal treatment (N: 18, 60%: hepatotoxicity, renal insufficiency, long QTc interval, neurotoxicity, and potential drug-drug interactions in 6, 4, 3, 1 and 4 patients, respectively), clinical efficacy (N: 5, 16.6%), and other reasons (N: 10, 33.3%; 5/10 patients treated with isavuconazole to facilitate hospital discharge with orally administered appropriate treatment). Alanine aminotransferase significantly decreased from baseline (mean: 129 IU/L, range: 73, 202) to a mean of 48 IU/L (range: 20, 80) by day 14 (P-value: 0.02), 23.5 IU/L (range: 20, 27) by day 28 (P-value: 0.03) and 16.5 IU/L (range: 16, 17) by day 42 (P-value: 0.009). The QTc interval decreased from baseline (mean: 456.8 ms, range: 390, 533) to EOT (mean: 433.8 ms, range: 400, 472; P-value: 0.03). The mean isavuconazole plasma concentration was 2.9 mg/L (range: 0.9, 6.7). There was no breakthrough IMI observed. CONCLUSION: Isavuconazole is a safe and reliable antifungal agent in complex hematological patients, with relatively low hepatotoxicity and QTc interval shortening properties.

Microbiologically documented infections after adult allogeneic hematopoietic cell transplantation: A 5-year analysis within the Swiss Transplant Cohort study.

BACKGROUND: Infections are an important complication after allogeneic hematopoietic cell transplantation (allo-HCT). The present study aimed at determining the landscape of infections occurring in a large cohort of allo-HCT patients, as well as associated risk factors for infections and for one-year non-relapse mortality. METHODS: This is a retrospective cohort study using STCS and EBMT databases to assess the one-year incidence rate of infection, as well as risk factors for infections and for one-year non-relapse mortality among adult allo-HCT patients transplanted between 2010 and 2014 in Switzerland. Univariable and multivariable quasi-Poisson and multivariable Cox regression models were used. RESULTS: Of 553 patients included, 486 had an infection with a global incidence rate of 3.66 infections per patient-year. Among a total of 1534 infections analyzed, viral infections were predominant (n = 1138, 74.2%), followed by bacterial (n = 343, 22.4%) and fungal (n = 53, 3.5%) infections. At one year, the cumulative incidence of relapse and non-relapse mortality was 26% and 16%, respectively. 195 (35.3%) of patients had at least one episode of severe graft-versus-host-disease (GvHD). A center effect was observed, and underlying disease, donor type, cytomegalovirus serological constellation, and GvHD were also associated with the incidence rate of infections. There was an increased risk for one-year non-relapse mortality associated with all pathogens, specifically within two months of infection, and this remained true beyond 2 months of a fungal infection. CONCLUSION: Despite advances to limit infections in this population, they still occur in most allo-HCT patients with a major impact on survival at 1 year.

Compartmentalization of a Multidrug-Resistant Cytomegalovirus UL54 Mutant in a Stem Cell Transplant Recipient with Encephalitis.

We report a case of cytomegalovirus encephalitis in a hematopoietic stem cell transplant recipient. A previously uncharacterized V787E mutation in UL54 was identified in cerebrospinal fluid but not plasma specimens. For the V787E recombinant virus, the half maximal effective concentrations for ganciclovir, foscarnet, and cidofovir were 8.6-, 3.4- and 2.9-fold higher than for wild-type virus, and the replicative capacity was lower. The introduction of a bulkier and negatively charged glutamate residue at position 787 could destabilize the finger domain of UL54 DNA polymerase. Viral genotyping of cerebrospinal fluid is warranted in subjects with cytomegalovirus encephalitis, owing to the low penetration of antivirals in this compartment.

Burden of severe RSV disease among immunocompromised children and adults: a 10 year retrospective study.

BACKGROUND: Respiratory syncytial virus (RSV) is associated with significant mortality rates amongst hematopoietic stem cell transplant (HSCT) recipients, with less known about other immunocompromised patients. METHODS: Ten-year retrospective cohort study of immunocompromised patients presenting with RSV disease documented at University Hospitals of Lausanne and Geneva. Severe RSV-related outcomes referred to RSV documented respiratory conditions requiring hospital admission, presenting as lower respiratory tract infection (LRTI) or pneumonia. We used multivariable logistic regression to assess clinical and laboratory correlates of severe RSV disease. RESULTS: From 239 RSV-positive immunocompromised in and out-patients 175 were adults and 64 children of whom 111 (47.8%) presented with LRTI, which resulted in a 38% (89/239) admission rate to hospital. While immunocompromised children were more likely to be admitted to hospital compared to adults (75% vs 62.9%, p = 0.090), inpatients admitted to the intensive care unit (17/19) or those who died (11/11) were mainly adults. From multivariable analyses, adults with solid tumors (OR 5.2; 95% CI: 1.4-20.9 P = 0.015) or those requiring chronic immunosuppressive treatments mainly for rheumatologic conditions (OR 4.1; 95% CI: 1.1-16.0; P = 0.034) were significantly more likely to be admitted to hospital compared to hematopoietic stem cell (HSCT) recipients. Bacterial co-infection was significantly and consistently associated with viral LRTI and pneumonia. CONCLUSIONS: From our findings, RSV-related disease results in a significant burden among adults requiring chronic immunosuppressive treatments for rheumatological conditions and those with solid tumors. As such, systematic screening for respiratory viruses, should be extended to other immunocompromised populations than HSCT recipients.

NK Cell Functional Impairment after Allogeneic Hematopoietic Stem Cell Transplantation Is Associated with Reduced Levels of T-bet and Eomesodermin.

NK cells play a major role in protection against tumor recurrence and infection after allogeneic hematopoietic stem cell transplantation (HSCT). It has been shown that NK cell function after HSCT is impaired, but underlying molecular mechanisms are not well-known. In this report we show that the level of T-bet and Eomesodermin (Eomes), two T-box transcription factors regulating lymphocyte effector functions, is strongly reduced in NK cells from HSCT recipients compared with healthy control subjects. Reduction of T-bet and Eomes expression appeared early and persisted for years after HSCT, affecting all peripheral blood NK cells independently of their differentiation status. Reduced T-bet levels in NK cells from allogeneic HSCT recipients significantly correlated with reduced perforin expression. Acute, but not chronic, graft-versus-host disease, as well as CMV reactivation, was associated with further downregulation of T-bet expression in NK cells. Lower levels of T-bet expression in NK cells were associated with less favorable outcome after HSCT as a result of increased nonrelapse mortality. Collectively, our results provide a possible molecular explanation for the previously reported functional exhaustion of NK cells after allogeneic HSCT and suggest an impact of the NK transcriptional machinery status on HSCT outcome.

Validation of the disease risk index for outcome of patients undergoing allogeneic hematopoietic stem cell transplantation after T cell depletion.

Identification of pretransplantation risk factors is important in evaluating patient outcomes after hematopoietic stem cell transplantation. Current scoring schemes, such as the European Group for Blood and Marrow Transplantation risk score or the Hematopoietic Cell Transplantation-Specific Comorbidity Index, may under-rate disease and disease status at the time of transplantation. The recently published Disease Risk Index (DRI) specifically investigates these aspects by defining 4 risk groups (low, intermediate, high, very high) with significant differences in overall survival (OS). We retrospectively investigated whether the DRI could be applied at the transplantation center of Geneva's University Hospitals (Geneva, Switzerland), where 64% of patients are underwent transplantation with T cell-depleted grafts (TDEP). We analyzed 409 patients with various hematological malignancies who underwent transplantation between January 1998 and October 2012. Using the DRI, the 4-year OS for the low, intermediate, high, and very high groups was 82%, 53%, 27%, and 31%, respectively (P < .0001). For TDEP patients, the 4-year OS for low, intermediate, and high overall risk groups was 86%, 53%, and 33%, respectively (P < .0001). As patients in the very high overall risk group are usually not eligible for TDEP, our group comprised too few patients (n = 3) for meaningful analysis. For non-TDEP patients, the 4-year OS for low, intermediate, high, and very high overall risk groups was 63%, 54%, 22%, and 18%, respectively (P < .0001). Our results confirm the prognostic value of the DRI in a cohort with a majority of TDEP patients.

Severe anaphylaxis after chimeric antigen receptor T-cell injection: a case report.

Anaphylactic reactions at the time of chimeric antigen receptor T (CAR-T) cell infusion are adverse events that have not been reported in pivotal clinical trials or in real-world series. We report the case of patient with severe anaphylaxis with cardiac arrest after tisagenlecleucel injection for Diffuse Large B cell Lymphoma, who recovered after resuscitation and intensive care treatment; we also conducted a Food and Drug Administration Adverse Event Reporting System database analysis and found several cases of severe anaphlyaxis after CAR-T cell injection. Although not reported in pivotal CAR-T cell studies, anaphylaxis can occur after CAR-T cell injection, highlighting the need to include anaphylaxis as a possible side effect in future studies.

[Second allogeneic (update). Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Deuxième allogreffe (mise à jour). Recommandations de la Société francophone de greffe de moelle osseuse et de thérapie cellulaire (SFGM-TC).

Relapse after allogeneic hematopoietic cell transplantation (allo-HCT) remains a major concern because it is associated with poor survival. A second allo-HCT is a valid option in this situation. During the 13th annual harmonization workshops of the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC), a designated working group reviewed the literature in order to update the second allo-HCT recommendations elaborated during the previous workshop (2016). The main indication for a second allo-HCT remains relapse of initial hematologic malignancy. Disease status; complete remission (CR), and relapse time after the first allo-HCT>6 months impact positively the overall survival of patients after the second allo-HCT. Donor change is a valid option, particularly if there is HLA loss on leukemic cells after a first haploidentical or following a mismatched allo-HCT is documented. Reduced intensity conditioning is recommended, while a sequential protocol is a reasonable option in patients with proliferative disease. A post-transplant maintenance strategy after hematological recovery is recommended as soon as day 60, even if the immunosuppressive treatment has not yet been stopped. Hypomethylating agents, and targeted therapies such as anti FLT3, anti BCL2, anti-IDH1/2, TKI, anti-TP53, anti-CD33, anti-CD19, anti-CD22, anti-CD30, check point inhibitors, and CAR-T cells can be used as a bridge to transplant or as an alternative treatment to the second allo-HCT.

Remission of relapsed/refractory classical Hodgkin lymphoma induced by brentuximab vedotin and pembrolizumab combination after allogeneic hematopoietic stem cell transplantation: a case report.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with highly chemorefractory Hodgkin lymphoma (HL). The CD30-targeting antibody-drug conjugate Brentuximab-Vedotin (BV) and programmed cell death protein-1 (PD-1) blocking agents have demonstrated clinical activity with durable responses in relapsed/refractory (r/r) HL. However, patients with a history of allo-HSCT were frequently excluded from clinical trials due to concerns about the risk of graft-versus-host disease (GVHD). We report the clinical history of a patient with refractory classical HL who underwent two allo-HSCTs (first from matched unrelated and second from haploidentical donor) after relapsing on BV and nivolumab and for whom durable remission was finally obtained using BV-pembrolizumab combination for relapse after haploidentical HSCT. Such treatment was associated with the onset of GVHD after only two cycles which led to treatment discontinuation. However, the side effects were rapidly controlled, and after 2 years of follow-up, the patient is still in remission. Our data support the feasibility and efficacy of combining PD-1 blockade with BV to enhance the graft-versus-lymphoma effect after allo-HSCT.

Allogeneic haematopoietic cell transplantation for chronic myeloid leukaemia in Switzerland in the face of rapid development of effective drugs.

AIM: Until the year 2000, allogeneic haematopoietic cell transplantation (HCT) was the standard treatment for young and fit chronic myeloid leukaemia (CML) patients. CML was the main indication for allogeneic HCT. The introduction of tyrosine kinase inhibitors changed the treatment of CML patients dramatically. Allogeneic HCT was rapidly replaced by tyrosine kinase inhibitors as first-line treatment for CML, and the indication shifted to the treatment of non-responders, patients intolerant to tyrosine kinase inhibitors and patients whose CML is transforming to the accelerated phase and blast crisis. This paper describes changes in the use of transplantation technology for CML patients in the face of rapid drug development. METHODS: All patients receiving a transplant for CML between 1997 and 2021 in Switzerland were included in the study. For the purpose of this analysis, time periods were analysed in quinquennia, 1997-2001 (Q1), 2002-2006 (Q2), 2007-2011 (Q3), 2012-2016 (Q4) and 2017-2021 (Q5), as the observation period spanned 25 years. RESULTS: Overall, 239 patients received a transplant. These included 96 in Q1, 56 in Q2, 25 in Q3, 34 in Q4 and 28 in Q5. Patient characteristics changed over time: recent patients were older and had a longer interval from diagnosis to transplantation because of tyrosine kinase inhibitor treatment. However, the proportions of patients receiving transplants during an early versus advanced disease stage differed little. Transplant technology changed, as well. Patients received intensive conditioning regimens less often due to higher age and more commonly had peripheral blood as opposed to bone marrow transplants. However, the type of stem cell donor selected did not differ. In a univariable analysis, there were no significant differences in survival, progression-free survival, non-relapse mortality, relapse incidence or incidences of acute and chronic graft-versus-host disease among the five quinquennia. In a multivariable analysis, older age, donors other than HLA-identical siblings and more advanced disease stage, but not the quinquennium, were associated with higher risk of death. CONCLUSION: Since the introduction of tyrosine kinase inhibitors haematopoietic cell transplantation has been used less frequently to treat CML. Patients in recent cohorts received transplants at an older age and later in the disease course; despite these higher risks, the outcome of allogeneic HCT has not worsened over time but has not improved, either. As the outcome is worse in advanced phases, it is important to conduct transplants before disease progression. Therefore, patients with advanced disease should be monitored closely and receive transplants in time.