Epitranscriptomics modifier pentostatin indirectly triggers Toll-like receptor 3 and can enhance immune infiltration in tumors.

The adenosine deaminase inhibitor 2'-deoxycoformycin (pentostatin, Nipent) has been used since 1982 to treat leukemia and lymphoma, but its mode of action is still unknown. Pentostatin was reported to decrease methylation of cellular RNA. We discovered that RNA extracted from pentostatin-treated cells or mice has enhanced immunostimulating capacities. Accordingly, we demonstrated in mice that the anticancer activity of pentostatin required Toll-like receptor 3, the type I interferon receptor, and T cells. Upon systemic administration of pentostatin, type I interferon is produced locally in tumors, resulting in immune cell infiltration. We combined pentostatin with immune checkpoint inhibitors and observed synergistic anti-cancer activities. Our work identifies pentostatin as a new class of an anticancer immunostimulating drug that activates innate immunity within tumor tissues and synergizes with systemic T cell therapies.

[Hairy cell leukemia: What are the best treatment options for relapsed or refractory patients?] / Leucémie à tricholeucocytes : quelles sont les meilleures options thérapeutiques pour les patients en rechute ou réfractaires ?

Hairy cell leukemia is a rare form of leukemia: three hundred new cases are diagnosed each year in France. The diagnosis is based on: (1) morphological examination of the blood and bone marrow smear, (2) analysis by flow cytometry of hairy cells, which express three or the four following markers: CD11c, CD25, CD103 and CD123, (3) identification of the BRAFV600E mutation, a true molecular marker of the disease. The management of treatment has evolved considerably in recent years. As of today, the purine analogues remain the standard treatment in the first line. Relapses are however observed in about 40% of cases. In the event of a first relapse, the preferred option is treatment with immunochemotherapy i.e. a combination of cladribine plus rituximab. Subsequent relapses are treated with moxetumomab pasudotox or BRAF inhibitors which provide indisputable benefits if third-line treatment is required. We will discuss in patients with relapsed/refractory hairy cell leukemia the needs for personalized medicine and the advantages and disadvantages of each treatment modality. The good prognosis for LT requires treatments that are not immunosuppressive, non-myelotoxic, and do not increase the risk of secondary cancers.

Clinical outcomes in T-cell large granular lymphocytic leukaemia: prognostic factors and treatment response.

T-cell large granular lymphocytic leukaemia (T-LGLL) is an incurable leukaemia characterised by clonal proliferation of abnormal cytotoxic T cells that can result in severe neutropenia, transfusion-dependent anaemia and pancytopenia requiring treatment. The most commonly used agents, methotrexate (MTX), cyclophosphamide (Cy) and cyclosporine primarily produce partial remissions (PRs), with few complete responses (CRs). We evaluated the clinical course and treatment response of 60 consecutive patients with T-LGLL to evaluate clinical outcomes and future potential treatment directions. Impaired overall survival was noted among male patients, patients with elevated lactate dehydrogenase, and those without rheumatoid arthritis. Cy was the most efficacious second-line agent, with a 70% overall response rate (ORR; three CR, four PR). All patients who failed frontline MTX responded to second-line Cy. In the relapsed or Cy-refractory setting, alemtuzumab (n = 4) and pentostatin (n = 3) had an ORR of 50% and 66%, respectively, while duvelisib induced a long-term response in one patient. In this large, retrospective analysis, our results suggest Cy is a highly effective therapy for second-line treatment in T-LGLL and should be considered a strong candidate for up-front therapy in select high-risk patients. Prospective studies evaluating pentostatin, alemtuzumab and novel agents, such as duvelisib, are needed for patients with relapsed/refractory T-LGLL.

Analysis of a cohort of 279 patients with hairy-cell leukemia (HCL): 10 years of follow-up.

In total, 279 patients with hairy-cell leukemia (HCL) were analyzed, with a median follow-up of 10 years. Data were collected up to June 2018. We analyzed responses to treatment, relapses, survival, and the occurrence of second malignancies during follow-up. The median age was 59 years. In total, 208 patients (75%) were treated with purine analogs (PNAs), either cladribine (159) or pentosatin (49), as the first-line therapy. After a median follow-up of 127 months, the median overall survival was 27 years, and the median relapse-free survival (RFS) was 11 years. The cumulative 10-year relapse incidence was 39%. In patients receiving second-line therapy, the median RFS was 7 years. For the second-line therapy, using the same or another PNA was equivalent. We identified 68 second malignancies in 59 patients: 49 solid cancers and 19 hematological malignancies. The 10-year cumulative incidences of cancers, solid tumors, and hematological malignancies were 15%, 11%, and 5.0%, respectively, and the standardized incidence ratios were 2.22, 1.81, and 6.67, respectively. In multivariate analysis, PNA was not a risk factor for second malignancies. HCL patients have a good long-term prognosis. PNAs are the first-line treatment. HCL patients require long-term follow-up because of their relatively increased risk of second malignancies.

Immune recovery uveitis in a patient with herpes retinitis as a complication of hairy cell leukaemia. / Respuesta similar a la uveítis de recuperación inmune en un paciente con retinitis herpética como complicación de una leucemia de células peludas.

A 51 year-old man with hairy cell leukaemia was treated with pentostatin. While receiving the treatment, he was diagnosed with herpes retinitis in his right eye. After the last cycle of pentostatin the patient developed a mild vitritis and cystoid macular oedema. There were no signs of herpes retinitis reactivation. After excluding other possible causes of intraocular inflammation, a diagnosis of immune recovery uveitis was made. The patient was treated with 2-monthly retro-septal injections of triamcinolone, oral corticosteroids, intravitreal dexamethasone implants and, finally, pars plana vitrectomy. An immune recovery uveitis-like response is possible in HIV negative individuals. The immune reconstitution after the treatment of hairy cell leukaemia may have led to intraocular inflammation. Management of immune recovery uveitis is challenging and difficult. Pars plana vitrectomy may be necessary. Ophthalmologists should be alert to the possibility of immune recovery uveitis in HIV negative patients.

Cordycepin (3'-deoxyadenosine) and pentostatin (deoxycoformycin) against Trypanosoma cruzi.

The aim of this study was to evaluate in vitro the efficacy of cordycepin and pentostatin (alone or combined) against Trypanosoma cruzi, as well as the therapeutic efficiency of protocols of cordycepin and pentostatin combinations in mice experimentally infected with T. cruzi. In vitro, the cordycepin (3'-deoxyadenosine) and pentostatin (deoxycoformycin) exerted potent trypanocidal effect against T. cruzi (Colombian strain), similarly to benznidazole, which is the reference drug. For epimastigotes, the lethal dose of cordycepin capable of killing 50% (LD50) and 20% (LD20) of the parasites was 0.072 and 0.031 mg/mL, respectively and for trypomastigotes was 0.047 and 0.015 mg/mL, respectively. The combined use of cordycepin and pentostatin resulted in a LD50 and LD20 for epimastigotes of 0.068 and 0.027 mg/mL, respectively, as well as 0.056 and 0.018 mg/mL for trypomastigotes, respectively. In vivo, the combined use of cordycepin and pentostatin did not show the expected curative effect, however it was able to control the parasitema in the peak period. In summary, the combination of cordycepin and pentostatin showed no curative effect in mice infected by T. cruzi, despite the in vitro reduction of epimastigotes and trypomastigotes.

Autologous CD19-Targeted CAR T Cells in Patients with Residual CLL following Initial Purine Analog-Based Therapy.

Patients with residual chronic lymphocytic leukemia (CLL) following initial purine analog-based chemoimmunotherapy exhibit a shorter duration of response and may benefit from novel therapeutic strategies. We and others have previously described the safety and efficacy of autologous T cells modified to express anti-CD19 chimeric antigen receptors (CARs) in patients with relapsed or refractory B cell acute lymphoblastic leukemia and CLL. Here we report the use of CD19-targeted CAR T cells incorporating the intracellular signaling domain of CD28 (19-28z) as a consolidative therapy in 8 patients with residual CLL following first-line chemoimmunotherapy with pentostatin, cyclophosphamide, and rituximab. Outpatients received low-dose conditioning therapy with cyclophosphamide (600 mg/m2), followed by escalating doses of 3 × 106, 1 × 107, or 3 × 107 19-28z CAR T cells/kg. An objective response was observed in 3 of 8 patients (38%), with a clinically complete response lasting more than 28 months observed in two patients. Self-limited fevers were observed post-CAR T cell infusion in 4 patients, contemporaneous with elevations in interleukin-6 (IL-6), IL-10, IL-2, and TGF-α. None developed severe cytokine release syndrome or neurotoxicity. CAR T cells were detectable post-infusion in 4 patients, with a longest observed persistence of 48 days by qPCR. Further strategies to enhance CAR T cell efficacy in CLL are under investigation.

The successful use of radiofrequency-induced heat therapy for cutaneous leishmaniasis: a review.

The present gold standard of the treatment of cutaneous leishmaniasis (CL) is pentavalent antimonials either sodium stibogluconate (Pentostam) or meglumine antimoniate (Glucantime), These drugs are quite toxic. They are given by injection and usually administered intramuscularly or intravenously for three weeks or intralesionally for seven or more weeks. That is why the successful introduction of radiofrequency-induced heat therapy using a Thermomed™ 1.8 instrument administered in a single application, with minimal toxic effects, is so important for the treatment of CL.

Pentostatin therapy for steroid-refractory acute graft versus host disease: identifying those who may benefit.

We report outcomes of 60 patients with steroid-refractory (SR)-aGVHD treated with pentostatin. Almost half (47%) of patients had grade 4 GVHD-22% had stage 3-4 liver GVHD and 51% had stage 3-4 lower gastrointestinal tract (LGI) GVHD. Patients received a median of 3 courses (range, 1-9) of pentostatin. Day 28 overall response rate (ORR) was 33% (n = 20) (complete response 18% (n = 11), partial response 15% (n = 9)). Non-relapse mortality was 72% (95% confidence interval (CI) 61-84%) and overall survival (OS) was 21% (95% CI 12-32%) at 18 months. On univariate analysis, age >60 years (HR 1.9, 95% CI 1.01-3.7, p = 0.045) and presence of liver GVHD (HR 1.9, 95% CI 1.9, 95% CI 1.5-3.3, p = 0.03) were significant predictors of poor OS while patients with LGI GVHD had superior OS than those without (HR 0.4, 95% CI 0.2-0.8, p = 0.01). On stratified analysis, patients <60 years with isolated LGI GVHD had the best outcomes with an ORR of 48% and OS of 42% at 18 months. Among older patients, OS was 14% in those with isolated LGI aGVHD and 0% in others. Pentostatin remains a viable treatment option for SR-aGVHD, especially in patients 60 years or younger with isolated LGI involvement.

Treatment with 3'-deoxyadenosine and deoxycoformycin in mice infected by Trypanosoma cruzi and its side effect on purinergic enzymes.

The aim of this study was to evaluate the efficacy of 3'-deoxyadenosine and deoxycoformycin combination in the treatment of mice infected by T. cruzi, as well as to verify the influence of the treatment on purinergic enzymes. Heart and serum samples were collected from 60 mice (30 infected and 30 uninfected) at day 12 post-infection. To verify treatment efficacy, parasitemia was monitored, and the treatment with 3'-deoxy adenosine and deoxycoformycin combination was able to reduce it, but had no curative effect on mice. Seric activities of NTPDase (ATP and ADP substrate) and ADA were increased significantly in untreated mice infected by T. cruzi compared to the negative control, as well as mice treated with 3'-deoxyadenosine and deoxycoformycin (alone or combined) modulated the activity of NTPDase (ATP and ADP substrate), preventing them from increasing in infected animals (activity similar to healthy animals). Treatment with deoxycoformycin alone and associated with 3'-deoxyadenosine modulated the activity of ADA preventing them from increasing in infected animals. However, seric activities of ADA in mice treated with 3'-deoxyadenosine (cordycepin) alone does not modify the ADA activity compared with infected and non-treated mice. However, the 5'-nucleotidase activity decreased significantly in infected untreated animals and the same occurred in infected and treated animals with deoxycoformycin and 3'-deoxyadenosine. However, treatment with deoxycoformycin associated with 3'-deoxyadenosine preventing them from decreasing the 5'-nucleotidase activity. Therefore, we conclude that the treatments did not have curative success for mice infected by T. cruzi. However, the treatments were able to modulate the purinergic enzymes during the infection by T. cruzi, which may contribute to reduce the inflammatory damage in heart.

Long-Term Outcomes of Hairy Cell Leukemia Treated With Purine Analogs: A Comparison With the General Population.

Hairy cell leukemia (HCL) is a rare hematologic malignancy with high response rates and long progression-free survival (PFS) after treatment with purine nucleoside analogs (PNAs; Pentostatin/Cladribine). However, treatment is not curative, and subsequent treatment at relapse is often required. Rechallenge with a purine analog is commonly implemented despite limited data regarding the efficacy of this approach. We retrospectively analyzed 61 consecutive patients with HCL diagnosed between 1995 and 2013 at Cleveland Clinic. Median follow-up was 72 months (3-193). Cladribine as first-line therapy was administered to 59 patients (97%). Overall response rate (ORR) was 97%, with 78% of patients achieving complete remission (CR). PFS after response was significantly improved for patients who achieved CR compared with those with a partial remission (PR) (5-year PFS 71% vs. 39%, respectively [P = .004]). Of the 19 patients who relapsed, 12 received PNAs as second-line treatment with an ORR (83%) comparable to what these patients had with first-line treatment (ORR 92%). Overall survival of all 61 patients was excellent and superior to that of age-, sex-, and race-matched controls from the general population, possibly due to selection bias. In an analysis of a larger cohort of unselected patients in the Surveillance, Epidemiology, and End Results (SEER) database, we found that mortality rates for patients with HCL were similar to those of the general population approximately 5 years after diagnosis. These data confirm the excellent prognosis for patients with HCL after first- and second-line PNA therapy.

Characteristics and treatment patterns among US patients with hairy cell leukemia: a retrospective claims analysis.

AIM: Describe hairy cell leukemia (HCL) treatment patterns using a large, nationally representative US database. PATIENTS & METHODS: Adults newly diagnosed with HCL (1 January 2006 to 30 June 2014) with continuous health plan enrollment ≥180 days pre- and 90 days post-diagnosis were identified from the QuintilesIMS PharMetrics Plus Health Plan Claims Database. Treatment patterns by line of therapy were assessed over the variable follow-up. RESULTS: Among 749 HCL patients (77.4% male; mean age 55.6; mean 32.3 months follow-up), only 37.7% initiated first-line therapy during the available follow-up in a mean of 4.4 months following diagnosis; the majority (75.5%) received cladribine (mean duration 7.3 days). Thirty-eight patients (5.1%) received second-line treatment. CONCLUSION: Over 2.7 years follow-up, more than a third of patients initiated first-line therapy which appeared to provide a long-lasting response.

How I manage patients with hairy cell leukaemia.

Patients with hairy cell leukaemia (HCL) have highly favourable outcomes after purine analogue therapy. However, most patients subsequently relapse and require re-treatment. A minority of patients develop purine analogue-refractory disease. Targeted therapies have improved outcomes for such patients. Recently, the BRAF V600E mutation was identified in most patients with classical HCL, resulting in constitutive mitogen-activated protein kinase pathway activation; impressive responses are achieved in heavily pre-treated patients with BRAF inhibition. The CD22-targeted immunoconjugate moxetumomab pasudotox and BTK inhibitor ibrutinib also achieve responses in relapsed and refractory patients. HCL variant and the IGHV4-34 molecular variant of HCL lack BRAF mutation and have inferior outcomes with standard purine analogue therapy. The addition of rituximab to purine analogues achieves very high rates of minimal residual disease-negative complete remission and improves outcomes for patients with HCL variant. Given the rarity of HCL, optimal integration of novel therapies into treatment algorithms will require well-designed, collaborative studies.

Consensus guidelines for the diagnosis and management of patients with classic hairy cell leukemia.

Hairy cell leukemia is an uncommon hematologic malignancy characterized by pancytopenia and marked susceptibility to infection. Tremendous progress in the management of patients with this disease has resulted in high response rates and improved survival, yet relapse and an appropriate approach to re-treatment present continuing areas for research. The disease and its effective treatment are associated with immunosuppression. Because more patients are being treated with alternative programs, comparison of results will require general agreement on definitions of response, relapse, and methods of determining minimal residual disease. The development of internationally accepted, reproducible criteria is of paramount importance in evaluating and comparing clinical trials to provide optimal care. Despite the success achieved in managing these patients, continued participation in available clinical trials in the first-line and particularly in the relapse setting is highly recommended. The Hairy Cell Leukemia Foundation convened an international conference to provide common definitions and structure to guide current management. There is substantial opportunity for continued research in this disease. In addition to the importance of optimizing the prevention and management of the serious risk of infection, organized evaluations of minimal residual disease and treatment at relapse offer ample opportunities for clinical research. Finally, a scholarly evaluation of quality of life in the increasing number of survivors of this now manageable chronic illness merits further study. The development of consensus guidelines for this disease offers a framework for continued enhancement of the outcome for patients.

Cross-resistance and synergy with bendamustine in chronic lymphocytic leukemia.

Bendamustine (BEN) has structural similarities to an alkylating agent and a nucleoside analog, and effective against tumor cells that are resistant to standard therapy. In this study we compared the activities of BEN against that of the alkylating agent, chlorambucil (CLB), and the nucleoside analogs, fludarabine (FLU) and deoxyadenosine/pentostatin (dADO/PEN), in primary chronic lymphocytic leukemia (CLL) cells in vitro. Cross-resistance was observed between BEN, CLB and FLU, with previously treated patients or those with a deletion 17p being most resistant. In contrast, some resistant CLL cells retained moderate sensitivity to dADO/PEN. Like FLU and CLB, BEN induced apoptosis through both the mitochondrial and death receptor pathways. There was a greater increase in DNA double-strand breaks (DSB) following FLU, as compared to BEN and CLB. Synergistic cytotoxicity was seen on combining BEN or CLB with FLU or dADO/PEN, but not when combining BEN with CLB. These results demonstrate that BEN acts as an alkylating agent, demonstrates cross-resistance to CLB and FLU and resistance to cells with a del 17p. Synergistic cytotoxic activity was seen between BEN and dADO/PEN suggesting that the combination of BEN and PEN should be evaluated in the clinic.

Graft-versus-host disease after radiation therapy in patients who have undergone allogeneic stem cell transplantation: two case reports.

BACKGROUND: Patients who undergo allogeneic stem cell transplantation and subsequent radiation therapy uncommonly develop graft-versus-host disease within the irradiated area. We quantified the incidence of this complication, which is a novel contribution to the field. From 2010 to 2014, 1849 patients underwent allogeneic stem cell transplantation, and 41 (2 %) received radiation therapy afterward. Of these, two patients (5 %) developed graft-versus-host disease within the irradiated tissues during or immediately after radiation therapy. CASE PRESENTATION: The first patient is a 37-year-old white man who had Hodgkin lymphoma; he underwent allogeneic stem cell transplantation from a matched unrelated donor and received radiation therapy for an abdominal and pelvic nodal recurrence. After 28.8 Gy, he developed grade 4 gastrointestinal graft-versus-host disease, refractory to tacrolimus and steroids, but responsive to pentostatin and photopheresis. The other patient is a 24-year-old white man who had acute leukemia; he underwent allogeneic stem cell transplantation from a matched related donor and received craniospinal irradiation for a central nervous system relapse. After 24 cobalt Gy equivalent, he developed severe cutaneous graft-versus-host disease, sharply delineated within the radiation therapy field, which was responsive to tacrolimus and methylprednisolone. CONCLUSIONS: We conclude that graft-versus-host disease within irradiated tissues is an uncommon but potentially serious complication that may follow radiation therapy in patients who have undergone allogeneic stem cell transplantation. Clinicians must be aware of this complication and prepared with strategies to mitigate risk. Patients who have undergone allogeneic stem cell transplantation represent a unique population that may offer novel insight into the pathways involved in radiation-related inflammation.

Solid tumor therapy by selectively targeting stromal endothelial cells.

Engineered tumor-targeted anthrax lethal toxin proteins have been shown to strongly suppress growth of solid tumors in mice. These toxins work through the native toxin receptors tumor endothelium marker-8 and capillary morphogenesis protein-2 (CMG2), which, in other contexts, have been described as markers of tumor endothelium. We found that neither receptor is required for tumor growth. We further demonstrate that tumor cells, which are resistant to the toxin when grown in vitro, become highly sensitive when implanted in mice. Using a range of tissue-specific loss-of-function and gain-of-function genetic models, we determined that this in vivo toxin sensitivity requires CMG2 expression on host-derived tumor endothelial cells. Notably, engineered toxins were shown to suppress the proliferation of isolated tumor endothelial cells. Finally, we demonstrate that administering an immunosuppressive regimen allows animals to receive multiple toxin dosages and thereby produces a strong and durable antitumor effect. The ability to give repeated doses of toxins, coupled with the specific targeting of tumor endothelial cells, suggests that our strategy should be efficacious for a wide range of solid tumors.

New Life for Immunotoxin Cancer Therapy.

Immunotoxins are targeted anticancer therapeutics that kill cancer cells using a cytotoxic bacterial toxin payload. Their development for use in solid tumor malignancies was delayed due to issues with their immunogenicity and limited therapeutic window. However, new research has rejuvenated the field. Coadministration with a lymphocyte-depleting regimen of pentostatin and cyclophosphamide can delay antidrug antibody formation, increasing the number of treatment cycles that patients can receive and resulting in durable responses in heavily pretreated patients. In addition, a new generation of immunotoxin molecules with reduced immunogenicity and nonspecific toxicity has been developed through protein engineering techniques, and one has recently entered the clinic. In preclinical studies in mouse models, these new agents are effective against many tumor types as single agents, and also produce synergistic antitumor responses in combination with chemotherapy. These new immunotoxins have renewed excitement in the field and may prove a promising addition to the targeted therapy repertoire.