Multitargeted Antifolate Research Articles

Phase II study of first-line LY231514 (multi-targeted antifolate) in patients with locally advanced or metastatic colorectal cancer: An NCIC Clinical Trials Group study

Metastatic colon cancer is difficult to treat with treatment being palliative and with little effect on survival. This trial has evaluated the effects of LY231514 (Multitargeted antifolate (MTA)) given to previously untreated patients with recurrent or metastatic colorectal carcinoma. All patients were required to have a histological diagnosis of colorectal adenocarcinoma with measurable disease and no prior chemotherapy for metastatic disease. Patients had to have had performance status of 0-2, pretreatment absolute granulocyte count of > or = 1.5 x 10(9)/l and a platelet count of > or = 150 x 10(9)l. Patients received MTA at a dose of 600 mg/m2 by 10 minute infusion on day 1 repeated every 21 days. After the first 9 patients, this dose was reduced down to 500 mg/m2 every 21 days because of toxicity. Doses of MTA were modified depending on nadir counts. Thirty-two eligible patients were enrolled and twenty-nine were evaluable for response. Three patients did not have repeat radiological testing to determine response because they went off study after only one cycle of treatment due to toxicity. In the 29 evaluable patients, there was 1 complete response, 4 partial responses and 14 patients with stable disease. Response rate was 17.2% (95% confidence intervals: 5.8%-35.8%). All responses occurred in the patients receiving a starting dose of MTA 500 mg/m2. Median time to progression for all eligible patients was 3.3 months. The most common toxicities experienced were mild to moderate fever, lethargy, anorexia, nausea, vomiting, stomatitis, abdominal pain, diarrhea, and skin rash. There was one death due to sepsis. Single-agent MTA at 500 mg/m2 given every three weeks has modest activity in metastatic colorectal carcinoma.

ChemInform Abstract: A Practical Synthesis of Multitargeted Antifolate LY231514.

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Glutamyl hydrolase and the multitargeted antifolate LY231514.

To examine the activity of glutamyl hydrolase (GH) on the poly-gamma-glutamates of multitargeted antifolate (MTA) (LY231514) and the effect of enhanced GH on the pharmacological activity of MTA. Expressed and purified GH were used to study the enzymatic cleavage of MTA poly-gamma-glutamates and wild-type and GH-enhanced H35 hepatoma cell lines to evaluate growth inhibition. MTA tri- and penta-gamma-glutamates were good substrates for human GH, having higher rates than MTX tri- and penta-gamma-glutamates. Preferential hydrolysis with human enzyme occurred at the two gamma-glutamyl bonds at the carboxyl end of the molecule, whereas the rat enzyme preferred the innermost gamma-linkage. Incubation of rat H35 hepatoma cell lines with MTA resulted in the intracellular accumulation of primarily tetra-, penta-, and hexa-gamma-glutamate. The formation of these were markedly reduced in H35D cells, which is a line resistant to antifolates chiefly through enhanced cellular levels of GH activity. MTA poly-gamma-glutamates are effective substrates for GH and their pharmacological effectiveness bears an inverse relationship to cellular GH activity. This observation, along with enhanced resistance to MTA of thymidylate synthase-amplified cells, substantiates the importance of the poly-gamma-glutamates of MTA inhibiting TS as the primary target. Further evidence for the inverse relationship of GH to classical antifolate pharmacological activity is established.

Randomized phase III trial of Taxol®/Carboplatin versus Taxol®Cisplatin in patients with advanced non-small cell lung cancer

platinum or non-platinum chemotherapy von Pawel J1, Manegold C2, Mattson K3, Postmus PE4, Smit EF4, Clarke S5, Saarinen A.1 Asklepios FachkIinik MŸnchen-Gauting, Germany; 2Thoraxklinik, Heidelberg, Germany; 3Division of Pulmonary Medicine, Helsinki University Central Hospital, Finland; 4Department of Pulmonary Diseases, Vrije Universiteit Amsterdam, 5Sydney Cancer Center, Sydney, Australia Purpose: Although new chemotherapeutic agents for NSCLC have been introduced, a critical need for active second-line agents still exists. This study evaluates the activity of MTA (multitargeted antifolate), in the treatment of NSCLC pts who relapsed following front-line therapy. MTA inhibits multiple folate-dependent enzymes and has activity in multiple tumors, i.e. NSCLC, breast, mesothelioma, head and neck, pancreas, and colon cancers. Methods: Pts with Stage IIIb or IV NSCLC who had relapsed during or within 3 months of prior therapy entered into 2 cohorts, depending on whether their prior therapy did (PT) or did not contain platinum (NP) (i.e. mitomycin, docetaxel, paclitaxel, vinorelbine, and/or gemcitabine). All pts received MTA 500 mg/m2 every 21 days with prophylactic dexamethasone. Results: 43 of 67 pts enrolled are evaluable for response. In the PT arm, 3 partial responses (PRs) were reported, for an overall response rate (RR) of 13%. In the NP arm, 1 complete and 5 PRs in 20 evaluable pts was reported, for a RR of 30%. Grade 3/4 toxicity (as % of cycles) includes Hgb: 6/1, WBC: 19/3, ANC: 14/9, platelets: 3/4, bilirubin: 2/0, elevated transaminases: 3/0, and infection: 1/2, respectively. One pt discontinued due to drug-related pneumonia. Four on-study deaths are not thought to be drug-related. Conclusion: MTA is active in the second-line treatment of NSCLC and appears noncross resistant with a variety of front-line agents.

A phase I study of the multitargeted antifolate (MTA) (LY 231514) in combination with oxaliplatin (LOHP) in metastatic solid tumors

A phase I study of the multitargeted antifolate (MTA) (LY 231514) in combination with oxaliplatin (LOHP) in metastatic solid tumors

In vitro sequence dependence for the multitargeted antifolate (MTA, LY231514) combined with other anticancer agents

In vitro sequence dependence for the multitargeted antifolate (MTA, LY231514) combined with other anticancer agents

Activity of the multitargeted antifolate LY231514 in the human tumor cloning assay.

This study was performed to evaluate the activity of the multitargeted antifolate (MTA or LY231514) against a broad range of human tumors taken directly from patients. Human tumor colony-forming units were treated with MTA at concentrations of 0.1, 1.0, and 10 microg/ml in 1-h exposure studies. The responses of a limited number of specimens were also evaluated concurrently in 1-h exposures to cisplatin, fluorouracil, irinotecan, and/or paclitaxel. Of 358 specimens plated in the 1-h exposure studies, 148 (41%) were evaluable. Overall, responses were observed in 3% of specimens (4/144) at 0.1 microg/ml, 11% (17/148) at 1.0 microg/ml, and 23% (33/141) at 10 microg/ml. In this range of concentrations achievable clinically, there was a significant concentration-response relationship. At 10 microg/ml in the 1-h exposure studies, the response rate in colorectal cancer specimens was 32% (9/28), and the response rate in non-small-cell lung cancer was 25% (6/24). Responses were also observed in several chemoresistant tumors, including renal cell carcinoma, hepatocellular carcinoma, mesothelioma, and pancreatic carcinoma. The activity of MTA was not completely cross-resistant with that of cisplatin, fluorouracil, irinotecan, and paclitaxel. MTA demonstrated in vitro activity against a spectrum of tumors, including several tumors generally considered chemoresistant.

A Practical Synthesis of Multitargeted Antifolate LY231514

A concise and scalable synthesis of LY231514 (1), a new pyrrolo[2,3-d]pyrimidine-based antitumor agent, is presented. Reaction of 2-bromo-4-arylbutanal 9 with 2,4-diamino-6-hydroxypyrimidine (10) regioselectively provided pyrrolo[2,3-d]pyrimidine 11, representing the core structure of the drug, in good yield. Assimilation of the glutamic acid residue by conventional means completed the synthesis. Development of the optimized synthetic route emphasized avoiding isolation of the relatively unstable aldehyde and bromoaldehyde intermediates.

Preclinical cellular pharmacology of LY231514 (MTA): a comparison with methotrexate, LY309887 and raltitrexed for their effects on intracellular folate and nucleoside triphosphate pools in CCRF-CEM cells.

LY231514 (N-[4-[2-(2-amino-3,4-dihydro-4-oxo-7H-pyrrolo[2,3-d]pyrimidin-5-yl)ethy l]-benzoyl]-L-glutamic acid) is a new folate-based antimetabolite currently in broad phase II clinical evaluation. Previous in vitro studies (C. Shih et al, CancerRes 57: 1116-1123, 1997) have suggested that LY231514 could be a multitargeted antifolate (MTA) capable of inhibiting thymidylate synthase (TS), dihydrofolate reductase (DHFR) and glycinamide ribonucleotide formyltransferase (GARFT). The present study compared LY231514 with methotrexate, raltitrexed and a glycinamide ribonucleotide formyltransferase inhibitor, LY309887, at 300, 100, 30 and 100 nM, respectively, for their effects on intracellular folate and at 100, 66, 20 and 30 nM respectively, for their effects on nucleoside triphosphate pools in CCRF-CEM cells. Methotrexate induced an accumulation of dihydrofolate species, together with a rapid depletion of ATP, GTP and all of the deoxynucleoside triphosphates. LY309887 caused an accumulation of 10-formyltetrahydrofolate, a rapid loss of ATP, GTP and dATP, but a slower loss in dCTP, dTTP and dGTP. Both LY231514 and raltitrexed had minimal effects on folate pools. In contrast, they caused rapid depletion of dTTP, dCTP and dGTP, but induced an accumulation of dATP at different rates, with raltitrexed doing so about 2.5 times faster. Most of the observed metabolic changes could be understood on the basis of current knowledge of folate and nucleotide metabolism. We concluded that LY231514 was distinct from methotrexate, LY309887 and raltitrexed based on their metabolic effects in CCRF-CEM cells, and that in this cell line the inhibitory effects of LY231514 were exerted primarily against the thymidylate cycle and secondarily against de novo purine biosynthesis.

New antimetabolites in cancer chemotherapy and their clinical impact.

It is almost 50 years since antimetabolites were first found to have clinical antitumour activity, with Farber's discovery that aminopterin could cause remission in acute leukaemia. In the following 10 years, methotrexate, 6-mercaptopurine and 5-fluorouracil (5-FU) found their way into clinical practice. Subsequently, cytosine arabinoside was found to have activity in acute leukaemia, but, until recently, other significant developments have involved optimizing the efficacy of existing antimetabolites, including the use of leucovorin with methotrexate or 5-FU. Recently, new antimetabolites have become a fertile area for anti-cancer drug research. Gemcitabine (GEMZAR) has emerged as an important new agent in several tumour types, including pancreatic, non-small-cell lung, bladder, breast and ovarian cancers. Capecitabine is an intriguing new prodrug, offering tumour selectivity and prolonged tumour exposure to 5-FU. More potent thymidylate synthase inhibitors have also emerged; raltitrexed is now commercially available for the treatment of colorectal cancer. Others under development include LY231514, which has other sites of action, hence the acronym MTA (multi-targeted antifolate). A novel target is glycinamide ribonucleotide formyltransferase (GARFT) and LY309887 and AG2034 are undergoing clinical investigation as GARFT inhibitors. A critical element with LY309887 appears to be co-administration of folate. It seems entirely possible that several novel antimetabolites will establish themselves in clinical practice in future for the treatment of solid tumours.

OP19. Quality of life assessments of patients with pancreatic cancer receiving MTA (LY231514, a multi-targeted antifolate)

OP19. Quality of life assessments of patients with pancreatic cancer receiving MTA (LY231514, a multi-targeted antifolate)

768 - Phase II study of a multi-targeted antifolate (LY231514) (MTA) as first line therapy in patients with locally advanced or metastatic colorectal cancer (MCC)

768 - Phase II study of a multi-targeted antifolate (LY231514) (MTA) as first line therapy in patients with locally advanced or metastatic colorectal cancer (MCC)

Synthesis of a Pyrido[2,3-d]pyrimidine Analogue of the Multitargeted Antifolate LY231514

Synthesis of a Pyrido[2,3-d]pyrimidine Analogue of the Multitargeted Antifolate LY231514