Cobimetinib

12.1 Mechanism of Action Cobimetinib is a reversible inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase 1 (MEK1) and MEK2. MEK proteins are upstream regulators of the extracellular signal-related kinase (ERK) pathway, which promotes cellular proliferation. BRAF V600E and K mutations result in constitutive activation of the BRAF pathway which includes MEK1 and MEK2. In mice implanted with tumor cell lines expressing BRAF V600E, cobimetinib inhibited tumor cell growth. Cobimetinib and vemurafenib target two different kinases in the RAS/RAF/MEK/ERK pathway. Compared to either drug alone, coadministration of cobimetinib and vemurafenib resulted in increased apoptosis in vitro and reduced tumor growth in mouse implantation models of tumor cell lines harboring BRAF V600E mutations. Cobimetinib also prevented vemurafenib-mediated growth enhancement of a wild-type BRAF tumor cell line in an in vivo mouse implantation model.

1 INDICATIONS AND USAGE COTELLIC ® is a kinase inhibitor indicated: For the treatment of adult patients with unresectable or metastatic melanoma with a BRAF V600E or V600K mutation, in combination with vemurafenib. ( 1.1 , 14.1 ) As a single agent for the treatment of adult patients with histiocytic neoplasms. ( 1.2 , 14.2 ) 1.1 Unresectable or Metastatic Melanoma COTELLIC ® is indicated for the treatment of adult patients with unresectable or metastatic melanoma with a BRAF V600E or V600K mutation, in combination with vemurafenib. 1.2 Histiocytic Neoplasms COTELLIC®, as a single agent, is indicated for the treatment of adult patients with histiocytic neoplasms.

2 DOSAGE AND ADMINISTRATION Confirm the presence of BRAF V600E or V600K mutation in tumor specimens prior to initiation of COTELLIC with vemurafenib for patients with melanoma. ( 2.1 ) The recommended dose is 60 mg orally once daily for the first 21 days of each 28-day cycle until disease progression or unacceptable toxicity. Take COTELLIC with or without food. ( 2.2 ) 2.1 Patient Selection for Treatment of Melanoma Confirm the presence of BRAF V600E or V600K mutation in tumor specimens prior to initiation of treatment with COTELLIC with vemurafenib. Information on FDA-approved tests for the detection of BRAF V600 mutations in melanoma is available at: http://www.fda.gov/CompanionDiagnostics . 2.2 Recommended Dosage The recommended dosage regimen of COTELLIC is 60 mg (three 20 mg tablets) orally taken once daily for the first 21 days of each 28-day cycle until disease progression or unacceptable toxicity [see Clinical Studies (14) ] . Take COTELLIC with or without food [see Clinical Pharmacology (12.3) ] . If a dose of COTELLIC is missed or if vomiting occurs when the dose is taken, resume dosing with the next scheduled dose. 2.3 Dose Modifications Concurrent CYP3A Inhibitors Do not take strong or moderate CYP3A inhibitors while taking COTELLIC. If concurrent short term (14 days or less) use of moderate CYP3A inhibitors is unavoidable for patients who are taking COTELLIC 60 mg, reduce COTELLIC dose to 20 mg. After discontinuation of a moderate CYP3A inhibitor, resume previous dose of COTELLIC 60 mg [see Drug Interactions (7.1) and Clinical Pharmacology (12.3) ] . Use an alternative to a strong or moderate CYP3A inhibitor in patients who are taking a reduced dose of COTELLIC (40 or 20 mg daily) [see Drug Interactions (7.1) and Clinical Pharmacology (12.3) ] . Adverse Reactions Review the Full Prescribing Information for vemurafenib for recommended dose modifications. Table 1. Recommended Dose Reductions for COTELLIC First Dose Reduction 40 mg orally once daily Second Dose Reduction 20 mg orally once daily Subsequent Modification Permanently discontinue COTELLIC if unable to tolerate 20 mg orally once daily Table 2. Recommended Dose Modifications for COTELLIC for Adverse Reactions Severity of Adverse Reaction National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0 (NCI CTCAE v4.0) Dose Modification for COTELLIC New Primary Malignancies (cutaneous and non-cutaneous) No dose modification is required. Hemorrhage Grade 3 Withhold COTELLIC for up to 4 weeks. If improved to Grade 0 or 1, resume at the next lower dose level. If not improved within 4 weeks, permanently discontinue. Grade 4 Permanently discontinue. Cardiomyopathy Asymptomatic, absolute decrease in LVEF from baseline of greater than 10% and less than institutional lower limit of normal (LLN) Withhold COTELLIC for 2 weeks; repeat LVEF. Resume at next lower dose if all of the following are present: LVEF is at or above LLN and Absolute decrease from baseline LVEF is 10% or less. Permanently discontinue if any of the following are present: LVEF is less than LLN or Absolute decrease from baseline LVEF is more than 10%. Symptomatic LVEF decrease from baseline Withhold COTELLIC for up to 4 weeks, repeat LVEF. Resume at next lower dose if all of the following are present: Symptoms resolve and LVEF is at or above LLN and Absolute decrease from baseline LVEF is 10% or less. Permanently discontinue if any of the following are present: Symptoms persist, or LVEF is less than LLN, or Absolute decrease from baseline LVEF is more than 10%. Dermatologic Reactions Grade 2 (intolerable), Grade 3 or 4 Withhold or reduce dose. Serous Retinopathy or Retinal Vein Occlusion Serous retinopathy Withhold COTELLIC for up to 4 weeks. If signs and symptoms improve, resume at the next lower dose level. If not improved or symptoms recur at the lower dose within 4 weeks, permanently discontinue. Retinal vein occlusion Permanently discontinue COTELLIC. Liver Laboratory Abnormalities and Hepatotoxicity First occurrence Grade 4 Withhold COTELLIC for up to 4 weeks. If improved to Grade 0 or 1, then resume at the next lower dose level. If not improved to Grade 0 or 1 within 4 weeks, permanently discontinue. Recurrent Grade 4 Permanently discontinue COTELLIC. Rhabdomyolysis and Creatine Phosphokinase (CPK) elevations Grade 4 CPK elevation Any CPK elevation and myalgia Withhold COTELLIC for up to 4 weeks. If improved to Grade 3 or lower, resume at the next lower dose level. If not improved within 4 weeks, permanently discontinue. Photosensitivity Grade 2 (intolerable), Grade 3 or Grade 4 Withhold COTELLIC for up to 4 weeks. If improved to Grade 0 or 1, resume at the next lower dose level. If not improved within 4 weeks, permanently discontinue. Other Grade 2 (intolerable) adverse reactions Any Grade 3 adverse reactions Withhold COTELLIC for up to 4 weeks. If improved to Grade 0 or 1, resume at the next lower dose level. If not improved within 4 weeks, permanently

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the label: New Primary Cutaneous Malignancies [see Warnings and Precautions (5.1) ] Hemorrhage [see Warnings and Precautions (5.2) ] Cardiomyopathy [see Warnings and Precautions (5.3) ] Serious Dermatologic Reactions [see Warnings and Precautions (5.4) ] Serous Retinopathy and Retinal Vein Occlusion [see Warnings and Precautions (5.5) ] Hepatotoxicity [see Warnings and Precautions (5.6) ] Rhabdomyolysis [see Warnings and Precautions (5.7) ] Severe Photosensitivity [see Warnings and Precautions (5.8) ] Unresectable or Metastatic Melanoma: Most common adverse reactions for COTELLIC (≥20%) are diarrhea, photosensitivity reaction, nausea, pyrexia, and vomiting. The most common (≥5%) Grade 3-4 laboratory abnormalities are increased GGT, increased CPK, hypophosphatemia, increased ALT, lymphopenia, increased AST, increased alkaline phosphatase, hyponatremia. ( 6.1 ) Histiocytic neoplasms: Most common adverse reactions (≥20%) are acneiform dermatitis, diarrhea, infection, fatigue, nausea, edema, dry skin, maculopapular rash, pruritus, dyspepsia, vomiting, dyspnea and urinary tract infections. The most common (≥5%) grade 3-4 lab abnormalities include: Hyponatremia, increased blood creatine phosphokinase, hypokalemia, increased blood creatinine, increased AST, hypocalcemia, lymphopenia, leukopenia, anemia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Genentech at 1-888-835-2555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials 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. Unresectable or Metastatic Melanoma The safety of COTELLIC was evaluated in Trial 1, a randomized (1:1), double-blind, active-controlled trial in previously untreated patients with BRAF V600 mutation-positive, unresectable or metastatic melanoma [see Clinical Studies (14) ] . All patients received vemurafenib 960 mg twice daily on Days 1–28 and received either COTELLIC 60 mg once daily (n=247) or placebo (n=246) on Days 1–21 of each 28-day treatment cycle until disease progression or unacceptable toxicity. In the COTELLIC plus vemurafenib arm, 66% percent of patients were exposed for greater than 6 months and 24% of patients were exposed for greater than 1 year. Patients with abnormal liver function tests, history of acute coronary syndrome within 6 months, evidence of Class II or greater congestive heart failure (New York Heart Association), active central nervous system lesions, or evidence of retinal pathology were excluded from Trial 1. The demographics and baseline tumor characteristics of patients enrolled in Trial 1 are summarized in Clinical Studies [see Clinical Studies (14) ]. In Trial 1, 15% of patients receiving COTELLIC experienced an adverse reaction that resulted in permanent discontinuation of COTELLIC. The most common adverse reactions resulting in permanent discontinuation were liver laboratory abnormalities defined as increased aspartate aminotransferase (AST) (2.4%), increased gamma glutamyltransferase (GGT) (1.6%) and increased alanine aminotransferase (ALT) (1.6%); rash (1.6%); pyrexia (1.2%); and retinal detachment (2%). Among the 247 patients receiving COTELLIC, adverse reactions led to dose interruption or reductions in 55%. The most common reasons for dose interruptions or reductions of COTELLIC were rash (11%) , diarrhea (9%), chorioretinopathy (7%), pyrexia (6%), vomiting (6%), nausea (5%), and increased creatine phosphokinase (CPK) (4.9%). The most common (≥20%) adverse reactions with COTELLIC were diarrhea, photosensitivity reaction, nausea, pyrexia, and vomiting. Table 3. Incidence of Adverse Drug Reactions Occurring in ≥10% (All Grades) of Unresectable or Metastatic Melanoma Patients Receiving COTELLIC with Vemurafenib and at a Higher Incidence ≥5% for All Grades or ≥2% for Grades 3–4 incidence in patients receiving COTELLIC with vemurafenib compared with patients receiving vemurafenib as a single agent than Patients Receiving Vemurafenib in Trial 1 Adverse reactions COTELLIC + Vemurafenib (n=247) Placebo + Vemurafenib (n=246) All Grades NCI CTCAE, v4.0. (%) Grades 3–4 (%) All Grades (%) Grades 3–4 (%) GASTROINTESTINAL DISORDERS Diarrhea 60 6 31 1 Nausea 41 1 25 1 Vomiting 24 1 13 1 Stomatitis Includes stomatitis, aphthous stomatitis, mouth ulceration, and mucosal inflammation 14 1 8 0 SKIN AND SUBCUTANEOUS TISSUE DISORDERS Photosensitivity reaction Includes solar dermatitis, sunburn, photosensitivity reaction 46 4 35 0 Acneiform dermatitis 16 2 11 1 GENERAL DISORDERS AND ADMINISTRATION SITE CONDITIONS Pyrexia 28 2 23 0 Chills 10 0 5 0 VASCULAR DISORDERS Hypertension 15 4 8 2 Hemorrhage Includes hemorrhage, rectal hemorrhage, melena, hemorrhoidal hemorrhage, gas

7 DRUG INTERACTIONS Avoid concomitant administration of COTELLIC with strong or moderate CYP3A inducers or inhibitors. ( 2.3 , 7.1 , 7.2 ) 7.1 Effect of Strong or Moderate CYP3A Inhibitors on COTELLIC Coadministration of COTELLIC with itraconazole (a strong CYP3A4 inhibitor) increased cobimetinib systemic exposure by 6.7-fold. Avoid concurrent use of COTELLIC and strong or moderate CYP3A inhibitors. If concurrent short term (14 days or less) use of moderate CYP3A inhibitors including certain antibiotics (e.g., erythromycin, ciprofloxacin) is unavoidable for patients who are taking COTELLIC 60 mg, reduce COTELLIC dose to 20 mg. After discontinuation of a moderate CYP3A inhibitor, resume COTELLIC at the previous dose [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3) ] . Use an alternative to a strong or moderate CYP3A inhibitor in patients who are taking a reduced dose of COTELLIC (40 or 20 mg daily) [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3) ] . 7.2 Effect of Strong or Moderate CYP3A Inducers on COTELLIC Coadministration of COTELLIC with a strong CYP3A inducer may decrease cobimetinib systemic exposure by more than 80% and reduce its efficacy. Avoid concurrent use of COTELLIC and strong or moderate CYP3A inducers including but not limited to carbamazepine, efavirenz, phenytoin, rifampin, and St. John's Wort [see Clinical Pharmacology (12.3) ] .