Chronic Myeloid Leukemia and Pregnancy: When Dreams Meet Reality. State of the Art, Management and Outcome of 41 Cases, Nilotinib Placental Transfer

Perspectives on Drug Development for the Treatment of Chronic Myeloid Leukemia in Pregnant Patients and Patients Who Are Breastfeeding

Tyrosine kinase inhibitors (TKI) have improved the outcome and life expectancy of patients with chronic myeloid leukemia (CML). Patients are diagnosed with CML at younger ages, and patients treated for CML may become pregnant or choose to breastfeed. The information available to date on the safety of TKIs during pregnancy and lactation and the optimal management of these patients is largely anecdotal, based on personal or small-group experience, and heterogeneous. A panel of interested parties was convened by U.S. Food and Drug Administration to analyze the current data and discuss possible solutions. Possible solutions include prospective data collection, in clinical trials and in routine clinical practice, a more uniform and specific data collection, and greater coordination among involved entities. As patients with cancer are living longer, frequently receiving therapies for extended periods of time (or for life), data on appropriate management of patients through different reproductive phases of life are needed. It is thus time to change our approach for how to study treatment of cancer (including CML) during pregnancy or breastfeeding to develop evidence-based guidelines for safe and effective patient care.

SOHO State of the Art Updates and Next Questions: Chronic Myeloid Leukemia and Pregnancy: "Per Aspera Ad Astra"

Chronic myeloid leukemia (CML) has evolved from an invariably fatal disease to a chronic disorder that can be treated with targeted drugs and allows survival expectations approaching age-matched controls. Thus, pregnancy and conception in CML should not be precluded anymore; however, to ensure the well-being of both the mother and the developing fetus careful planning and management are required. Tyrosine Kinase Inhibitors (TKIs) are not genotoxic or carcinogenic but can pose a risk to the developing fetus, due to their teratogenic potential. The risk depends on the TKI and the stage of fetal development during exposure. Teratogenic risk is high in the first trimester of pregnancy when the baby's organs and structures are forming (5-12 weeks). If a female patient is on therapy it is advisable to stop therapy at the first positive pregnancy test (3-5 weeks) to maximize the length of treatment-free, and ideally to not treat until delivery. If needed, the medication plan during pregnancy may be adjusted. Interferons can be used at any time, imatinib and nilotinib have a reduced placental crossing and could be carefully used after 16 weeks, whereas dasatinib crosses the placenta and can induce problems throughout the whole gestation. Management of pregnancy in CML is complex. This manuscript is an update of the state of the art allowing healthcare providers to be informed of the different situations that can occur and their governance.

Chronic myeloid leukemia diagnosed in pregnancy: management and outcome of 87 patients reported to the European LeukemiaNet international registry

The management of chronic myeloid leukemia (CML) diagnosed during pregnancy is a rare and challenging situation. We report the treatment and outcome of 87 cases diagnosed in chronic phase from 2001-2022 derived from the largest international observational registry, supported by the European LeukemiaNet (ELN), of 400 pregnancies in 299 CML women. Normal childbirth occurred in 76% without an increased rate of birth abnormalities or life-threatening events, including in patients untreated or treated with interferon-α and/or imatinib in 2nd-3rd trimester. The low birth weight rate of 12% was comparable to that seen in the normal population. Elective and spontaneous abortions occurred in 21% and 3%, respectively. The complete hematologic response rate before labor was 95% with imatinib and 47% with interferon only. No disease progression during pregnancy was observed, 28% of the patients switched their therapy at varying times after delivery. Treatment options balance the efficacy and safety for mother and infant: interferon-α can commence in the 1st trimester and continued throughout in cases of good disease control and tolerability. Because of limited placental crossing, selected tyrosine kinase inhibitors (imatinib and nilotinib) seem to be safe and effective options in 2nd and 3rd trimester while hydroxycarbamide offers few benefits.

Physiologically Based Pharmacokinetic Modeling of Nilotinib for Drug-Drug Interactions, Pediatric Patients, and Pregnancy and Lactation

Nilotinib is a second-generation BCR-ABL tyrosine kinase inhibitor for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia in both adult and pediatric patients. The pharmacokinetics (PK) of nilotinib in specific populations such as pregnant and lactating people remain poorly understood. Therefore, the objectives of the current study were to develop a physiologically based pharmacokinetic (PBPK) model to predict nilotinib PK in virtual drug-drug interaction (DDI) studies, as well as in pediatric, pregnant, and lactating populations. The nilotinib PBPK model was built in PK-Sim, which is part of the free and open-source software Open Systems Pharmacology. The observed clinical data for the validation of the nilotinib models were obtained from the literature. The model reasonably predicted nilotinib concentrations in the adult population; the DDIs between nilotinib and rifampin or ketoconazole in the adult population; and the PK in the pediatric, pregnant, and lactating populations, although in the latter 2 populations plasma concentrations were slightly underestimated. The ratio of predicted versus observed PK parameters for the adult model ranged from 0.71 to 1.11 for area under the concentration-time curve and 0.55 to 0.95 for maximum concentration. For the DDI, the predicted area under the concentration-time curve ratio and maximum concentration ratio fell within the Guest criterion. The current study demonstrated the utility of using PBPK modeling to understand the mechanistic basis of PK differences between adults and specific populations, such as pediatrics, and pregnant and lactating individuals, indicating that this technology can potentially inform or optimize dosing conditions in specific populations.

Therapeutic drug monitoring of imatinib - how far are we in the leukemia setting?

INTRODUCTION

Tyrosine kinase inhibitors (TKIs) have revolutionized survival rates of chronic myeloid leukemia (CML) and Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) and replaced hematopoietic stem cell transplantation (hSCT) as the key treatment option for these patients. More recently, the so-called Philadelphia chromosome-like (Ph-like) ALL has similarly benefitted from TKIs. However, many patients shift from the first generation TKI, imatinib, due to treatment-related toxicities or lack of treatment efficacy. A more personalized approach to TKI treatment could counteract these challenges and potentially be more cost-effective. Therapeutic drug monitoring (TDM) has led to higher response rates and less treatment-related toxicity in adult CML but is rarely used in ALL or in childhood CML.

AREAS COVERED

This review summarizes different antileukemic treatment indications for TKIs with focus on imatinib and its pharmacokinetic/-dynamic properties as well as opportunities and pitfalls of TDM for imatinib treatment in relation to pharmacogenetics and co-medication for pediatric and adult Ph+/Ph-like leukemias.

EXPERT OPINION

TDM of imatinib adds value to standard monitoring of ABL-class leukemia by uncovering non-adherence and potentially mitigating adverse effects. Clinically implementable pharmacokinetic/-dynamic models adjusted for relevant pharmacogenetics could improve individual dosing. Prospective trials of TDM-based treatments, including both children and adults, are needed.

Fertility and pregnancy in chronic myeloid leukemia: real-world experience from an Indian tertiary care institution

Chronic myeloid leukemia (CML) management during pregnancy is challenging. In this retrospective study, hospital records of CML patients treated between 2000 and 2021 were screened to identify patients who tried to conceive/got pregnant (planned and unplanned) on TKIs (tyrosine kinase inhibitors)/were pregnant at CML onset/fathered a child. We found ninety-three pregnancies involving thirty-three women and thirty-eight men, and they were analyzed for the pregnancy outcomes and the strategies utilized for CML management during pregnancy and the pre-conception period. There were two women and four men with primary infertility and five women with secondary infertility. TKIs were discontinued before conception in four planned pregnancies and at the time of recognition of pregnancy in unplanned pregnancies (n = 21). Unplanned pregnancy outcomes were two miscarriages, eight elective terminations, and eleven live births. Planned pregnancies led to four healthy babies. Outcomes of pregnancies at CML onset (n = 17) were six live births, one stillbirth, five elective terminations, and five abortions. Except for one child with congenital micro-ophthalmia, no other child born to the women on TKI had any malformations. Thirty-eight men fathered 51 healthy children. All but two patients (one planned and one unplanned pregnancy) lost their hematological responses during pregnancy and gained their previous best response after restarting TKI. In women who were pregnant at CML onset, complete cytological remission (CCYR) was achieved between 7 and 24 months (median:14 months) after starting TKI. During pregnancy, intermittent hydroxyurea ± TKI (in the second and third trimesters) was used to keep WBCs less than 30,000/mm3. Outcomes of pregnancies in CML patients can be optimized with our approach. TKIs (Imatinib and Nilotinib) can be safely used in the second and third trimesters. Delayed initiation or interruption of TKI during pregnancy does not negatively affect response to TKIs.

Landscape and Regulatory Perspective on Oncology Drugs in Pregnancy

Cancers affecting pregnant women include breast cancer, melanoma, thyroid cancer, cervical cancer, lymphomas, and leukemias. The medical management of cancer during pregnancy with molecularly targeted oncology drugs remains quite challenging, with knowledge gaps about the drugs' safety and efficacy due to exclusion of pregnant women from cancer clinical trials, discontinuation of individuals who become pregnant during clinical trials, and limited information on appropriate dosing of molecularly targeted oncology drugs during pregnancy. Physiological changes occur during pregnancy and may result in alterations in the absorption, distribution, metabolism, and excretion of drugs used in pregnant women. Physiologically based pharmacokinetic modeling that incorporates physiological changes induced by both the cancer disease state and pregnancy has the potential to inform dosing of molecularly targeted oncology drugs for pregnant women, improve our understanding of the pharmacokinetic changes associated with pregnancy in patients with cancer, facilitate the design of potential studies of molecularly targeted oncology drugs in pregnant women to support dosing recommendations, and provide model-informed pharmacokinetic data to support regulatory decision making.

Acute leukemias in pregnant women: Results of a retrospective study at a local tertiary-care hospital in Japan

Leukemia may rarely develop in a woman during pregnancy, posing clinical challenges to the patient, fetus, family, and medical staff managing malignancy and pregnancy. We retrospectively analyzed cases of pregnancy-associated leukemia consecutively diagnosed and treated at a local tertiary-care hospital in Nagano, Japan, over the past 20 years. Five cases were identified among 377,000 pregnancies in the area (one in every 75,000 pregnancies), all involving acute leukemia (three acute myelogenous leukemia [AML] and two acute lymphoblastic leukemia [ALL]). The cases were diagnosed in the first trimester (n = 1), second trimester (n = 3), or third trimester (n = 1). There were no apparent pregnancy-associated delays in diagnosing and treating the cases. Three patients underwent induction chemotherapy during pregnancy, two of whom eventually delivered healthy babies. One of the five patients chose abortion before chemotherapy initiation. Two cases showing high-risk features at the diagnosis (AML with an FLT3-ITD mutation [n = 1] and relapsed ALL [n = 1]) eventually died despite consolidative allogeneic hematopoietic stem cell transplantation. Our results suggested that patients with pregnancy-associated acute leukemia can be treated similarly to nonpregnant patients, although pregnancy imposes particular clinical challenges that should be resolved with multidisciplinary care.

Treatment of CML in pregnancy

Since the introduction of tyrosine kinase inhibitors (TKIs) at the beginning of the millennium, the outlook for patients with chronic myeloid leukemia (CML) has improved remarkably. As such, the question of life expectancy and survival has become less problematic while quality of life and family planning have become more so. While TKIs are the cornerstone of CML management, their teratogenicity renders them contraindicated during pregnancy. In recent years, patients who satisfy standardized criteria can stop TKI therapy altogether, and indeed, in eligible patients who wish to become pregnant, these objectives overlap. However, not all patients satisfy these criteria. Some pregnancies are unplanned, and a number of patients are pregnant when diagnosed with CML. In these patients the way forward is less clear, and there remains a paucity of good evidence available to guide treatment. In this article, we summarize the relevant literature and provide a framework for clinicians faced with the challenge of managing CML and pregnancy.