Zelboraf Drug Information

Unresectable or Metastatic Melanoma ZELBORAF ® is indicated for the treatment of patients with unresectable or metastatic melanoma with BRAF V600E mutation as detected by an FDA-approved test. Limitation of Use: ZELBORAF is not indicated for treatment of patients with wild-type BRAF melanoma.

Erdheim-Chester Disease ZELBORAF ® is indicated for the treatment of patients with Erdheim-Chester Disease (ECD) with BRAF V600 mutation.

Patient Selection for Treatment of Melanoma Confirm the presence of BRAF V600E mutation in melanoma tumor specimens prior to initiation of treatment with ZELBORAF. Information on FDA-approved tests for the detection of BRAF V600 mutations in melanoma is available at http://www.fda.gov/CompanionDiagnostics.

Recommended Dose

The recommended dose of ZELBORAF is 960 mg (four 240 mg tablets) orally every 12 hours with or without a meal. A missed dose can be taken up to 4 hours prior to the next dose. Treat patients with ZELBORAF until disease progression or unacceptable toxicity occurs.

Do not take an additional dose if vomiting occurs after ZELBORAF administration, but continue with the next scheduled dose. Do not crush or chew the tablets.

Dose Modifications For New Primary Cutaneous Malignancies

No dose modifications are recommended. For Other Adverse Reactions: Permanently discontinue ZELBORAF for any of the following: Grade 4 adverse reaction, first appearance (if clinically appropriate) or second appearance QTc prolongation > 500 ms and increased by > 60 ms from pre-treatment values Withhold ZELBORAF for NCI-CTCAE (v4.0) intolerable Grade 2 or greater adverse reactions. Upon recovery to Grade 0–1, restart ZELBORAF at a reduced dose as follows: 720 mg twice daily for first appearance of intolerable Grade 2 or Grade 3 adverse reactions 480 mg twice daily for second appearance of Grade 2 (if intolerable) or Grade 3 adverse reactions or for first appearance of Grade 4 adverse reaction (if clinically appropriate) Do not dose reduce to below 480 mg twice daily.

Dose Modification for Strong CYP3A4 Inducers

Avoid concomitant use of strong CYP3A4 inducers during treatment with ZELBORAF. If concomitant use of a strong CYP3A4 inducer is unavoidable, increase the dose of ZELBORAF by 240 mg (one tablet) as tolerated. After discontinuation of a strong CYP3A4 inducer for two weeks, resume the ZELBORAF dose that was taken prior to initiating the strong CYP3A4 inducer.

Clinical Trials Experience

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not predict the rates observed in a broader patient population in clinical practice. Unresectable or Metastatic Melanoma with BRAF V600E Mutation This section describes adverse drug reactions (ADRs) identified from analyses of Trial 1 and Trial 2. In Trial 2, 132 patients with metastatic melanoma and failure of at least one prior systemic therapy received treatment with ZELBORAF 960 mg orally twice daily.

Table 1 presents adverse reactions reported in at least 10% of unresectable or metastatic melanoma patients treated with ZELBORAF. The most common adverse reactions of any grade (≥ 30% in either study) in ZELBORAF-treated patients were arthralgia, rash, alopecia, fatigue, photosensitivity reaction, nausea, pruritus, and skin papilloma. The most common (≥ 5%) Grade 3 adverse reactions were cuSCC and rash.

The incidence of Grade 4 adverse reactions was ≤ 4% in both studies. The incidence of adverse events resulting in permanent discontinuation of study medication in Trial 1 was 7% for the ZELBORAF arm and 4% for the dacarbazine arm. In Trial 2, the incidence of adverse events resulting in permanent discontinuation of study medication was 3% in ZELBORAF-treated patients.

Table 1 Adverse Reactions Reported in ≥ 10% of Unresectable or Metastatic Melanoma Patients Treated with ZELBORAF Adverse drug reactions, reported using MedDRA and graded using NCI-CTC-AE v 4.0 (NCI common toxicity criteria) for assessment of toxicity. 0 Clinically relevant adverse reactions reported in < 10% of unresectable or metastatic melanoma patients treated with ZELBORAF in the Phase 2 and Phase 3 studies include: Skin and subcutaneous tissue disorders: palmar-plantar erythrodysesthesia syndrome, keratosis pilaris, panniculitis, erythema nodosum, Stevens-Johnson syndrome, toxic epidermal necrolysis Musculoskeletal and connective tissue disorders: arthritis, Dupuytren's contracture Nervous system disorders: neuropathy peripheral, VII th nerve paralysis Neoplasms benign, malignant and unspecified (includes cysts and polyps): basal cell carcinoma, oropharyngeal squamous cell carcinoma Infections and infestations: folliculitis Eye disorders: retinal vein occlusion Vascular disorders: vasculitis Cardiac disorders: atrial fibrillation Table 2 shows the incidence of worsening liver laboratory abnormalities in Trial 1 summarized as the proportion of patients who experienced a shift from baseline to Grade 3 or 4. In Trial 4, 22 patients with BRAF V600 mutation-positive ECD received ZELBORAF 960 mg twice daily. The median treatment duration for ECD patients in this study was 14.2 months.

Table 3 presents adverse reactions reported in at least 20% of BRAF V600 mutation-positive ECD patients treated with ZELBORAF. In Trial 4, the most commonly reported adverse reactions (> 50%) in patients with BRAF V600 mutation- positive ECD treated with ZELBORAF were arthralgia, rash maculo-papular, alopecia, fatigue, electrocardiogram QT interval prolonged, and skin papilloma. The most common (≥ 10%) Grade ≥ 3 adverse reactions were squamous cell carcinoma of the skin, hypertension, rash maculo-papular, and arthralgia.

The incidence of adverse reactions resulting in permanent discontinuation of study medication was 32%. 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. Neoplasms benign, malignant and unspecified (incl. cysts and polyps): Progression of pre-existing chronic myelomonocytic leukemia with NRAS mutation.

Skin and subcutaneous tissue disorders: Drug reaction with eosinophilia and systemic symptoms (DRESS syndrome). Blood and lymphatic systems disorder: Neutropenia Injury, poisoning and procedural complications: Radiation sensitization and recall. Gastrointestinal disorders: Pancreatitis Renal and urinary disorders: Acute interstitial nephritis, acute tubular necrosis.

Musculoskeletal and connective tissue disorders: Dupuytren's contracture and plantar fascial fibromatosis. Immune system disorders: Sarcoidosis

Effect of Strong CYP3A4 Inhibitors or Inducers on Vemurafenib Strong CYP3A4 Inhibitors Coadministration of a strong CYP3A4 inhibitor increased vemurafenib plasma concentrations and may lead to increased toxicity. Avoid coadministration of ZELBORAF with strong CYP3A4 inhibitors. If coadministration of a strong CYP3A4 inhibitor is unavoidable, consider dose reduction of ZELBORAF, if clinically indicated.

Strong CYP3A4 Inducers Coadministration of ZELBORAF with rifampin, a strong CYP3A4 inducer, decreased vemurafenib plasma concentrations and may result in decreased efficacy. Avoid coadministration of ZELBORAF with strong CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin), and replace these drugs with alternative drugs when possible. If coadministration of a strong CYP3A4 inducer is unavoidable, increase the dose of ZELBORAF by 240 mg (one tablet) as tolerated.

Effect of Vemurafenib on CYP1A2 Substrates Coadministration of ZELBORAF with tizanidine, a sensitive CYP1A2 substrate, increased tizanidine systemic exposure by 4.7-fold. Avoid concomitant use of ZELBORAF with drugs having a narrow therapeutic window that are predominantly metabolized by CYP1A2. If coadministration cannot be avoided, monitor closely for toxicities and consider a dose reduction of concomitant CYP1A2 substrates.

Concurrent Ipilimumab Increases in transaminases and bilirubin occurred in a majority of patients who received concurrent ipilimumab and ZELBORAF.

Effect of Vemurafenib on P-gp Substrates Coadministration of ZELBORAF with digoxin, a sensitive P-glycoprotein (P-gp) substrate, increased digoxin systemic exposure by 1.8-fold. Avoid concurrent use of P-gp substrates known to have narrow therapeutic indices. If use of these medications is unavoidable, consider dose reduction of P-gp substrates with narrow therapeutic indices.

Pregnancy Risk Summary Based on its mechanism of action, ZELBORAF can cause fetal harm when administered to a pregnant woman. There are no available data on the use of ZELBORAF in pregnant women to determine the drug-associated risk; however, placental transfer of vemurafenib to a fetus has been reported. Exposure to vemurafenib could not be achieved in animals at levels sufficient to fully address its potential toxicity in pregnant women.

Advise pregnant women of the potential harm to a fetus. The estimated background risks of major birth defects and miscarriage for the indicated population(s) are unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Data Animal Data Vemurafenib showed no evidence of developmental toxicity in rat fetuses at doses up to 250 mg/kg/day (approximately 1.3 times the clinical exposure at 960 mg twice daily based on AUC) or rabbit fetuses at doses up to 450 mg/kg/day (approximately 0.6 times the clinical exposure at 960 mg twice daily based on AUC). Fetal drug levels were 3–5% of maternal levels, indicating that vemurafenib has the potential to be transmitted from the mother to the developing fetus.

Pediatric Use The safety and effectiveness of ZELBORAF in pediatric patients have not been established. Vemurafenib was studied in 6 adolescent patients 15 to 17 years of age with unresectable or metastatic melanoma with BRAF V600 mutation. A maximum tolerated dose was not reached with doses up to vemurafenib 960 mg twice daily.

No new safety signals were observed. Vemurafenib steady-state exposure in these 6 adolescent patients was generally similar to that in adults.

There is no information on overdosage of ZELBORAF.