Ponatinib evaluation and safety in real-life chronic myelogenous leukemia patients failing more than two tyrosine kinase inhibitors: the PEARL observational study

Ponatinib represents a remarkable progress in the treatment of heavily pretreated chronic myelogenous leukemia (CML) and de novo Philadelphia chromosome-positive ALL patients despite significant toxicity in clinical trials. To date, "real-life" data remain few and the use of ponatinib in this setting and its consequences remain mostly unknown. We report, within a national observational study, the use of ponatinib in unselected CML patients who had previously failed ≥2 lines of tyrosine kinase inhibitor (TKI) therapy (or one line if an Abelson (ABL)^T315I mutation was identified), in real-life conditions (2013-2014) in a compassionate program. Our analysis has been focused on 48 chronic phase CML patients recorded. With a median follow-up of 26.5 months since ponatinib initiation, the overall survival (OS) rates (80.5% at 3 years) and cumulative incidence of major molecular response (81.8% at 18 months) were similar to those of the phase II study, with no influence of BCR-ABL mutations nor the reason of ponatinib prescription. A specific subanalysis of the preexisting cardiovascular risk factors and events occurring on ponatinib is described. These events occurred after a median time on ponatinib of 5.8 months (excluding hypertension) and were observed in 29/48 patients (47%), even in those already on anti-aggregants/coagulants. The majority were not severe and resolved, but two cases were fatal. Other hematological or nonhematological nonvascular adverse events were similar to those previously described in trials. This observational study reports similar rates of survival, molecular responses, and a slight increase in the cardiovascular toxicity of ponatinib in real-life conditions, prompting improved control of cardiovascular risk factors and selection of patients.

ABO-mismatched marrow processing for transplantation: results of 114 procedures and analysis of immediate adverse events and hematopoietic recovery

BACKGROUND

Red cell (RBC) depletion is needed to bypass ABO mismatch in allogeneic bone marrow transplantation (BMT). Technical and clinical data obtained after bone marrow (BM) processing with a continuous-flow cell separator (Cobe Spectra, Gambro BCT) are reported.

STUDY DESIGN AND METHODS

RBC depletion and recovery of nucleated cells, CD3+ cells, CD34+ cells, and colony-forming unit-granulocyte-macrophage were calculated. Bacteriologic contaminations, side effects of graft infusion, and hematopoietic recovery were analyzed.

RESULTS

A total of 114 BM samples were processed. The mean volume collected was 1099 mL (range, 390-2450 mL). Initial and residual mean RBCs volumes were 309.9 and 4.0 mL corresponding to a depletion of 98.6 +/- 0.78 percent. Before processing, the mean numbers of nucleated cells, granulocytes, CD3+ cells, CD34+ cells, and CFU-GM were 20.28 x 10(9), 12.79 x 10(9), 1.96 x 10(9), 356.7 x 10(6), and 195.6 x 10(5), respectively. The mean corresponding recoveries after processing were 33.66, 48.98, 82.02, 82.2, and 93.9 percent. Limited side effects were observed in 14 patients without correlation with residual RBCs volume. All but two patients engrafted.

CONCLUSION

BM processing with the Cobe Spectra cell separator provides high rates of RBC depletion without significant side effects after BMT.

Nilotinib and peginterferon alfa-2a for newly diagnosed chronic-phase chronic myeloid leukaemia (NiloPeg): a multicentre, non-randomised, open-label phase 2 study

BACKGROUND

Nilotinib is now recommended for patients with newly diagnosed chronic myeloid leukaemia in chronic phase and leads to important rates of molecular response 4·5 log (MR(4·5)), allowing the prospect of therapy cessation. However, most patients do not reach this criterion and nilotinib is taken for lengthy periods, resulting in chronic or late-onset adverse events. Nilotinib combined with interferon might further increase rates of MR(4·5), avoid late side-effects, and allow therapy cessation. In a phase 2 trial we aimed to assess the feasibility, safety, and deep molecular response of the combination of nilotinib (600 mg daily) and peginterferon alfa-2a in newly diagnosed patients with chronic-phase chronic myeloid leukaemia (CML).

METHODS

In a non-randomised, open-label, phase 2 trial, we enrolled adult patients (age ≥18 years) without any organ failure who had BCR-ABL-positive, chronic-phase CML, at diagnosis. After a priming procedure with 90 μg per week of peginterferon alfa-2a alone for a month, we gave patients peginterferon alfa-2a 45 μg per week combined with nilotinib 600 mg daily until 24 months after interferon initiation. The primary endpoint was the cumulative incidence of MR(4·5) at 12 months after initiation of peginterferon alfa-2a. Data were analysed by a modified intention-to-treat principle. This trial is registered at the European Clinical Trials Database (EudraCT), number 2010-019786-28.

FINDINGS

Between March 24, 2011, and Sept 27, 2011, we enrolled 42 patients. One patient withdrew consent before receiving any study treatment so was excluded from analysis; 41 patients received treatment with peginterferon alfa-2a and nilotinib. At 12 months, seven (17%) patients had achieved MR(4·5). Haematological and hepatic adverse events were frequent-with grade 3-4 neutropenias occurring in ten (24%) patients, grade 3-4 thrombocytopenias occurring in ten (24%) patients, grade 3-4 cholestatic events occurring in seven (17%) patients, and grade 3-4 elevations in aspartate aminotransferase or alanine aminotransferase occurring in three (7% patients-particularly during the first 3 months. However, 30 (73%) patients remained on interferon therapy at 1 year. Three grade 3-4 cardiac events (7% of patients, all coronary stenoses) occurred at later timepoints.

INTERPRETATION

The combination of peginterferon alfa-2a resulted in good molecular responses in patients. Despite substantial toxic effects, most patients remained on the study drugs for more than a year. This combination should now be tested in a randomised controlled trial.

FUNDING

Novartis Pharma.

Ponatinib in chronic myeloid leukemia (CML): Consensus on patient treatment and management from a European expert panel

Five tyrosine kinase inhibitors (TKIs) are currently approved in the European Union for treatment of chronic myeloid leukemia (CML) and all have considerable overlap in their indications. While disease-specific factors such as CML phase, mutational status, and line of treatment are key to TKI selection, other important features must be considered, such as patient-specific comorbidities and TKI safety profiles. Ponatinib, the TKI most recently approved, has demonstrated efficacy in patients with refractory CML, but is associated with an increased risk of arterial hypertension, sometimes severe, and serious arterial occlusive and venous thromboembolic events. A panel of European experts convened to discuss their clinical experience in managing patients with CML. Based on the panel discussions, scenarios in which a CML patient may be an appropriate candidate for ponatinib therapy are described, including presence of the T315I mutation, resistance to other TKIs without the T315I mutation, and intolerance to other TKIs.

A comparison of the functional durability of the AMS 800 artificial urinary sphincter between cases with and without an underlying neurogenic aetiology

AIM

To compare the efficacy and functional durability of the American Medical Systems 800 (AMS 800) artificial urinary sphincter (AUS) device for patients with neurogenic and non-neurogenic incontinence.

METHODS

From 1985 to 2000, 38 patients underwent implantation of an AMS 800 AUS at our institution. Thirty of these patients had complete records and follow-up data available. The mean follow-up for these two groups of patients was six years. Seventeen devices (57%) were implanted for non-neurogenic indications including incontinence after prostatectomy or hysterectomy. Thirteen devices (43%) were implanted for neurogenic conditions including spina bifida, spinal cord injury or severe pelvic trauma. The primary end point measured was continence. Secondary end points included mechanical and non-mechanical device failure, re-operation and complication rates between the two groups.

RESULTS

In the neurogenic group, only two patients (15%) have their original device in situ without revisions. Only three patients (23%) in this group are entirely dry. In contrast, seven patients (41%) in the non-neurogenic group are completely dry with their original device in situ. A further four (23%) are entirely dry after device revision or replacement surgery. The rates of mechanical failure were not statistically different between the two groups. The rate of non-mechanical failure (NMF) was statistically greater in the neurogenic group in comparison to that in the non-neurogenic group (p < 0.05).

CONCLUSIONS

Insertion of an AMS 800 artificial sphincter remains a durable means of regaining urinary continence. Patients who are incontinent as a result of an underlying neurological deficit should be counselled that they might have a higher risk of non-mechanical device failure, requirement for re-operation and that their overall long-term continence rates may be poor.

Time to stop operating on breast cancer patients with pathological complete response?

Surgery is an obligatory component of treatment for early breast cancer. The last 20 years developments in systemic neoadjuvant therapy have progressively increased pathological complete response (pCR). Pathological complete response is associated with excellent prognosis especially for hormone receptor negative cancers. Therapeutic advances and recognition of the importance of pathological subtype in predicting pCR facilitate identification of subgroups with very high pCR rates. Treatment of HER2 positive hormone receptor negative cancers with combination chemotherapy and multiple targeted anti-HER2 agents results in consistently high pCR rates of 60-83%. Routine surgery in this setting where most patients have no potential to benefit is of questionable value and the option of omitting surgery in these patients should now be explored in a randomized trial. For HER2 positive disease not achieving pCR after neoadjuvant treatment the outcomes are poor. Trials are underway to determine if outcomes for these patients can be improved with alternative targeted therapy.

How I manage relapse of chronic myeloid leukaemia after stopping tyrosine kinase inhibitor therapy

During the last 10 years, clinical trials formally demonstrated that about 50% of patients with chronic phase (CP) chronic myeloid leukaemia (CML) who achieve and maintain deep molecular responses for a prolonged period of time during treatment with imatinib or new generation tyrosine kinase inhibitors (TKIs) may successfully stop their anti-leukaemic therapy. Based on the accumulated knowledge from abundant clinical trial experience, TKI discontinuation is becoming an important goal to achieve and is about to enter clinical practice. This review focuses on relapse definition, laboratory tests to identify relapse and relapse management after TKI discontinuation.

ETNK1 mutations induce a mutator phenotype that can be reverted with phosphoethanolamine

Recurrent somatic mutations in ETNK1 (Ethanolamine-Kinase-1) were identified in several myeloid malignancies and are responsible for a reduced enzymatic activity. Here, we demonstrate in primary leukemic cells and in cell lines that mutated ETNK1 causes a significant increase in mitochondrial activity, ROS production, and Histone H2AX phosphorylation, ultimately driving the increased accumulation of new mutations. We also show that phosphoethanolamine, the metabolic product of ETNK1, negatively controls mitochondrial activity through a direct competition with succinate at mitochondrial complex II. Hence, reduced intracellular phosphoethanolamine causes mitochondria hyperactivation, ROS production, and DNA damage. Treatment with phosphoethanolamine is able to counteract complex II hyperactivation and to restore a normal phenotype.

Rapid onset of peripheral artery disease in a chronic myeloid leukemia patient without prior arterial disorder: direct relationship with nilotinib exposure and clinical outcome

The second-generation tyrosine kinase inhibitor (TKI) of the BCR-ABL1 oncoprotein nilotinib used in patients with chronic myeloid leukemia is suspected to increase the risk of arterial occlusion, especially in patients with pre-existing cardiovascular risk factors or established cardiovascular diseases. Here, we describe a case of unexpected and rapid onset of symptomatic peripheral artery disease (PAD) associated with silent stenosis of digestive and renal arteries in a nilotinib-treated patient devoid of significant cardiovascular diseases (CVD) risk factor, prior atherosclerotic disease, or other cause of arterial damage. This is the first report to establish a direct relationship between nilotinib exposure and PAD and to reveal that arterial damage is irreversible despite rapid drug withdrawal. However, functional outcome was favorable upon rapid TKI replacement, specific cardiovascular disease management, and development of collateral arterial network.

CD34+ progenitors are reproducibly recovered in thawed umbilical grafts, and positively influence haematopoietic reconstitution after transplantation

Cord blood (CB) units are increasingly used for allogeneic transplantation. Cell dose, a major factor for CB selection, is evaluated before freezing by each CB bank, using various techniques. This may introduce variability and affect the prediction of cell recovery after thawing, or haematopoietic reconstitution. Forty-two children were transplanted at the same institution with unrelated CB units. All units were thawed and evaluated at the same cell therapy facility, using standard procedures. We investigated: (i) factors that affect cell loss after thawing, and (ii) the importance of CD34(+) cell doses. Prefreeze and post-thaw CD34(+) cell doses were statistically correlated, thus suggesting that variability in numeration techniques used by different CB banks does not compromise the biological and clinical value of these figures. CD34(+) cell recovery appeared to be correlated with the absolute number of CD34(+) cells per frozen bag. Infused CD34(+) is the cell dose that better correlates with platelet reconstitution delay; in addition, when using a quartile comparison, haematopoietic recovery appeared to be related with prefreeze and post-thaw CD34(+) cell doses. We conclude that enumeration of CD34(+) cells in CB units is of biological significance, and may help select CB units and identify patients at risk of delayed recovery.

Regulation of estradiol 17 beta-hydroxysteroid dehydrogenase expression and activity by retinoic acid in T47D breast cancer cells

Estradiol 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) mediates the interconversion of estrone and estradiol in endocrine-responsive tissues such as the breast. The control of 17 beta HSD expression by all-trans-retinoic acid (RA) in T47D breast cancer cells was examined using a specific 17 beta HSD complementary DNA probe. Two main 17 beta HSD messenger RNA (mRNA) transcripts of 2.2 and 1.3 kilobases (kb) were detected, of which only the 1.3-kb mRNA was regulated. RA increased expression of the 17 beta HSD 1.3-kb mRNA in a dose- and time-dependent manner, and the increased expression of this mRNA by RA was inhibited by a 10-fold excess of a RA antagonist Ro 41-5253. Insulin-like-growth factor-I, interleukin-1, and estradiol, previously shown to increase 17 beta HSD activity in breast cancer cells, had little effect on 17 beta HSD gene expression. To relate the effect of increased 17 beta HSD 1.3-kb mRNA expression to 17 beta HSD activity, the conversion of estrone to estradiol (reductive) and that of estradiol to estrone (oxidative) were measured in intact T47D cell monolayers. Whereas RA increased 17 beta HSD reductive activity, it had no effect on oxidative activity. The addition of excess NAD increased 17 beta HSD oxidative activity in control and RA-treated cells, but the addition of NADH had no effect on 17 beta HSD reductive activity. These results suggest that the increased expression of the 17 beta HSD 1.3-kb mRNA induced by RA is associated with an increase in 17 beta HSD reductive activity, but that endogenous cofactor levels may determine the direction in which this enzyme acts in T47D cells.

Ponatinib after failure of second-generation tyrosine kinase inhibitor in resistant chronic-phase chronic myeloid leukemia

Ponatinib, the only third-generation pan-BCR::ABL1 inhibitor with activity against all known BCR::ABL1 mutations including T315I, has demonstrated deep and durable responses in patients with chronic-phase chronic myeloid leukemia (CP-CML) resistant to prior second-generation (2G) TKI treatment. We present efficacy and safety outcomes from the Ponatinib Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and CML Evaluation (PACE) and Optimizing Ponatinib Treatment in CP-CML (OPTIC) trials for this patient population. PACE (NCT01207440) evaluated ponatinib 45 mg/day in CML patients with resistance to prior TKI or T315I. In OPTIC (NCT02467270), patients with CP-CML and resistance to ≥2 prior TKIs or T315I receiving 45 or 30 mg/day reduced their doses to 15 mg/day upon achieving ≤1% BCR::ABL1^IS or received 15 mg/day continuously. Efficacy and safety outcomes from patients with CP-CML treated with ≥1 2G TKI (PACE, n = 257) and OPTIC (n = 93), 45-mg starting dose cohort, were analyzed for BCR::ABL1^IS response rates, overall survival (OS), progression-free survival (PFS), and safety. By 24 months, the percentages of patients with ≤1% BCR::ABL1^IS response, PFS, and OS were 46%, 68%, and 85%, respectively, in PACE and 57%, 80%, and 91%, respectively, in OPTIC. Serious treatment-emergent adverse events and serious treatment-emergent arterial occlusive event rates were 63% and 18% in PACE and 34% and 4% in OPTIC. Ponatinib shows high response rates and robust survival outcomes in patients whose disease failed prior to 2G TKIs, including patients with T315I mutation. The response-based dosing in OPTIC led to improved safety and similar efficacy outcomes compared with PACE.

Asciminib monotherapy in patients with CML-CP without BCR::ABL1 T315I mutations treated with at least two prior TKIs: 4-year phase 1 safety and efficacy results

Asciminib is approved for patients with Philadelphia chromosome-positive chronic-phase chronic myeloid leukemia (CML-CP) who received ≥2 prior tyrosine kinase inhibitors or have the T315I mutation. We report updated results of a phase 1, open-label, nonrandomized trial (NCT02081378) assessing the safety, tolerability, and antileukemic activity of asciminib monotherapy 10-200 mg once or twice daily in 115 patients with CML-CP without T315I (data cutoff: January 6, 2021). After ≈4-year median exposure, 69.6% of patients remained on asciminib. The most common grade ≥3 adverse events (AEs) included increased pancreatic enzymes (22.6%), thrombocytopenia (13.9%), hypertension (13.0%), and neutropenia (12.2%); all-grade AEs (mostly grade 1/2) included musculoskeletal pain (59.1%), upper respiratory tract infection (41.7%), and fatigue (40.9%). Clinical pancreatitis and arterial occlusive events (AOEs) occurred in 7.0% and 8.7%, respectively. Most AEs occurred during year 1; the subsequent likelihood of new events, including AOEs, was low. By data cutoff, among patients without the indicated response at baseline, 61.3% achieved BCR::ABL1 ≤ 1%, 61.6% achieved ≤0.1% (major molecular response [MMR]), and 33.7% achieved ≤0.01% on the International Scale. MMR was maintained in 48/53 patients who achieved it and 19/20 who were in MMR at screening, supporting the long-term safety and efficacy of asciminib in this population.

Imatinib mesylate minimally affects bcr-abl+ and normal monocyte-derived dendritic cells but strongly inhibits T cell expansion despite reciprocal dendritic cell-T cell activation

In chronic myeloid leukemia, bcr-abl+ monocytes provide a unique opportunity to generate dendritic cells (DC) expressing a broad spectrum of leukemic antigens, and bcr-abl+ DC vaccines may allow immunological eradication of leukemic cells persisting under treatment with the tyrosine kinase inhibitor imatinib. However, the efficiency of bcr-abl+ DC vaccines will critically depend on the absence of deleterious effects of bcr-abl and of imatinib on DC functions. We show that bcr-abl+ monocytes, devoid of contamination of CD14low granulocytic precursors, differentiate into DC with typical immunophenotypical and functional features, and bcr-abl transcription decreases simultaneously. During differentiation, imatinib induces a slight increase of DC apoptosis and prevents CD1a up-regulation in a dose-dependent manner in bcr-abl+ and normal monocyte-derived DC, but at most, 25% of DC fail to acquire CD1a. When DC maturation is induced in the presence of imatinib, bcr-abl+ and normal monocyte-derived DC up-regulate major histocompatibility complex and costimulatory molecules, CC chemokine receptor 7 and CD83. However, secretion of interleukin-12p70 is decreased in a dose-dependent manner. Imatinib exposure of bcr-abl+ and normal monocyte-derived DC during differentiation and maturation is not detrimental to T cell immunostimulatory functions of DC. In sharp contrast, imatinib, when added to DC-T cell cultures, profoundly suppresses DC-mediated T cell proliferation, despite reciprocal DC-T cell activation attested by up-regulation of CD25 on T cells and of CD86 on DC. Our findings demonstrate that T cells, not normal or bcr-abl+ monocyte-derived DC, are major targets for imatinib immunomodulatory effects. It can be envisioned already that imatinib-free windows will be required to enable vaccination-induced, leukemia-specific T cell expansion.

Strategies for improved antigen delivery into dendritic cells

Efficacious vaccines against cancers and infectious diseases will, in general, need to elicit comprehensive immune responses, including cytotoxic T lymphocyte activity. Because of their unique T cell stimulatory capacities, dendritic cells (DC) have emerged as the most potent antigen-presenting cell. Vaccination strategies should therefore aim at the acquisition and display of the antigen(s) of choice by DC. Results from vaccination studies, in animal models and in humans, stress the need for optimized antigen delivery systems to DC, to increase vaccination efficacy as well as to improve control on the immunological outcome. Here, we discuss the advantages and limitations of several recently described methodologies for antigen delivery into DC.

Prospective flow cytometric evaluation of nucleated red blood cells in cord blood units and relationship with nucleated and CD34+ cell quantification

BACKGROUND

Cord blood (CB) represents an alternate source of stem cells in transplantation. Nucleated red blood cells (NRBCs) are a physiological subset of CB population. Although it is important to have an accurate estimate of CD34(+) cell number, NRBCs could compromise white blood cell count and interfere with CD34(+) cell quantification.

STUDY DESIGN AND METHODS

A total of 826 CB units were analyzed for total nucleated cells (TNCs), NRBCs, and CD34(+) cells by flow cytometry. NRBCs were also counted conventionally by manual microscopy. Percentages of CD34(+) cells corrected by NRBC count (CD34+c) were determined as follows: %CD34+c = CD34(+)/CD45(+) (x10(6))/(TNCs (x10(8)) - NRBCs (x10(8))).

RESULTS

The mean percentages of CD34+ cells and NRBCs were 0.27 percent (range, 0.01%-1.25%) and 7.64 percent (range, 0.13%-84%), respectively. Comparison between flow cytometric and microscopic NRBC count showed a regression of y = 0.685 + 0.719x and a coefficient of determination of r(2) = 0.721. When corrected with NRBC count, the mean percentage of CD34(+) c cells was 0.295 percent (p = 0.0008 compared with CD34(+)%) and mean TNCc count was 14.8 x 10(8) (p < 10(-4) compared to TNC count).

CONCLUSION

The determination of NRBCs with a flow cytometric method might represent a new strategy for providing satisfactory quality assurance controls of CB products.