KHAPZORY Powder for solution for injection Ref.[10417] Active ingredients: Sodium levofolinate

5.1 Increased Gastrointestinal Toxicities with Fluorouracil

Leucovorin products increase the toxicities of fluorouracil [see Drug Interactions (7)]. Gastrointestinal toxicities, including stomatitis and diarrhea, occur more commonly and may be of greater severity and of prolonged duration. Deaths from severe enterocolitis, diarrhea, and dehydration have occurred in elderly patients receiving weekly d,l-leucovorin and fluorouracil.

Monitor patients for gastrointestinal toxicities. Do not initiate or continue therapy with KHAPZORY and fluorouracil in patients with symptoms of gastrointestinal toxicity until those symptoms have resolved. Monitor patients with diarrhea until it has resolved as rapid deterioration leading to death can occur.

5.2 Drug Interaction with Trimethoprim-Sulfamethoxazole

The concomitant use of d,l-leucovorin with trimethoprim-sulfamethoxazole for the acute treatment of Pneumocystis jiroveci pneumonia in patients with HIV infection was associated with increased rates of treatment failure and morbidity [see Drug Interation (7)].

The following clinical significant adverse reactions are described elsewhere in the labeling:

• Increased gastrointestinal toxicities with fluorouracil [see Warnings and Precautions (5.1)].

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.

High-Dose Methotrexate Therapy

Table 2 presents the frequency of adverse reactions which occurred during the administration of 58 courses of high-dose methotrexate 12 grams/m² followed by levoleucovorin rescue, for osteosarcoma, in 16 patients aged 6 to 21 years. Most patients received levoleucovorin 7.5 mg every 6 hours for 60 hours or longer, beginning 24 hours after completion of methotrexate administration.

Table 2. Adverse Reactions with High-Dose Methotrexate Therapy:

Combination with Fluorouracil in Colorectal Cancer

Table 3 presents the frequency of adverse reactions which occurred in 2 arms of a randomized controlled trial conducted by the North Central Cancer Treatment Group (NCCTG) in patients with metastatic colorectal cancer. The trial failed to show superior overall survival with fluorouracil + levoleucovorin compared to fluorouracil + d,l-leucovorin. Patients were randomized to fluorouracil 370 mg/m² intravenously and levoleucovorin 100 mg/m² intravenously, both daily for 5 days, or to fluorouracil 370 mg/m² intravenously and d,l-leucovorin 200 mg/m² intravenously, both daily for 5 days. Treatment was repeated week 4 and week 8, and then every 5 weeks until disease progression or unacceptable toxicity.

Table 3. Adverse Reactions Occurring in ≥10% of Patients in Either Arm:

^* Includes abdominal pain, upper abdominal pain, lower abdominal pain, and abdominal tenderness

The following adverse reactions have been identified during post-approval use of levoleucovorin products. Because these adverse 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. The following have been reported:

• Dermatologic: pruritus, rash
• Respiratory: dyspnea
• Other Clinical Events: temperature change, rigors, allergic reactions

7.1 Effects of Leucovorin Products on Other Drugs

Antiepileptic Drugs

Folic acid in large amounts may counteract the antiepileptic effect of phenobarbital, phenytoin and primidone and increase the frequency of seizures in susceptible children. It is not known whether folinic acid has the same effects; however, both folic and folinic acids share some common metabolic pathways. Monitor patients taking folinic acid in combination with antiepileptic drugs.

Fluorouracil

Leucovorin products increase the toxicity of fluorouracil. Do not initiate or continue therapy with Fusilev and fluorouracil in patients with symptoms of gastrointestinal toxicity until those symptoms have resolved. Monitor patients with diarrhea until the diarrhea has resolved, as rapid deterioration leading to death can occur [see Warnings and Precautions (5.2)].

Trimethoprim-Sulfamethoxazole

The concomitant use of d,l-leucovorin with trimethoprim-sulfamethoxazole for the acute treatment of Pneumocystis jiroveci pneumonia in patients with HIV infection was associated with increased rates of treatment failure and morbidity in a placebo-controlled study [see Warnings and Precautions (5)].

Risk Summary

There are limited data with levoleucovorin use in pregnant women. Animal reproduction studies have not been conducted with levoleucovorin.

Levoleucovorin is administered in combination with methotrexate or fluorouracil, which can cause embryo-fetal harm. Refer to methotrexate or fluorouracil prescribing information for additional information.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Risk Summary

There are no data on the presence of levoleucovorin in human milk or its effects on the breastfed infant or on milk production.

Levoleucovorin is administered in combination with methotrexate or fluorouracil. Refer to methotrexate or fluorouracil prescribing information for additional information.

The safety and effectiveness of KHAPZORY have been established in pediatric patients for rescue after high-dose methotrexate therapy in osteosarcoma and diminishing the toxicity associated with overdosage of folic acid antagonists or impaired methotrexate elimination. Use of levoleucovorin in pediatric patients is supported by open-label clinical trial data in 16 pediatric patients 6 years of age and older, with additional supporting evidence from literature [see Clinical Studies (14.1)].

The safety and effectiveness of KHAPZORY have not been established for the treatment of pediatric patients with advanced metastatic colorectal cancer.

Clinical studies of levoleucovorin in the treatment of osteosarcoma did not include patients aged 65 years and over to determine whether they respond differently from younger patients.

In the NCCTG clinical trial of levoleucovorin in combination with fluorouracil in the treatment of metastatic colorectal cancer, adverse reactions were consistent with fluorouracil related toxicity and were similar for patients age 65 years and older and patients younger than 65 [see Clinical Studies (14.2)].