Aminolevulinic acid

12.1 Mechanism of Action ALA occurs endogenously as a metabolite that is formed in the mitochondria from succinyl-CoA and glycine. Exogenous administration of ALA leads to accumulation of the ALA metabolite PpIX in tumor cells. The reason for the accumulation of PpIX in neoplastic brain tissue is not known. During glioma surgery, Gleolan is used with an operating microscope adapted with a blue emitting light source (power density 40-80 mW/cm 2 ) and filters for excitation light of wavelength 375 to 440 nm, and observation at wavelengths of 620 to 710 nm. This allows tumor tissue to be visualized as red fluorescence. Tissue lacking sufficient PpIX concentrations appears blue.

1 INDICATIONS AND USAGE Gleolan is indicated in patients with glioma [suspected World Health Organization (WHO) Grades III or IV on preoperative imaging] as an adjunct for the visualization of malignant tissue during surgery. Gleolan is an optical imaging agent indicated in patients with glioma (suspected World Health Organization Grades III or IV on preoperative imaging) as an adjunct for the visualization of malignant tissue during surgery. ( 1 )

2 DOSAGE AND ADMINISTRATION For oral use only ( 2.1 ) Recommended reconstituted oral dose of Gleolan is 20 mg/kg. ( 2.1 ) Administer Gleolan to patient orally 3 hours (range 2 to 4 hours) before anesthesia. ( 2.1 ) See Full Prescribing Information for reconstitution information. ( 2.2 ) Use appropriate visualization techniques with appropriate surgical microscopes and light source filters. ( 2.4 ) 2.1 Recommended Dose For oral use only The recommended oral dose of reconstituted Gleolan is 20 mg / kg body weight. More than 1 vial may be required. 2.2 Reconstitution of Gleolan Gleolan powder must be reconstituted prior to administration by a healthcare provider according to the following instructions: Determine the total number of vials needed to achieve the intended dose for the patient according to the equation below (rounded up to the nearest whole vial): # of vials = Patient Body Weight (kg) 75 kg / vial Completely remove the white cap and aluminum crimp seal from each vial. Remove and retain the rubber stopper from the vial. Using an appropriate volumetric measuring device (e.g., flask, graduated cylinder, dosing syringe), measure 50 mL of drinking water and add to each vial containing 1,500 mg of Gleolan. Gently swirl the vial to completely dissolve the powder. The resulting reconstituted solution (30 mg of Gleolan per mL) is clear and colorless to slightly yellowish. If required, replace the stopper and store reconstituted solution for up to 24 hours at room temperature prior to administration. 2.3 Gleolan Administration Gleolan is for ORAL USE ONLY. The reconstituted Gleolan solution is administered according to the following steps: Calculate the administration volume, in mL, to achieve the intended dose according to the following equation: Administration Volume (mL) = Patient Body Weight (kg) * 20 mg/kg 30 mg/mL Transfer the entire contents of the prepared vial(s) into an appropriate dosing container (e.g., oral medicine bottle); ensure the entire contents of the vials are transferred. After transfer, discard the empty vial(s). Using a disposable volumetric syringe, remove the administration volume of reconstituted Gleolan solution from the dosing container and transfer to a separate oral dosing container. Discard unneeded volume of Gleolan solution. Administer orally 3 hours (range 2 to 4 hours) prior to induction of anesthesia. 2.4 Imaging Instructions Gleolan should be used with a standard surgical operating microscope adapted with a blue light emitting light source (power density 40-80 mW/cm 2 ) and ancillary excitation and emission filters to visualize fluorescence excitation in the wavelength of 375 to 440 nm and for observation from 620 to 710 nm. Filters transmit porphyrin fluorescence as red-violet, as well as a fraction of backscattered blue excitation light necessary for distinguishing nonfluorescing tissue. Gleolan should only be used by neurosurgeons who have completed a training program on use of fluorescence in surgery. Training is provided by the distributor.

6 ADVERSE REACTIONS Adverse reactions occurring in >1% of patients in the week following surgery were pyrexia, hypotension, nausea, and vomiting. ( 6.1 ) Adverse reactions occurring in < 1% of patients in the first 6 weeks after surgery were: chills, photosensitivity reaction, solar dermatitis, hypotension, abnormal liver function test, and diarrhea. ( 6.1 ) Neurologic events related to the surgical procedure occurred in 29% of patients and included: aphasia, hemiparesis, hemianopia, headache, seizure, hemiplegia, monoparesis, hypoesthesia, and brain edema. ( 6.1 ) Elevated liver enzymes occurred in clinical studies. There were no cases of liver failure. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact NXDC toll-free at (844) 517-5252 and adverseevents@nxdevcorp.com or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety of Gleolan is supported by data from 5 open label clinical studies, which included 527 patients with glioma who received ALA HCl. Adverse reactions that occurred in > 1% of patients in the week following surgery were pyrexia, hypotension, nausea, and vomiting. Adverse reactions occurring in the first 6 weeks after surgery in < 1% of patients were: chills, photosensitivity reaction, solar dermatitis, hypotension, abnormal liver function test, and diarrhea. One patient experienced respiratory failure due to drug overdose [see Overdosage (10) ] . Neurologic Events Nervous system disorders occurred in 29% of patients within the first week after surgery. Events occurring in > 1% of patients included aphasia (8%), hemiparesis (7.8%), hemianopsia (3.2%), headache (2.7%), seizure (1.9%), hemiplegia (1.9%), monoparesis (1.3%) and hypoesthesia (1.1%). Brain edema occurred in < 1 % of patients in the first 6 weeks after surgery. In a randomized clinical trial (Study 3), the numbers of serious neurologic adverse events in the post operative period were higher in patients randomized to ALA fluorescence arm compared to the control arm. An imbalance was notable for the adverse events aphasia, ataxia, convulsion and hemianopsia, and is likely related to the higher amount of brain resection performed in the ALA arm. At longer follow up periods, the numbers between the two arms appeared similar [see Clinical Trials (14) ] . Elevated Liver Enzymes Worsening of ≥ 2 Common Toxicity Criteria (CTC) grades in alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) occurred in (15.8% and 11.6%, respectively) within the first week after surgery. Absolute levels ranged from 2 times to greater than 10 times the upper limit of normal (ULN) for each parameter. At 6 weeks, ALT remained elevated in 2.9% of patients (range 2 to greater than 5 × ULN), and GGT was elevated in 7.5% of patients (range 2 to greater than 10 × ULN). No cases of liver failure occurred. 6.2 Post Marketing Experience The following adverse reactions are among those that have been identified during post-approval use of Gleolan outside of the United States. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Immune Disorders : anaphylactic shock, angioedema, drug eruption, urticaria, erythema. Metabolism and Nutrition Disorders : metabolic acidosis.

7 DRUG INTERACTIONS Phototoxic Drugs Patients exposed to a photosensitizing agent may experience a phototoxic skin reaction (severe sunburn). Due to the risk of possible phototoxic reactions, avoid administering phototoxic drugs such as St. John's wort, griseofulvin, thiazide diuretics, sulfonylureas, phenothiazines, sulphonamides, quinolones and tetracyclines, and topical preparations containing ALA for 24 hours before and after administration of Gleolan.