It has been proved that intrathecal chemotherapy is the main treatment strategy for leptomeningeal metastases. At present, the commonly used drugs for intrathecal chemotherapy include methotrexate, cytarabine, and liposomal cytarabine. In recent decades, no new effective drugs have been discovered for intrathecal chemotherapy. The recurrence of leptomeningeal metastases is inevitable even after aggressive treatment. There is no effective treatment for recurrent leptomeningeal metastases after comprehensive treatment which includes intrathecal methotrexate and/or cytarabine, central nervous system radiation therapy, systemic chemotherapy as well as tyrosine-kinase inhibitor drugs. The quality of life is extremely poor, and the patients always die in short time. Pemetrexed is a newer multitargeted antifolate which has shown activity in various tumors. It has higher effectiveness and safety, which has been used as the first-line treatment of non-small cell lung cancer. In animal studies, pemetrexed was demonstrated to suppress tumor growth completely in mice with two types of transplanted human colon xenografts resistant to methotrexate. Therefore, the purpose of the study is to evaluate the safety and feasibility of intrathecal pemetrexed in patients with recurrent leptomeningeal metastases from non-small cell lung cancer.
This is a single arm clinical trial. The objective of the study is patients with recurrent or progressive leptomeningeal metastases from non-small cell lung cancer after leptomeningeal metastases-related treatment. The regimen of pemetrexed (Alimta, Eli Lilly and Company) is 10/15/20 mg, plus dexamethasone 5 mg, twice per week for 2 weeks, followed by once per week for 2-4 weeks. Pemetrexed and dexamethasone are administrated by intrathecal injection via lumbar puncture. Folic acid and vitamin B12 are administered to reduce the frequency of myelosuppression. Folic acid 200-400 μg is administered orally once daily, prior to the first intrathecal pemetrexed, until 21 days after the last intrathecal pemetrexed. A single dose of vitamin B12 1000 μg is administered by intramuscular injection before the first intrathecal pemetrexed,once per 3 weeks. To detect the pharmacokinetics of intrathecal pemetrexed, the serum and cerebrospinal fluid samples are collected. These samples would be analyzed by spectrometer for drug concentration.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
13
Pemetrexed,10-15 mg, intrathecal injection via lumbar puncture, twice per week for 2 weeks, followed by once per week for 2-4 weeks.
Dexamethasone, 5 mg, intrathecal injection via lumbar puncture, simultaneously with pemetrexed, twice per week for 2 weeks, followed by once per week for 2-4 weeks.
Folic acid, 400 μg, oral, once per day, prior to the first intrathecal pemetrexed, until 21 days after the last intrathecal pemetrexed.
A single dose of vitamin B12 1000 μg, intramuscular injection, before the first intrathecal pemetrexed.
The First Hospital of Jilin University
Changchun, Jilin, China
Incidence of severe adverse events
Adverse events (AEs) are evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE, version 3.0). Events of grade 3-5 are defined as moderate and severe adverse events.
Time frame: Two months after the treatment.
Maximal tolerated dose
A dose-limiting toxicity (DLT) was defined as grade 3 neurological toxicities (e.g. chemical meningitis) or other grade 4 toxicity. If more than two patients experienced a DLT, that level was considered too toxic. The maximal tolerated dose (MTD) was exceeded and an additional three patients should be treated at the next lower dose level. The MTD was defined as the dose where 0/3 or 1/6 patients experienced a DLT with at least two patients encountering DLT at the higher dose.
Time frame: From the beginning of the treatment until two months after the treatment.
Clinical response rate
The RANO proposal for response criteria of leptomeningeal metastasis was used to assess the clinical response in this study.
Time frame: One month after the treatment.
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