Hematologic toxicities of small molecule tyrosine kinase inhibitors

Recent advances in the use of tyrosine kinase inhibitors against thyroid cancer

INTRODUCTION

Oncogenic tyrosine kinases (TK) are enzymes that play a key role in cell growth and proliferation and their mutations can lead to uncontrolled cell growth and development of aggressive cancer. This knowledge has led to the development of new classes of drugs, Tyrosine kinase inhibitors (TKI). They target oncogenic kinases who are associated with advanced radioactive iodine (RAI) refractory TC, which is not able to uptake RAI anymore and/or still grows between consecutive treatments with Iodine 131 (I131).

AREAS COVERED

Since Lenvatinib and Sorafenib approval, several other molecular inhibitors have been studied and then introduced for the treatment of aggressive and refractory thyroid cancer (TC), and, although the development of adverse effects or tumor resistance mechanisms, more and more compounds are still under investigation. The literature search was executed in PubMed and ClinicalTrials.gov to identify relevant articles and clinical trials published until December 2023.

EXPERT OPINION

In the context of clinical trials, driven by the presence of specific molecular mutations or even in the absence of both conditions, systemic therapy TKIs are valuable weapons to be used in patients affected by aggressive forms of TC, waiting for further expansion of the treatment landscape with more efficacious and safer drugs.

Tyrosine kinase inhibitor-induced immune hemolytic anemia; three different drugs in three separate cases

INTRODUCTION

Molecular multitargeted small tyrosine kinase inhibitory (TKI) agents such as axitinib, sunitinib and pazopanib are commonly used in several types of solid tumors. Anemia is not a rare effect of these drugs which may occur at all grades. However, drug-induced immune hemolytic anemia (IHA), a very rare condition is distinctive from other types of anemia with its specific mechanism and management strategy.

CASE REPORTS

We reported three different TKI-induced IHA cases that occurred due to axitinib, sunitinib, and pazopanib, respectively. The first two cases were diagnosed with renal cell carcinoma and the last one was diagnosed with soft tissue sarcoma. They all presented with the characteristic symptoms of anemia and hemolysis. All the cases were detected positive for the complement C3d direct antiglobulin (direct coombs) test.

MANAGEMENT AND OUTCOMES

Discontinuation of the causative drug and 1 mg/kg/day dose of corticosteroid treatment were able to control IHA in all three cases. Excluding the other factors of IHA and an evident laboratory and clinical benefit after withholding the TKI led to the diagnosis of TKI-related IHA in each case.

DISCUSSION

TKIs are relatively new in clinical practice and are being used for more indications and in more patients. To our knowledge#these three cases are unique in terms of axitinib#sunitinib#and pazopanib-related IHA.

Dasatinib Ointment Promotes Healing of Murine Excisional Skin Wound

Dasatinib, a tyrosine kinase inhibitor, has been shown to produce anti-inflammatory activity and impair vascular integrity in vivo, including during skin wound healing, potentially promoting the repair process. Given that dasatinib is a lipophilic small molecule capable of penetrating skin, topical dasatinib might provide benefits in wound healing. In the present study, we investigated the impact of dasatinib ointments in skin wound healing in mice. A full thickness excisional skin wound (4 mm diameter) was generated on the shaved dorsum of eight-week-old C57BL/6 mice. Dasatinib ointment (0.1 or 0.2% w/w) or ointment base was applied twice daily (every 12 h) for 10 days. Elizabethan collars were used to prevent animal licking. The wound size was monitored daily for 14 days. The results showed that dasatinib ointments, particularly 0.1% dasatinib, promoted a 16-23% reduction in wound size (p < 0.05) during day 2 to day 6 postinjury compared to controls. Immunohistochemistry analyses demonstrated a reduction in wound neutrophils (38% reduction, p = 0.04), macrophages (47% reduction, p = 0.005), and tumor necrosis factor-α levels (73% reduction, p < 0.01), together with an induction of vascular leakage-mediated fibrin(ogen) accumulation (2.5-fold increase, p < 0.01) in the wound during day 3 postinjury (an early phase of repair) in 0.1% dasatinib-treated mice relative to control mice. The anti-inflammatory and vascular hyperpermeability activities of dasatinib were associated with an enhanced healing process, including increased keratinocyte proliferation (1.8-fold increase in Ki67+ cells, p < 0.05) and augmented angiogenesis (1.7-fold increase in CD31+ area, p < 0.05), compared to the ointment base-treated group. Following treatment with 0.2% dasatinib ointment, minor wound bleeding and scab reformation were observed during the late phase, which contributed to delayed healing. In conclusion, our data suggest that dasatinib ointment, mainly at 0.1%, promotes the repair process by reducing inflammation and producing a local and temporal vascular leakage, leading to an increase in fibrin(ogen) deposition, re-epithelialization, and angiogenesis. Therefore, topical dasatinib might be a potential novel candidate to facilitate skin wound healing.

Refractory pancytopenia upon initiation of asciminib in tyrosine kinase inhibitor-resistant chronic myeloid leukemia

Asciminib, a "Specifically Targeting the ABL Myristoyl Pocket" inhibitor, is a new drug in the treatment of tyrosine kinase inhibitor (TKI)-resistant chronic myeloid leukemia (CML). Hemocytopenias associated with asciminib are common adverse events documented by clinical trials. We report a case of precipitous-onset pancytopenia with the initiation of asciminib treatment in a patient with TKI-resistant CML. This case had a confounding array of laboratory findings that evidenced a drug-induced hemophagocytic component. We hope that our case stimulates further reporting of similar cases to enhance the understanding of the pathophysiology underlying asciminib-induced hemocytopenias.

Adjuvant therapy with toceranib for hepatocellular carcinoma and cholangiocarcinoma in a Pomeranian

A 10-year-old spayed female Pomeranian dog was referred for hepatic mass evaluation. Blood tests revealed mildly elevated alkaline phosphatase activities. Computed tomography revealed a mass with multiple nodules on the right hepatic medial lobe adjacent to the caudal vena cava; histopathology confirmed mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). Because of incomplete resection, adjuvant therapy was recommended. As tumour cells showed PDGFR-α, c-Kit, and FGFR1 overexpression, the anticancer effect of tyrosine kinase inhibitors was evaluated on the cells; toceranib was the most effective and was administered starting with an extra-labelled dose. The dog remained stable for 2.3 years with mild adverse effects. To our knowledge, this is the first successful clinical application of toceranib in a dog with mixed HCC-CC.

The effects of cannabidiol via TRPV2 channel in chronic myeloid leukemia cells and its combination with imatinib

Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by accumulation of immature cells in bone marrow and peripheral blood. Although successful results were obtained with tyrosine kinase inhibitors, several patients showed resistance. For this reason, the identification of new strategies and therapeutic biomarkers represents an attractive goal. The role of transient receptor potential (TRP) ion channels as possible drug targets has been elucidated in different types of cancer. Among natural compounds known to activate TRPs, cannabidiol (CBD) displays anticancer properties. By using FACS analysis, confocal microscopy, gene silencing, and cell growth assay, we demonstrated that CBD, through TRPV2, inhibits cell proliferation and cell cycle in CML cells. It promoted mitochondria dysfunction and mitophagy as shown by mitochondrial mass reduction and up‐regulation of several mitophagy markers. These effects were associated with changes in the expression of octamer‐binding transcription factor 4 and PU.1 markers regulated during cellular differentiation. Interestingly, a synergistic effect by combining CBD with the standard drug imatinib was found and imatinib‐resistant cells remain susceptible to CBD effects. Therefore, the targeting of TRPV2 by using CBD, through the activation of mitophagy and the reduction in stemness, could be a promising strategy to enhance conventional therapy and improve the prognosis of CML patients.

Management of Apatinib-Related Adverse Events in Patients With Advanced Osteosarcoma From Four Prospective Trials: Chinese Sarcoma Study Group Experience

Four prospective trials have reported apatinib-related efficacy in osteosarcoma, with a high response rate of 43.2%. Currently, Adverse Events (AEs) have increasingly gained attention, as treatment with multiple tyrosine kinase inhibitors (TKIs) is potentially lifelong. For this reason, a consensus meeting of the Chinese Sarcoma Study Group (CSSG), which is a multidisciplinary panel composed of pediatric, medical and surgical oncologists specializing in sarcoma, nurse specialists, oncological senior pharmacists and gastroenterologists, was held to develop comprehensive guidelines on AEs emerging due to apatinib treatment to better assist in the prevention, management, and understanding of AE development. We summarized all AEs that arose in ≥10% of the participants as well as rare AEs that required extra caution to prevent that were observed in these four published prospective trials and arranged these AEs into 14 disorder systems according to CTCAE 5.0. In this review, we discuss strategies for the management of AEs in patients with advanced osteosarcoma, with the aim of maximizing treatment benefits and minimizing the need for apatinib treatment discontinuation. We also focus on providing recommendations for the prophylaxis and treatment of advanced osteosarcoma using apatinib to achieve optimal outcomes.

Cytopenia among CML Patients on Imatinib in Kenya: Types, Grades, and Time Course

Background

Imatinib mesylate is the gold standard for the treatment of all phases of Philadelphia-positive chronic myeloid leukemia. Patients on imatinib treatment may develop cytopenia due to drug toxicity. This study aimed to determine the types, grades, and time course of cytopenia in CML patients on imatinib at a Nairobi hospital.

Methods

This was a cross-sectional descriptive study of adult patients aged ≥18 years followed up at the Glivec International Patient Access Program (GIPAP) clinic from 2007 to 2015. Patients who developed cytopenia within 12 months of initiating imatinib were eligible. Clinical and hematologic data were retrieved from the patients' charts and entered into a study proforma. Measures of central tendency such as mean, median, mode, standard deviation, and variance were used for analysis.

Results

Sixty three percent (63.6%) of the 94 patients developed a monocytopenia, with anemia seen in 34%, neutropenia in 27.6%, and thrombocytopenia in 8% of the 94 patients. Anemia plus neutropenia was the most common bicytopenia at 12.7%. Pancytopenia was seen in only 5 of the 94 patients. Most of the cytopenia was grades 2 and 3. Anemia was present at baseline while neutropenia and thrombocytopenia developed within 12 months of imatinib initiation. Anemia resolved during the first 12 months of therapy while neutropenia and thrombocytopenia resolved within 24–36 months of treatment.

Conclusion

Monocytopenia, especially anemia, was the most common type of cytopenia. The cytopenia was predominantly grade 2, developed in majority of the patients within 6 months after imatinib initiation, and had resolved by 24–36 months after imatinib initiation.

Haematological adverse events associated with tyrosine kinase inhibitors in chronic myeloid leukaemia: A network meta-analysis

AIMS

Despite their overall favourable safety profile, tyrosine kinase inhibitors (TKIs) are related to severe adverse events including haematological toxicities such as anaemia, leucopenia, neutropenia and thrombocytopenia. We designed a systematic review and network meta-analysis of randomised controlled trials to compare safety among TKIs (bosutinib, dasatinib, imatinib, nilotinib, ponatinib and radotinib) used by patients diagnosed with chronic myeloid leukaemia.

METHODS

We obtained data from the PubMed, Scopus, Web of Science, and SciELO databases. The Bayesian approach was used for direct and indirect comparisons, and the treatments were ranked by the surface under the cumulative ranking curve (SUCRA).

RESULTS

Seventeen studies were included in the network meta-analysis. Our data show that dasatinib was generally considered worse than the other TKIs, with SUCRA values ​​for 140 mg dasatinib of 90.3% for anaemia, 87.4% for leucopenia, 90.6% for neutropenia and 97.2% for thrombocytopenia. In addition, nilotinib was shown to be safer, with SUCRA values ​​for 600 and 800 mg doses of 21.9 and 35.8% for anaemia, 23.8 and 14.6% for leucopenia, 33.0 and 17.7% for neutropenia, and 28.7 and 32.6% for thrombocytopenia, respectively.

CONCLUSION

Dasatinib appeared as the least safe drug for chronic myeloid leukaemia, probably because it binds to multiple key kinase targets, being more prone to cause serious haematological adverse events. Nilotinib demonstrated a safer profile, mostly due to its selective binding capacity.

Macrocytosis during sunitinib treatment predicts progression-free survival in patients with metastatic renal cell carcinoma

Sunitinib, a multi-targeted receptor tyrosine kinase inhibitor, is a first-line treatment for metastatic renal cell carcinoma (mRCC) in patients in ‘low’ and ‘intermediate’ Memorial Sloan Kettering Cancer Center and Heng risk groups. Disruptions of hematopoiesis, such as anemia, neutropenia, and thrombocytopenia, are typically observed during sunitinib treatment. When it comes to RBC parameters, an increase in mean cell volume (MCV) tends to occur, meeting the criteria for macrocytosis in some patients (MCV > 100 fL). We examined changes in RBC parameters of 27 mRCC patients treated with sunitinib (initial dose of 50 mg/day, 6-week treatment: 4 weeks on, 2 weeks off) and correlated them with progression-free survival time (PFS). Patients who had macrocytosis after 3 treatment cycles had significantly longer PFS than those whose MCV stayed less than 100 fL (not reached vs. 11.2 months, p < 0.001). We also found a correlation between MCV values after the first and third treatment cycles and the risk of progression: HR of 0.9 (0.81–0.99) and 0.76 (0.65–0.90) per 1 fL increase in MCV, respectively. The mechanism of MCV elevation during sunitinib treatment has not yet been fully explained. One of the probable causes is sunitinib’s inhibitory influence on c-Kit kinase, as is the case with imatinib. For mRCC patients, this phenomenon could help predict PFS, but since our sample was small, further studies are essential.

Macrocytosis as a potential parameter associated with survival after tyrosine kinase inhibitor treatment

AIM OF THE STUDY

As a rise in mean corpuscular volume (MCV) of the erythrocyte is frequently seen during treatment with imatinib and sunitinib, we investigated whether macrocytosis (MCV > 100 fl) also occurs as a class effect in other tyrosine kinase inhibitors (TKIs) and whether occurrence of macrocytosis is associated with outcome.

MATERIALS AND METHODS

In 533 patients, using 5 TKIs, we investigated if macrocytosis and an increase in MCV were associated with progression-free survival and overall survival (OS) in specific tumour-treatment combinations.

RESULTS

Macrocytosis as well as an increase in MCV from baseline of >10 fl (ΔMCV +10 fl), when included as a time-dependent covariate, were associated with improved OS in patients with renal cell cancer (RCC) treated with sunitinib (macrocytosis, hazard ratio [HR] = 0.61, p = 0.031, and ΔMCV +10 fl, HR = 0.58, p = 0.016).

CONCLUSION

In sunitinib-treated patients with RCC, the occurrence of macrocytosis, or a substantial increase in MCV levels after start of treatment, could potentially serve as a positive prognostic factor for survival, if validated prospectively.

Kinase inhibitors and monoclonal antibodies in oncology: clinical implications

Molecularly targeted cancer therapies, such as small-molecule kinase inhibitors and monoclonal antibodies, constitute a rapidly growing and an important part of the oncology armamentarium. Unlike conventional (cytotoxic) chemotherapeutics, targeted therapies were designed to disrupt cancer cell pathogenesis at specific biological points essential for the development and progression of the tumour. These agents were developed to disrupt specific targets with the aim of minimizing treatment burden compared with conventional chemotherapy. Nevertheless the increasingly common use of targeted therapies has revealed some unanticipated, often clinically significant toxic effects, as well as compromising effective palliative and end-of-life management approaches. Although patients and clinicians welcome improvements in cancer prognosis, these changes can also impact patient quality-of-life. Therefore, as demand for oncology expertise increases, physicians need to apprise themselves of targeted therapies and their clinical implications, including drug-specific side effects, impact on quality of life, and cost issues, especially in relation to end-of-life care. This Review provides a useful summary and guide for professionals treating patients with malignant diseases.