Uncommon or delayed adverse events associated with imatinib treatment for chronic myeloid leukemia

Discoidin domain receptor 1 may be involved in biological barrier homeostasis

WHAT IS KNOWN AND OBJECTIVE

Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase involved in the pathological processes of several diseases, such as keloid formation, renal fibrosis, atherosclerosis, tumours, and inflammatory processes. The biological barrier is the first line of defence against pathogens, and its disruption is closely related to diseases. In this review, we attempt to elucidate the relationship between DDR1 and the biological barrier, explore the potential biological value of DDR1, and review the current research status and clinical potential of DDR1-selective inhibitors.

METHODS

We conducted an extensive literature search on PubMed to collect studies on the relevance of DDR1 to biological barriers and DDR1-selective inhibitors. With these studies, we explored the relationship between DDR1 and biological barriers and briefly reviewed representative DDR1-selective inhibitors that have been reported in recent years.

RESULTS AND DISCUSSION

First, the review of the potential mechanisms by which DDR1 regulates biological barriers, including the epithelial, vascular, glomerular filtration, blood-labyrinth, and blood-brain barriers. In the body, DDR1 dysfunction and aberrant expression may be involved in the homeostasis of the biological barrier. Secondly, the review of DDR1 inhibitors reported in recent years shows that DDR1-targeted inhibition is an attractive and promising pharmacological intervention.

WHAT IS NEW AND CONCLUSIONS

This review shows that DDR1 is involved in various physiological and pathological processes and in the regulation of biological barrier homeostasis. However, studies on DDR1 and biological barriers are still scarce, and further studies are needed to elucidate their specific mechanisms. The development of targeted inhibitors provides a new direction and idea to study the mechanism of DDR1.

Efficacy and safety profile of generic imatinib in patients with newly diagnosed chronic myeloid leukemia-chronic phase: sharing experience of a hemato-oncology center from eastern India

In India, CML is the commonest adult leukemia. Imatinib is the gold standard for frontline treatment of newly diagnosed CML-CP patients. The present study was conducted to assess the efficacy and safety of generic imatinib in newly diagnosed CML-CP patients. In this prospective study, 76 newly diagnosed CML-CP patients received generic imatinib. They were monitored as per the ELN2013 recommendation. Karyotyping and BCR-ABL transcript level were done at specified time points. Adverse effects, if any, were documented as per the NCI-CTCAE criteria v4.03. Statistical analysis was done using standard methods. A total of 76 patients included in the study; median age was 36 years. The most common (71%) presenting symptom was fatigue; splenomegaly was found in all patients. CHR was achieved in 97% cases. At 3 months, 64.5% patients achieved ERM. At 6 months, CCyR and MCyR had seen in 65% and 68% cases, respectively. MMR achieved at 12 months in 44% cases. Most common hematological and non-hematological toxicity were anemia and skin changes seen in 89.5% and 71% cases, respectively. With generic imatinib therapy, the results of treatment outcome and safety profile were comparable with original imatinib. The added advantage was gross reduction in cost of therapy meeting unmet needs in CML patients in countries with resource constraints.

Long-Term Side Effects of Tyrosine Kinase Inhibitors in Chronic Myeloid Leukemia

Most patients with chronic myeloid leukemia have deep and durable responses when treated with BCR-ABL1 tyrosine kinase inhibitors (TKIs). Imatinib (the first approved TKI), nilotinib, and dasatinib are used in newly diagnosed, relapsed or intolerant patients, while bosutinib and ponatinib are used only in relapsed or intolerant patients. Previously the drug of choice was related to the likelihood of response and, to a small extent, patient comorbidities. The long-term toxicities, particularly cardiopulmonary side effects, are now impacting treatment choice, making patient comorbidities of significant concern. About 10 % of patients do not tolerate their initial BCR-ABL1 TKI and an increasing number are developing long-term side effects, particularly with the second generation drugs. Side effects of the five drugs reviewed here highlight the differences between cardiovascular, pulmonary, gastrointestinal, and endocrine toxicities, as well as possible second malignancies. There is increasing evidence that patients whose disease is controlled by TKI's will have greater impact on their quality of life from comorbidities or drug adverse events than from the disease itself. Research into management of long-term toxicities is needed.

Physiological measurements corroborate symptomatic improvement after therapeutic leukapheresis in a pregnant woman with chronic myelogenous leukemia

Therapeutic leukapheresis can control the white blood cell count (WBC) of pregnant women with chronic myelogenous leukemia (CML) who have hyperleukocytosis without leukostasis. The medical justification for this treatment has not been objectively documented. We report a 27-year-old woman, diagnosed with CML at 10-week gestation, who developed severe dyspnea on exertion. A workup that included chest CT and echocardiography with a bubble study detected no cardiopulmonary pathology to explain her symptoms, and thus she was referred for leukapheresis. Prior to her first leukapheresis, which lowered her WBC from 154 × 10(3) /μL to 133 × 10(3) /μL, her oxygen saturation (SpO2 ) on room air decreased from 98 to 93% during 100 feet of slow ambulation and she was dyspneic. Just after the leukapheresis, her dyspnea on exertion was much improved and her SpO2 remained at 98% with repeat ambulation. Spirometry and lung volume studies obtained before and after her first leukapheresis demonstrated 32 and 31% improvements in forced vital capacity and forced expiratory volume in 1 s respectively, a 25% increase in functional residual capacity, and a 142% improvement in expiratory reserve volume. Residual volume decreased by almost 20%. Three times in a week, leukapheresis was continued until her WBC was controlled with interferon α-2b approximately 4 weeks later. Her dyspnea had completely resolved. She gave birth by elective caesarean section to a healthy boy at 32 weeks. Corroboration of symptom relief by leukapheresis with physiological data may justify such treatment in pregnant patients with CML. J. Clin. Apheresis 31:393-397, 2016. © 2015 Wiley Periodicals, Inc.

Safety and efficacy of imatinib in CML over a period of 10 years: data from the randomized CML-study IV

Tyrosine kinase inhibitors (TKI) have changed the natural course of chronic myeloid leukemia (CML). With the advent of second-generation TKI safety and efficacy issues have gained interest. The randomized CML - Study IV was used for a long-term evaluation of imatinib (IM). 1503 patients have received IM, 1379 IM monotherapy. After a median observation of 7.1 years, 965 patients (64%) still received IM. At 10 years, progression-free survival was 82%, overall survival 84%, 59% achieved MR(5), 72% MR(4.5), 81% MR(4), 89% major molecular remission and 92% MR(2) (molecular equivalent to complete cytogenetic remission). All response levels were reached faster with IM800 mg except MR(5). Eight-year probabilities of adverse drug reactions (ADR) were 76%, of grades 3-4 22%, of non-hematologic 73%, and of hematologic 28%. More ADR were observed with IM800 mg and IM400 mg plus interferon α (IFN). Most patients had their first ADR early with decreasing frequency later on. No new late toxicity was observed. ADR to IM are frequent, but mostly mild and manageable, also with IM 800 mg and IM 400 mg+IFN. The deep molecular response rates indicate that most patients are candidates for IM discontinuation. After 10 years, IM continues to be an excellent initial choice for most patients with CML.

Productive replication of Ebola virus is regulated by the c-Abl1 tyrosine kinase

Ebola virus causes a fulminant infection in humans resulting in diffuse bleeding, vascular instability, hypotensive shock, and often death. Because of its high mortality and ease of transmission from human to human, Ebola virus remains a biological threat for which effective preventive and therapeutic interventions are needed. An understanding of the mechanisms of Ebola virus pathogenesis is critical for developing antiviral therapeutics. Here, we report that productive replication of Ebola virus is modulated by the c-Abl1 tyrosine kinase. Release of Ebola virus-like particles (VLPs) in a cell culture cotransfection system was inhibited by c-Abl1-specific small interfering RNA (siRNA) or by Abl-specific kinase inhibitors and required tyrosine phosphorylation of the Ebola matrix protein VP40. Expression of c-Abl1 stimulated an increase in phosphorylation of tyrosine 13 (Y(13)) of VP40, and mutation of Y(13) to alanine decreased the release of Ebola VLPs. Productive replication of the highly pathogenic Ebola virus Zaire strain was inhibited by c-Abl1-specific siRNAs or by the Abl-family inhibitor nilotinib by up to four orders of magnitude. These data indicate that c-Abl1 regulates budding or release of filoviruses through a mechanism involving phosphorylation of VP40. This step of the virus life cycle therefore may represent a target for antiviral therapy.

Use of tyrosine kinase inhibitors for chronic myeloid leukemia: management of patients and practical applications for pharmacy practitioners

OBJECTIVE

To summarize the use of tyrosine kinase inhibitors (TKIs) for treatment of patients with chronic myeloid leukemia (CML) and provide practical information for patient management.

DATA SOURCES

Literature was retrieved from PubMed (2000-January 2011), using the search terms chronic myeloid leukemia and tyrosine kinase inhibitor. Abstracts presented at the 2008-2010 annual meetings of the American Society of Hematology and the American Society of Clinical Oncology, reference citations from identified publications, as well as the manufacturers' full prescribing information for cited drugs, also were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Articles evaluating the efficacy and safety of the TKIs imatinib, nilotinib, and dasatinib were evaluated. Focus was placed on publications supporting management of patients with CML in the chronic phase. Reports presenting clinical trial information of TKIs in development also were included.

DATA SYNTHESIS

The discovery of targeted tyrosine kinase inhibition of BCR-ABL kinase dramatically changed the treatment of CML. Imatinib, the first TKI approved for treatment of patients with Philadelphia chromosome--positive CML, demonstrated significant superiority over the previous standard of care: interferon plus cytarabine. The newer, more potent TKIs, nilotinib and dasatinib, have demonstrated improved efficacy over imatinib as first-line therapy and provide an effective option for patients with resistance or intolerance to imatinib.

CONCLUSIONS

To maximize efficacy of TKI therapy, close patient management, involving frequent monitoring of patient response, is essential. Given the importance of continuing TKI therapy, early recognition and management of adverse events are critical to optimizing outcomes in patients with CML. In addition to the safety profile and considerations of comorbidities, additional factors can affect therapeutic selection, including drug-drug and drug-food interactions. Research investigating new therapies, particularly for patients harboring the T315I mutation-which remains refractory to current TKIs-continues in the quest to improve outcomes in patients with CML.