Drug Targeting and Therapeutic Management of Chronic Myeloid Leukemia: Conventional and Nanotherapeutic Drug Options

Chronic myeloid leukemia (CML) is a blood cancer predominantly affecting older adult patients. According to the American Cancer Society, an estimated 8,860 people will be diagnosed with CML in 2022. Treatments for CML have evolved with a focus on CML phase severity or progression. Overall, there have been some breakthrough treatment options for a high percentage of patients with CML. This is largely due to the discovery of tyrosine kinase inhibitors (TKI); however, drug resistance continues to present a significant challenge for the management of CML disease.  The use of interferon (IFN), antimetabolites, and bone marrow transplants provide alternative treatment options, but also present with limitations including severe side effects, toxicity, and graft versus host disease. Nanomedicine has demonstrated benefits in terms of efficacy, often reducing or eliminating unwanted toxicities associated with the use of conventional drug agents. This review summarizes rational molecular targets of CML drugs and provides highlights of current FDA-approved agents for the treatment of CML. Additionally, this communication includes an overview of the limitations of conventional treatments and how nanomedicine has addressed challenges encountered during CML treatment. .

Imatinib Efficacy, Safety and Resistance in Iranian Patients with Chronic Myeloid Leukemia: A Review of Literature

Background: Imatinib is the gold standard in the treatment of chronic myeloid leukemia (CML) patients. Resistance to imatinib is interfering with patients’ responses and their survivals.

Materials and Methods: We designed a systematic search to find relevant studies by applying appropriate keywords in PubMed, Web of science, Scopus, Ovid, ProQuest, Science direct and Google scholar for English studies. We also investigated the aforementioned terms’ correspondence in Magiran, Scientific information database (SID) and Google scholar for Persian articles.

Results: 25 studies were selected for final analysis. Reported hematologic responses from adult studies ranged 86-99% and major molecular responses were estimated in 38.84% of our patients within 12 months of treatment. The most frequent reported adverse drug reactions (ADRs) were edema (n=5 studies, 100%) and fatigue and nausea (n=4 studies, 80%); ADR per capita ratio was 1.46. Only one study informed ADRs in pediatrics demonstrating 93% of patients experienced ADRs after receiving imatinib. Most of the Studies (n=4, 67% from 7 studies) considered BCR/ABL point mutation as main reason of imatinib resistance. Drug-binding site and P-loop regions were two common sites for BCR/ABL point mutation.

Conclusion: Imatinib as the first line treatment for CML has been associated with proper and durable responses in Iranian adults and children CML patients. Moreover, Imatinib life-threatening adverse effects were reported uncommon. Various responses to modified regimens have been reported in resistant patients; therefore, individualized treatment based on mutation type could be recommended.

The blue palate-A case series of imatinib-related oral pigmentation and literature review

Pigmented oral mucosal lesions are diverse, and differential diagnosis can range from benign conditions such as oral melanotic macule to malignancies such as oral malignant melanoma. Imatinib mesylate is a tyrosine kinase inhibitor used as a first-line medication in the management of oncohematological conditions such as chronic myeloid leukemia and gastrointestinal stromal tumors. Side effects of imatinib therapy are common, and paradoxically imatinib has been associated with both hypo- and hyperpigmented lesions, the underlying mechanism for which is still unclear. Hyperpigmentation associated with imatinib therapy is a potentially underreported phenomenon. This article presents an in-depth, clinicopathological review of the literature surrounding imatinib-related hyperpigmentation, alongside a case series of imatinib-related oral pigmentation with notable practical learning points. A pragmatic flowchart to help clinicians in the diagnosis and management of oral pigmented lesions is provided, as well as advice on the application of the ABCDE criteria to standardize recording of oral pigmented lesions.

Association of oral mucosa hyperpigmentation with imatinib mesylate use: a cross-sectional study and a systematic literature review

OBJECTIVES

To assess the association between oral mucosa hyperpigmentation in patients with leukemia and imatinib mesylate use. Additionally, we compared our data to those obtained from a systematic review.

MATERIALS AND METHODS

A cross-sectional study was conducted with 74 patients undergoing treatment with imatinib mesylate. Sociodemographic characteristics, oral mucosa alterations, and medical history were evaluated. Oral hyperpigmentation was scored. The use of imatinib mesylate and hydroxyurea was evaluated. Association between oral hyperpigmentation and imatinib mesylate was assessed. A systematic review was also conducted to retrieve case reports or case series of patients with oral hyperpigmentation associated with imatinib mesylate.

RESULTS

Among the 74 participants, 41 were male (55.4%) and 33 were female (44.6%). Participants' mean age was 49.3 years. Sixty-six (89.2%) patients developed hyperpigmented lesions in the hard palate mucosa. In multivariate analysis, patients who had used imatinib mesylate for > 72 months had a hyperpigmentation score 1.62 times higher than those who had used this medication during a shorter period. Patients who had used hydroxyurea for > 30 days had a hyperpigmentation score 1.43 times higher than those who had used this medication during a shorter period. The systematic review retrieved 20 clinical cases of patients undergoing imatinib mesylate treatment and exhibiting oral hyperpigmentation.

CONCLUSIONS

The development of oral hyperpigmentation is associated with imatinib mesylate use. Hydroxyurea seems to increment such an association.

CLINICAL RELEVANCE

To assist providers in the differential diagnosis of hyperpigmented lesions associated with imatinib mesylate, as well as in the clinical management of such lesions.

5-year survival rates based on the type of leukemia in Iran, a Meta-analysis

Background:

According to epidemiological studies, leukemia is among the five most common cancers in Iran. Keeping efforts to estimate survival is critical to monitoring and improving patients’ quality of life with leukemia. The purpose of this study was to evaluate the 5-year survival rate of leukemia patients in Iran using meta-analysis method.

Methods:

This meta-analysis was carried out according to studies that adhere to inclusion and exclusion criteria during enrolment. The valid Iranian databases included: Medex, Magiran, SID, and Medlib, along with international data bases, namely, Scopus, Pubmed, and ISI were searched to find relevant articles. After determining the heterogeneity between studies, the random effects models were used to estimate pooled survival in leukemia patients.

Results:

In total, 18 studies involving 2517 participants were included in this meta-analysis. The pooled 5-year survival rate was 0.56 % (95% CI, 0.54 to 0.58). According to types AML and ALL, the 5-year survival rates in Iran were 35.0 % (95% CI: 32.0-38.0) and 57.0 % (95% CI: 54.0-60.0), respectively.

Conclusion:

Based on our findings, slightly less than 50% of leukemia deaths happened in the first 5 years after diagnosis, which is lower than the global average.

Use patterns of first-line inhibitors of tyrosine kinase and time to change to second-line therapy in chronic myeloid leukemia

Background Chronic myeloid leukemia (CML) has a low incidence but a high burden of disease, and is treated with high-cost tyrosine kinase inhibitors (TKI). Objective To determine the time from the start of a first-line TKI until it passes to second-line, and to establish the reasons for the change of therapy time. Setting Patients with Philadelphia-positive CML treated with some TKI. Methods Retrospective cohort study, between January 1 2007 and July 31 2015, with information obtained from medical records, the time to change initial drugs to secondline therapy, and the reasons for change, were identified. Kaplan-Meier survival analysis was carried out. Main outcome measure A change in therapy to the secondline TKI and the final reason for the change of therapy. Results A total of 247 patients treated were found in 22 cities in Colombia with a mean age of 53.2 ± 15.2 years. The drug most used as initial therapy was imatinib; 53.8% of cases had to change to another TKI. 50% of patients changed therapy in 42 months, men in 24 and women in 67 months (95% CI 14.314-33.686; p = 0.001). Being male (OR 2.23; 95% CI 1.291-3.854; p = 0.004) and receiving hydroxyurea (OR 3.65; 95% CI 1.601-8.326; p = 0.002) were associated with a higher probability of switching to nilotinib or dasatinib, while receiving a new-generation TKI (OR 0.15; 95% CI 0.071-0.341; p < 0.001) reduced this risk. Conclusions A high proportion of patients needed to change to a second line with nilotinib and dasatinib management. It is necessary to obtain more real world evidence, to improve the effectiveness, adherence and safety of the treatment.

Diagnosis and Monitoring of Chronic Myeloid Leukemia: Chiang Mai University Experience

BACKGROUND

A diagnosis of chronic myeloid leukemia (CML) is made on discovery of the presence of a Philadelphia (Ph) chromosome. The success of the treatment of this form of leukemia with tyrosine kinase inhibitor (TKI) is monitored by reduction of the Ph chromosome.

OBJECTIVE

To compare the role of conventional cytogenetic (CC) methods with a real time quantitative polymerase chain reaction (RQ-PCR) and fluorescence in situ hybridization (FISH) for diagnosis and treatment monitoring of CML patients. The secondary outcome was to analyze the treatment responses to TKI in CML patients.

MATERIALS AND METHODS

This was a retrospective study of CML patients who attended the Hematology clinic at Chiang Mai University Hospital from 2005-2010. Medical records were reviewed for demographic data, risk score, treatment response and the results of CC methods, FISH and RQ-PCR.

RESULTS

One hundred and twenty three cases were included in the study, 57.7% of whom were male with a mean age of 46.9 years. Most of the patients registered as intermediate to high risk on the Sokal score. At diagnosis, 121 patients were tested using the CC method and 118 (95.9%) were identified as positive. Five patients failed to be diagnosed by CC methods but were positive for BCR-ABL1 using the FISH method. Imatinib was the first-line treatment used in 120 patients (97.6%). In most patients (108 out of 122, 88.5%), a complete cytogenetic response (CCyR) was achieved after TKI therapy and in 86 patients (70.5%) CCyR was achieved long term by the CC method. Five out of the 35 analyzed patients in which CCyR was achieved by the CC method had a positive FISH result. Out of the 76 patients in which CCyR was achieved, RQ-PCR classified patients to only CCyR in 17 patients (22.4%) with a deeper major molecular response (MMR) in 4 patients (5.3%) and complete molecular response (CMR) in 55 patients (72.4%). In the case of initial therapy, CCyR was achieved in 95 patients (79.1%) who received imatinib and in both patients who received dasatinib (100%). For the second line treatment, nilotinib were used in 30 patients and in 19 of them (63.3%) CCyR was achieved. In half of the 6 patients (50%) who received dasatinib as second line or third line treatment CCyR was also achieved.

CONCLUSIONS

CML patients had a good response to TKI treatment. FISH could be useful for diagnosis in cases where CC analysis failed to detect the Ph chromosome. RQ-PCR was helpful in detecting any residual disease and determining the depth of the treatment response at levels greater than the CC methods.

Anti-Proliferative Effects of Dendrophthoe pentandra Methanol Extract on BCR/ABL-Positive and Imatinib-Resistant Leukemia Cell Lines

Background:

Imatinib mesylate, a tyrosine kinase inhibitor specifically targeting the BCR/ABL fusion protein, induces hematological remission in patients with chronic myeloid leukemia (CML). However, the majority of CML patients treated with imatinib develop resistance with prolonged therapy. Dendrophthoe pentandra (L.) Miq. is a Malaysian mistletoe species that has been used as a traditional treatment for several ailments such as smallpox, ulcers, and cancers.

Methods:

We developed a resistant cell line (designated as K562R) by long-term co-culture of a BCR/ABL positive CML cell line, K562, with imatinib mesylate. We then investigated the anti-proliferative effects of D. pentandra methanol extract on parental K562 and resistant K562R cells. Trypan blue exclusion assays were performed to determine the IC50 concentration; apoptosis and cell cycle analysis were conducted by flow cytometry.

Results:

D. pentandra extract had greater anti-proliferative effects towards K562R (IC50= 192 μg/mL) compared to K562 (500 μg/mL) cells. Upon treatment with D. pentandra extract at the IC50 concentration: K562 but not K562R demonstrated increase in apoptosis and cell cycle arrest in the G2/M phase.

Conclusion:

D. pentandra methanol extract exerts potent anti-proliferative effect on BCR/ABL positive K562 cells.