Cerebrospinal fluid penetrance of lenalidomide in meningeal myeloma

Relapsed refractory multiple myeloma with CNS involvement successfully treated with Elranatamab: first reported case

Central nervous system (CNS) involvement in multiple myeloma (MM) is a rare and challenging complication associated with poor prognosis and limited treatment options. Emerging T-cell directing therapies, such as bispecific antibodies (bsAbs) and chimeric antigen receptor T cells (CAR-T), have shown remarkable success in treating MM, but their efficacy in CNS involvement remains unclear. Elranatamab, a humanized bispecific antibody targeting B-cell maturation antigen (BCMA) and CD3-expressing T cells, has demonstrated promising results in relapsed refractory MM. However, its efficacy in treating CNS-MM has not been reported. We present a case of a 37-year-old male MM patient with CNS involvement who has been successfully treated with Elranatamab.

Efficacy and safety of lenalidomide in HIV-associated cryptococcal meningitis patients with persistent intracranial inflammation: an open-label, single-arm, prospective interventional study

BACKGROUND

Patients with human immunodeficiency virus-associated cryptococcal meningitis (HIV-CM) have persistent intracranial inflammation despite negative cerebrospinal fluid (CSF) fungal cultures after optimal treatment for CM, which could be devastating for the central nervous system. However, a definitive treatment strategy for persistent intracranial inflammation despite optimal antifungal therapies is undefined.

METHODS

We identified 14 HIV-CM patients with persistent intracranial inflammation and conducted a 24-week, prospective, interventional study. All participants received lenalidomide (25 mg, p.o.) on days 1 to 21 of a 28-day cycle. Follow-up lasted for 24 weeks with visits at baseline and weeks 4, 8, 12, and 24. The primary endpoint was the change in clinical manifestations, routine CSF parameters, and MRI findings after lenalidomide treatment. An exploratory analysis was made on changes in cytokine levels in CSF. Safety and efficacy analyses were undertaken in patients who received at least one dose of lenalidomide.

RESULTS

Of 14 participants, 11 patients completed the 24 weeks of follow-up. Rapid clinical remission following lenalidomide therapy was observed. Clinical manifestations (fever, headache, altered mentation) were reversed fully by week-4 and remained stable during follow-up. A significant reduction in white blood cell (WBC) count in CSF was noted occurred at week-4 (P = 0.009). The median protein concentration in CSF decreased from 1.4 (0.7-3.2) g/L at baseline to 0.9 (0.6-1.4) at week-4 (P = 0.004). The median albumin concentration in CSF decreased from 79.2 (48.4-149.8) mg/L at baseline to 55.3 (38.3-89.0) mg/L at week-4 (P = 0.011). The WBC count, protein level, and albumin level in CSF remained stable and approached a normal range through week-24. There was no significant change in immunoglobulin-G, intracranial pressure (ICP), or chloride-ion concentration at each visit. Brain MRI demonstrated multiple lesions to be absorbed post-therapy. Levels of tumor necrosis factor-α granulocyte colony stimulating factor, interleukin (IL)-6, and IL-17A decreased significantly during 24-week follow-up. Two (14.3%) patients had mild skin rash, which resolved spontaneously. Lenalidomide-related serious adverse events were not observed.

CONCLUSION

Lenalidomide could improve persistent intracranial inflammation in HIV-CM patients significantly and was well tolerated without serious adverse events observed. And the additional randomized controlled study is required to further validate the finding.

Central Nervous System Myeloma and Unusual Extramedullary Localizations: Real Life Practical Guidance

Central nervous system localization of multiple myeloma (CNS-MM) accounts for about 1% of all MM during disease course or even rarer at diagnosis. A difference in the origin, i.e., osteodural or primary dural vs leptomeningeal/intraparenchymal, seems to define two distinct types of intracranial myeloma, with different clinical behavior. CNS-MM may occur also as a presentation of MM. Treatment is still unsatisfactory and many treatments have been reported: chemotherapy, intrathecal therapy, and radiotherapy, with dismal prognosis. Other sites of myeloma localization could be also of interest and deserve description. Because of the rarity and aggressiveness of the disease clinicians are often doubtful on how to treat it since there is no general agreement. Moreover, recent drugs such as the anti CD38 monoclonal antibody, immunomodulatory drugs, and proteasome inhibitors have changed the treatment of patients with MM with a significant improvement in overall response and survival. The role of novel agents in CNS MM management and unusual presentations will be discussed as well as the potential role of other new immunomodulatory drugs and proteasome inhibitors that seem to cross the blood-brain barrier. The purpose of this review is to increase awareness of the clinical unusual presentation and neuroradiological findings, give practical diagnostic advice and treatment options algorithm.

Low cerebrospinal fluid-to-plasma ratios of orally administered lenalidomide mediated by its low cell membrane permeability in patients with hematologic malignancies

Lenalidomide is a synthetic analog of thalidomide formed by the removal of one keto group (plus the addition of an amino group); it has anti-tumor activities beneficial for the treatment of hematologic malignancies. However, lenalidomide distribution to brain in animal models is reportedly low compared with that of thalidomide. The aim of this study was to evaluate plasma and cerebrospinal fluid concentrations of lenalidomide in three patients with malignant hematologic malignancies. Lenalidomide was detected in plasma from the three Japanese patients 1.5 h following oral administration of 20 mg lenalidomide using liquid chromatography/mass spectrometry, despite the in vitro gastrointestinal permeability of lenalidomide being low. Clinically observed cerebrospinal fluid-to-plasma ratios of lenalidomide were low (1.3-2.4%). Observed influx permeability values for lenalidomide in monkey blood-brain barrier model and human placental cell systems were one order of magnitude lower than those of thalidomide and another second-generation drug, pomalidomide along with a positive permeability control, caffeine. Because of the low cell-barrier permeability of lenalidomide demonstrated in in vitro assays, clinically relevant pharmacokinetic profiles of lenalidomide resulted in low penetrability from plasma into cerebrospinal fluid in patients with hematologic malignancies. Lenalidomide is conclusively suggested to expert its favorable immunomodulatory effects via systemic exposures in the patients.

Secondary CNS myeloma with remission after systemic CNS-penetrating agents

Background

CNS myeloma is a rare manifestation of multiple myeloma and is often associated with a dismal prognosis; however, cases are increasing in frequency as overall survival improves for MM. There is currently no standardized treatment for CNS myeloma; however, different chemotherapy and radiotherapy regimens have been described.

Methods

We had previously reported on the efficacy of proton-based craniospinal irradiation in a patient with CNS myeloma; here we present a patient with a history of extramedullary plasmacytoma, 10 years in remission status post standard systemic chemotherapy, with biopsy-proven CNS myeloma successfully treated with systemic chemotherapy as a first-line treatment.

Results

The patient achieved clinical and radiographic remission on 2 separate occasions with systemic chemotherapy alone.

Conclusions

This case demonstrates that systemically administered agents may have activity in CNS myeloma. Further investigations are necessary to establish the optimal combination of agents and treatment schedules.

A nationwide survey on central nervous system multiple myeloma in Japan: analysis of prognostic and treatment factors that impact survival

This nationwide multicentre retrospective study was performed to analyze clinical features that predict the prognosis of central nervous system invasion in multiple myeloma (CNS-MM, approximately 1% of MM). Overall, of the 77 adult patients with CNS-MM identified between 2005 and 2016, those diagnosed at MM diagnosis (n = 3) had longer overall survival (OS) than those diagnosed at relapse (n = 74; median: 48·5 vs 2·7 months). Therefore, we compared the relapsed MM with CNS-MM in patients with any treatment (n = 60). Multivariate analyses revealed that lenalidomide treatment [hazard ratio (HR) 0·27, P = 0·003], intrathecal chemotherapy (IT; HR 0·54, P = 0·05), and radiation therapy (RTx; HR 0·33, P < 0·001) for CNS-MM had a positive effect on longer OS. These factors were used to develop a scoring system combining the number of treatments with lenalidomide, IT, and RTx (0, 1, 2, 3). The OS of CNS-MM patients was stratified based on these factors, with a median OS of 1·1, 4·5, and 7·5 months for patients with zero, one, two to three favourable features, respectively (0 vs 1, P = 0·0002; 1 vs 2-3, P = 0·08). Multimodal treatment including lenalidomide in addition to conventional IT and RTx can improve OS.

Multiple Myeloma with Central Nervous System Relapse Early after Autologous Stem Cell Transplantation: A Case Report and Literature Review

Few reports have so far described central nervous system (CNS) involvement in multiple myeloma (MM), which shows a poor prognosis owing to its resistance to several treatments. We herein describe a 45-year-old woman who had MM (diagnosed with IgA-κ type) with CNS relapse early after undergoing autologous hematopoietic stem cell transplantation. Because no standard treatment for CNS lesions of MM has been established, we conducted a literature review on the cerebrospinal fluid (CSF) transferability of drugs for MM, since it was considered to be a useful tool for CNS involvement. Immunomodulatory-drugs including pomalidomide exhibit a good CSF transfer ability, and, therefore, may be beneficial against the CNS involvement of MM.

Aggressive Central Nervous System Relapse after Autologous Stem Cell Transplant in Multiple Myeloma: Case Reports and Literature Review

Extramedullary disease is an aggressive presentation at diagnosis and relapse for multiple myeloma (MM) patients. Central nervous system (CNS) is a very rare manifestation of the extramedullary disease, accounting for less than 1% of MM on diagnosis and relapse. Neurological symptoms are unspecific and usually attributed to other causes. We present two patients with CNS-MM at relapse after autologous stem cell transplant highlighting the importance of clinical suspicion and interdisciplinarity at diagnostic workup as well as the need for intensive therapeutic options on such rare and aggressive cases. The presence of neurological abnormalities in anamnesis and physical examination on a patient with MM should always prompt to suspect of a CNS involvement, and active investigation must be undertaken. MRI is the standard radiological method to detect CNS-MM, with histopathological corroboration by stereotactic biopsy and CSF evaluation alongside. Treatment of CNS-MM should include two essential approaches—be able to cross the BBB and treat the systemic disease. There is no standard therapy for this extramedullary relapse, and a tailored and multiple therapy should be promptly started—intrathecal therapy, radiotherapy, and systemic therapy, including an immunomodulator.

Development of a physiologically based pharmacokinetic model for intravenous lenalidomide in mice

PURPOSE

Lenalidomide is used widely in B-cell malignancies for its immunomodulatory activity. It is primarily eliminated via the kidneys, with a significant proportion of renal elimination attributed to active processes. Lenalidomide is a weak substrate of P-glycoprotein (P-gp), though it is unclear whether P-gp is solely responsible for lenalidomide transport. This study aimed to determine whether the current knowledge of lenalidomide was sufficient to describe the pharmacokinetics of lenalidomide in multiple tissues.

METHODS

A physiologically based pharmacokinetic model was developed using the Open Systems Pharmacology Suite to explore the pharmacokinetics of lenalidomide in a variety of tissues. Data were available for mice dosed intravenously at 0.5, 1.5, 5, and 10 mg/kg, with concentrations measured in plasma, brain, heart, kidney, liver, lung, muscle, and spleen. P-gp expression and activity were sourced from the literature.

RESULTS

The model predictions in plasma, liver, and lung were representative of the observed data (median prediction error 13%, - 10%, and 30%, respectively, with 90% confidence intervals including zero), while other tissue predictions showed sufficient similarity to the observed data. Contrary to the data, model predictions for the brain showed no drug reaching brain tissue when P-gp was expressed at the blood-brain barrier. The data were better described by basolateral transporters at the intracellular wall. Local sensitivity analysis showed that transporter activity was the most sensitive parameter in these models for exposure.

CONCLUSION

As P-gp transport at the blood-brain barrier did not explain the observed brain concentrations alone, there may be other transporters involved in lenalidomide disposition.

The possible role of maintenance treatment for primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive brain tumor. The prognosis is poor, with high rates of relapse and disease progression after treatment. In addition, PCNSL affects a largely older population, so that a significant proportion of patients are ineligible for intensive therapies and high-dose chemotherapy. The elderly patients are also susceptible to the accelerated and detrimental cognitive side effects of whole-brain irradiation which is an alternative consolidation to high-dose chemotherapy. Maintenance therapy has been shown to be a promising strategy to prolong remission time in other hematopoietic malignancies. Herein, we discuss the place of maintenance treatment in PCNSL in view of perspective obtained from hematological malignancies and non-Hodgkin's lymphoma.

Clinical Pharmacokinetics and Pharmacodynamics of Lenalidomide

Lenalidomide is a lead therapeutic in multiple myeloma and deletion 5q myelodysplastic syndromes and shows promising activities in other hematologic malignancies. This article presents a comprehensive review of the clinical pharmacokinetics and pharmacodynamics of lenalidomide. Oral lenalidomide is rapidly and highly absorbed (>90 % of dose) under fasting conditions. Food affects oral absorption, reducing area under the concentration-time curve (AUC) by 20 % and maximum concentration (C max) by 50 %. The increase in AUC and C max is dose proportional, and interindividual variability in plasma exposure is low to moderate. Lenalidomide distributes into semen but is undetectable 3 days after stopping treatment. Biotransformation of lenalidomide in humans includes chiral inversion, trivial hydroxylation, and slow non-enzymatic hydrolysis. Approximately 82 % of an oral dose is excreted as lenalidomide in urine within 24 h. Lenalidomide has a short half-life (3-4 h) and does not accumulate in plasma upon repeated dosing. Its pharmacokinetics are consistent across patient populations, regardless of the type of hematologic malignancy. Renal function is the only important factor affecting lenalidomide plasma exposure. Lenalidomide has no QT prolongation risk at approved doses, and higher plasma exposure to lenalidomide is associated with increased risk of neutropenia and thrombocytopenia. Despite being a weak substrate of P-glycoprotein (P-gp) in vitro, lenalidomide does not have clinically significant pharmacokinetic interactions with P-gp substrates/inhibitors in controlled studies. The AUC-matched dose adjustment is recommended for patients with renal impairment at the start of therapy. No dose adjustment for lenalidomide is needed on the basis of age, ethnicity, mild hepatic impairment, or drug-drug interactions.