oxaliplatin injection 12 CLINICAL PHARMACOLOGY

Prescribing Information

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Oxaliplatin undergoes nonenzymatic conversion in physiologic solutions to active derivatives via displacement of the labile oxalate ligand. Several transient reactive species are formed, including monoaquo and diaquo DACH platinum, which covalently bind with macromolecules. Both inter- and intrastrand Pt-DNA crosslinks are formed. Crosslinks are formed between the N7 positions of two adjacent guanines (GG), adjacent adenine-guanines (AG), and guanines separated by an intervening nucleotide (GNG). These crosslinks inhibit DNA replication and transcription. Cytotoxicity is cell-cycle nonspecific.

In vivo studies have shown antitumor activity of oxaliplatin against colon carcinoma. In combination with fluorouracil, oxaliplatin exhibits in vitro and in vivo antiproliferative activity greater than either compound alone in several tumor models (HT29 [colon], GR [mammary], and L1210 [leukemia]).

12.2 Pharmacodynamics

A pharmacodynamic relationship between platinum ultrafiltrate levels and clinical safety and effectiveness has not been established.

12.3 Pharmacokinetics

The reactive oxaliplatin derivatives are present as a fraction of the unbound platinum in plasma ultrafiltrate. After a single 2-hour intravenous infusion of Oxaliplatin at a dose of 85 mg/m2, pharmacokinetic parameters expressed as ultrafiltrable platinum were Cmax of 0.814 mcg/mL and volume of distribution of 440 L.

Interpatient and intrapatient variability in ultrafiltrable platinum exposure (AUC0–48hr) assessed over 3 cycles was 23% and 6%, respectively.

Distribution

At the end of a 2-hour infusion of Oxaliplatin, approximately 15% of the administered platinum is present in the systemic circulation. The remaining 85% is rapidly distributed into tissues or eliminated in the urine. The decline of ultrafiltrable platinum levels following Oxaliplatin administration is triphasic, including two distribution phases (t½α; 0.43 hours and t½β; 16.8 hours).

In patients, plasma protein binding of platinum is irreversible and is greater than 90%. The main binding proteins are albumin and gamma-globulins.

Platinum also binds irreversibly and accumulates (approximately 2-fold) in erythrocytes, where it appears to have no relevant activity. No platinum accumulation was observed in plasma ultrafiltrate following 85 mg/m2 every two weeks.

Elimination

The decline of ultrafiltrable platinum concentrations from plasma is characterized by a long terminal elimination phase (t½γ; 391 hour).

Metabolism

Oxaliplatin undergoes rapid and extensive nonenzymatic biotransformation. There is no evidence of cytochrome P450-mediated metabolism in vitro.

Up to 17 platinum-containing derivatives have been observed in plasma ultrafiltrate samples from patients, including several cytotoxic species (monochloro DACH platinum, dichloro DACH platinum, and monoaquo and diaquo DACH platinum) and a number of noncytotoxic, conjugated species.

Excretion

The major route of platinum elimination is renal excretion. At five days after a single 2-hour infusion of Oxaliplatin, urinary elimination accounted for about 54% of the platinum eliminated, with fecal excretion accounting for only about 2%. Platinum was cleared from plasma at a rate (10–17 L/h) that was similar to or exceeded the average human glomerular filtration rate (GFR; 7.5 L/h). The renal clearance of ultrafiltrable platinum is significantly correlated with GFR.

Special Populations

Sex

There was no significant effect of sex on the clearance of ultrafiltrable platinum.

Patients with renal impairment

Patients with normal function (CLcr greater than 80 mL/min) and patients with mild (CLcr=50–80 mL/min) and moderate (CLcr equal to 30–49 mL/min) renal impairment received Oxaliplatin 85 mg/m2 and those with severe (CLcr less than 30 mL/min) renal impairment received Oxaliplatin 65 mg/m2. Mean dose adjusted AUC of unbound platinum was 40%, 95%, and 342% higher for patients with mild, moderate, and severe renal impairment, respectively, compared to patients with normal renal function. Mean dose adjusted Cmax of unbound platinum appeared to be similar among the normal, mild and moderate renal function groups, but was 38% higher in the severe group than in the normal group [see Dosage and Administration (2.3)].

Drug Interaction Studies

No pharmacokinetic interaction between Oxaliplatin 85 mg/m2 and infusional fluorouracil has been observed in patients treated every 2 weeks, but increases of fluorouracil plasma concentrations by approximately 20% have been observed with doses of 130 mg/m2 of Oxaliplatin administered every 3 weeks.

In vitro platinum was not displaced from plasma proteins by the following medications: erythromycin, salicylate, sodium valproate, granisetron, and paclitaxel.

In vitro oxaliplatin does not inhibit human cytochrome P450 isoenzymes.

Medication Guide

MEDICATION GUIDE

Patient Information Oxaliplatin (ox-Al-ah-platin) injection for intravenous use
What is the most important information I should know about Oxaliplatin? Oxaliplatin can cause serious allergic reactions, including allergic reactions that can lead to death. Oxaliplatin is a platinum-based medicine. Serious allergic reactions including death can happen in people who take Oxaliplatin and who have had previous allergic reactions to platinum-based medicines. Serious allergic reactions can happen within a few minutes of your Oxaliplatin infusion or any time during your treatment with Oxaliplatin. Get emergency help right away if you: • have trouble breathing • feel like your throat is closing up • chest tightness Call your doctor right away if you have any of the following signs or symptoms of an allergic reaction:
• rash • flushed face • hives • itching • swelling of your lips or tongue, face or eyelids		• wheezing • sudden cough • dizziness or feel faint • sweating • chest pain
See "What are the possible side effects of Oxaliplatin?" for information about other serious side effects.
What is Oxaliplatin? Oxaliplatin is an anti-cancer (chemotherapy) medicine that is used with other anti-cancer medicines called fluorouracil and leucovorin to treat people with: • stage III colon cancer after surgery to remove the tumor • advanced colon or rectal cancer (colorectal cancer) It is not known if Oxaliplatin is safe and effective in children.
Do not receive Oxaliplatin if you are allergic to Oxaliplatin or any of the ingredients in Oxaliplatin or if you are allergic to other platinum-based medicines. See the end of this leaflet for a complete list of the ingredients in Oxaliplatin Injection, USP. Ask your doctor if you are not sure if you have taken a platinum-based medicine.
Before receiving Oxaliplatin, tell your doctor about all of your medical conditions, including if you: • have an infection • have lung, liver, or kidney problems • have bleeding problems • have or had heart problems such as an abnormal heart test called an electrocardiogram (ECG or EKG), a condition called long QT syndrome, an irregular or slow heartbeat, or a family history of heart problems • have had changes in the level of certain blood salt (electrolytes) levels, including potassium, magnesium, and calcium • are pregnant or plan to become pregnant. Oxaliplatin can harm your unborn baby. Tell your doctor right away if you become pregnant or think you may be pregnant during treatment with Oxaliplatin. Females who are able to become pregnant: o Your doctor will do a pregnancy test before you start treatment with Oxaliplatin. o You should use effective birth control (contraception) during treatment with Oxaliplatin and for 9 months after the final dose. Talk to your doctor about forms of birth control that may be right for you. Males with female partners who are able to become pregnant should use effective birth control during treatment with Oxaliplatin and for 6 months after the final dose. • are breastfeeding or plan to breastfeed. It is not known if Oxaliplatin passes into your breast milk. Do not breastfeed during treatment with Oxaliplatin and for 3 months after the final dose. Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Know the medicines you take. Keep a list of them and show it to your doctor and pharmacist when you get a new medicine.
How will I receive Oxaliplatin? • Oxaliplatin is given to you into your vein through an intravenous (IV) tube. • Your doctor will prescribe Oxaliplatin in a dose that is right for you. • Your doctor may change how often you receive Oxaliplatin, your dose, or how long your infusion will take. • You and your doctor will decide how many Oxaliplatin treatments you will receive. • It is very important that you do exactly what your doctor and nurse tell you to do. • Some medicines may be given to you before Oxaliplatin to help prevent nausea and vomiting. • Each treatment course is given to you over 2 days. You will receive Oxaliplatin on the first day only. • There are usually 14 days (2 weeks) between each chemotherapy treatment course. • It is important for you to keep all of your medical appointments. Call your doctor if you miss an appointment. There may be special instructions for you. Treatment Day 1: • Oxaliplatin and leucovorin will be given through a thin plastic tube into a vein (intravenous infusion or IV) and given for 2 hours. You will be watched by a healthcare provider during this time. • Right after the Oxaliplatin and leucovorin are given, 2 doses of fluorouracil will be given. The first dose is given right away into your IV tube. The second dose will be given into your IV tube over the next 22 hours, using a pump device. Treatment Day 2: You will not get Oxaliplatin on Day 2. Leucovorin and fluorouracil will be given the same way as on Day 1. The fluorouracil will be given through your IV with a pump. If you have any problems with the pump or the tube, call your doctor, your nurse, or the person who is responsible for your pump. Do not let anyone other than a healthcare provider touch your infusion pump or tubing.
What should I avoid while receiving Oxaliplatin? • Avoid cold temperatures and cold objects. Cover your skin if you go outdoors in cold temperatures. • Do not drink cold drinks or use ice cubes in drinks. • Do not put ice or ice packs on your body. • Oxaliplatin can cause dizziness, vision problems, or vision loss that can affect your ability to drive or use machines. You should not drive or operate machinery if you develop these symptoms while receiving Oxaliplatin. See "How can I reduce the side effects caused by cold temperatures?" for more information. Talk with your doctor and nurse about your level of activity during treatment with Oxaliplatin. Follow their instructions.
What are the possible side effects of Oxaliplatin? Oxaliplatin can cause serious side effects, including: • See "What is the most important information I should know about Oxaliplatin?" • Nerve problems. Oxaliplatin can affect how your nerves work and make you feel. Nerve problems may happen with the first treatment or within two days after your treatment with Oxaliplatin. Nerve problems may last a short time (acute) or may become persistent. Symptoms may improve after stopping treatment with Oxaliplatin. Exposure to cold or cold objects may cause or worsen nerve problems. Tell your doctor right away if you get any signs of nerve problems, including: o very sensitive to cold temperatures and cold objects o trouble breathing, swallowing, or saying words, jaw tightness, odd feelings in your tongue, or chest pressure o pain, tingling, burning (pins and needles, numb feeling) in your hands, feet, or around your mouth or throat, which may cause problems walking, fall and fall-related injuries, or problems performing activities of daily living For information on ways to lessen or help with nerve problems, see the section "How can I reduce the side effects caused by cold temperatures?" below. • Severe low blood cell counts (myelosuppression). Oxaliplatin when used with fluorouracil and leucovorin can cause low blood cell counts. Low blood cell counts are common with Oxaliplatin when used with fluorouracil and leucovorin and can lead to serious infection and death. Your doctor will do blood tests to check your blood cell counts before starting Oxaliplatin and during treatment. Tell your doctor right away if you have a fever greater than 100.9°F (38.3°C) or a prolonged fever greater than 100.4°F (38°C) for more than one hour (febrile neutropenia). Call your doctor right away if you get any of the following signs of infection:
	o chills or shivering o pain on swallowing o sore throat o cough that brings up mucus		o burning or pain on urination o redness or swelling at intravenous site o persistent diarrhea
• Posterior Reversible Encephalopathy Syndrome (PRES). PRES is a rare condition that affects the brain. Tell your doctor right away if you have any of the following signs and symptoms of PRES: o headache o confusion or a change in the way you think o seizures o vision problems, such as blurriness or vision loss
• Lung Problems. Oxaliplatin can cause lung problems that may lead to death. Tell your doctor right away if you get any of the following symptoms as these may be indicators of a serious lung disease:
	o shortness of breath o wheezing o cough
• Liver problems (hepatotoxicity). Your doctor will do blood tests to check your liver when you start receiving Oxaliplatin, and before each treatment course as needed. • Heart problems. Oxaliplatin can cause heart problems that have led to death. Your doctor may do blood and heart tests during treatment with Oxaliplatin if you have certain heart problems. If you faint (lose consciousness), or have an irregular heartbeat or chest pain during treatment with Oxaliplatin, get medical help right away as this may be a sign of a serious heart condition. • Muscle problems. Oxaliplatin can cause muscle damage (rhabdomyolysis) which can lead to death. Tell your doctor right away if you have muscle pain and swelling, along with weakness, fever, red-brown urine, decreased amount of urine or trouble urinating. • Bleeding problems (hemorrhage). Oxaliplatin when used with fluorouracil and leucovorin can cause bleeding problems (hemorrhage) that can lead to death. Your risk of bleeding may increase if you are also taking a blood thinner medicine. Tell your healthcare provider if you have any signs or symptoms of bleeding, including:
	o blood in your stools or black stools (looks like tar) o pink or brown urine o unexpected bleeding, or bleeding that is severe or you cannot control o vomit blood or vomit that looks like coffee grounds o cough up blood or blood clots o increased bruising o dizziness o weakness o confusion o changes in speech o headache that lasts a long time
The most common side effects of Oxaliplatin include:
• numbness, pain, tingling, and/or burning along the nerves • low white blood cells (blood cells important for fighting infection) • low platelet count (important for clotting and to control bleeding) • low red blood cells (blood cells that carry oxygen to the tissues) • nausea		• changes in liver function tests • diarrhea • vomiting • tiredness • mouth sores
Oxaliplatin may cause fertility problems in males and females. Talk to your doctor if this is a concern for you. Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of Oxaliplatin. For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
How can I reduce the side effects caused by cold temperatures? • Cover yourself with a blanket while you are getting your Oxaliplatin infusion. • Do not breathe deeply when exposed to cold air. • Wear warm clothing in cold weather at all times. Cover your mouth and nose with a scarf or a pull-down cap (ski cap) to warm the air that goes to your lungs. • Wear gloves when taking things from the freezer or refrigerator. • Drink fluids warm or at room temperature. • Always drink through a straw. • Do not use ice chips if you have nausea or mouth sores. Ask your doctor about what you can use. • Be aware that most metals are cold to touch, especially in the winter. These include your car door and mailbox. Wear gloves to touch cold objects. • Do not run the air conditioning at high levels in the house or in the car in hot weather. • If your body gets cold, warm-up the affected part. If your hands get cold, wash them with warm water. • Always let your doctor know before your next treatment how well you did since your last visit. Your doctor may have other useful tips for helping you with side effects.
General information about the safe and effective use of Oxaliplatin Medicines are sometimes prescribed for purposes other than those listed in the Patient Information leaflet. You can ask your doctor or pharmacist for information about Oxaliplatin Injection, USP that is written for health professionals.
What are the ingredients in Oxaliplatin? Active ingredient: oxaliplatin Concentrate for solution for infusion inactive ingredients: water for injection, tartaric acid, sodium hydroxide Paraplatin® and Platinol® are registered trademarks of Bristol-Myers Squibb Company. Oxaliplatin Injection, USP (concentrate solution for infusion)

This Patient Information has been approved by the U.S. Food and Drug Administration.

Distributed by Hospira, Inc., Lake Forest, IL 60045

LAB-1359-4.0

Revised: 9/2024

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