Meclofenamate + Temozolomide

The combination of meclofenamate and temozolomide is being investigated as a potential treatment for glioblastoma, particularly for recurrent MGMT-methylated glioblastoma. This combination therapy is currently being studied in the MecMeth/NOA-24 clinical trial. ## Background Glioblastoma is the most frequent and malignant primary brain tumor. Even in patients with O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation who initially respond well to first-line therapy, survival after relapse is short, averaging around 12 months[1]. Standard therapy for recurrent MGMT-methylated glioblastoma is not standardized and may include re-resection, re-irradiation, and chemotherapy with temozolomide (TMZ), lomustine (CCNU), or combinations[1]. ## Mechanism of Action Meclofenamate (MFA), originally developed as a nonsteroidal anti-inflammatory drug (NSAID), has shown promise in sensitizing glioblastoma cells to temozolomide-induced toxicity[1][4]. It works through: 1. Inhibition of gap junction-mediated intercellular cytosolic traffic 2. Disruption of tumor microtube (TM)-based network morphology 3. Inhibition of connexin43[4][5] Temozolomide is a prodrug of the imidazotetrazine class that requires nonenzymatic hydrolysis at physiological pH to perform alkylation of adenine/guanine residues, leading to DNA damage through futile repair cycles and eventual cell death[7]. ## Clinical Development The MecMeth/NOA-24 trial is investigating this combination therapy in patients with first relapse of MGMT-methylated glioblastoma[1][2][4]. The trial has: - A Phase I component (6-14 patients, 2 dose levels of MFA + standard dose TMZ) to evaluate safety and feasibility and determine the optimal MFA dose - A randomized Phase II component (2 × 30 patients) with progression-free survival as the primary endpoint[1][4][5] The trial is being conducted in Germany with Pr Ulrich Herrlinger as the principal investigator at the Universitätsklinikum Bonn[2]. ## Dosing Information In the trial, meclofenamate is administered orally in addition to standard temozolomide dosing: - Temozolomide: 150-200 mg/m²/day on days 1-5 of a 28-day cycle - Meclofenamate: Dosage ranges from 100mg to 400mg daily divided into two doses[4][5] The treatment duration is 224 days or until tumor progression, whichever occurs first[5]. ## Preclinical Evidence Preclinical studies have shown that meclofenamate sensitizes glioblastoma cells to temozolomide-induced toxicity[4][5]. Research has also explored other NSAID combinations with temozolomide, including diclofenac, aspirin, ibuprofen, ketoprofen, naproxen, and oxaproxin, which have shown potential synergistic or additive effects against glioblastoma cell lines[6]. This combination represents a promising approach for improving outcomes in patients with recurrent MGMT-methylated glioblastoma, a condition with limited effective treatment options.