6 ADVERSE REACTIONS

The following adverse reactions are discussed in greater detail in other sections of the label:

Cardiomyopathy [see Warnings and Precautions (5.1)]
Infusion Reactions [see Warnings and Precautions (5.2)]
Embryo-Fetal Toxicity [see Warnings and Precautions (5.3)]
Pulmonary Toxicity [see Warnings and Precautions (5.4)]
Exacerbation of Chemotherapy-Induced Neutropenia [see Warnings and Precautions (5.5)]

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.

The most common adverse reactions in patients receiving Herceptin in the adjuvant and metastatic breast cancer setting are fever, nausea, vomiting, infusion reactions, diarrhea, infections, increased cough, headache, fatigue, dyspnea, rash, neutropenia, anemia, and myalgia. Adverse reactions requiring interruption or discontinuation of Herceptin treatment include CHF, significant decline in left ventricular cardiac function, severe infusion reactions, and pulmonary toxicity [see Dosage and Administration (2.5)].

In the metastatic gastric cancer setting, the most common adverse reactions (≥ 10%) that were increased (≥ 5% difference) in the Herceptin arm as compared to the chemotherapy alone arm were neutropenia, diarrhea, fatigue, anemia, stomatitis, weight loss, upper respiratory tract infections, fever, thrombocytopenia, mucosal inflammation, nasopharyngitis, and dysgeusia.

The most common adverse reactions which resulted in discontinuation of treatment on the Herceptin-containing arm in the absence of disease progression were infection, diarrhea, and febrile neutropenia.

Adjuvant Breast Cancer

The information below reflects exposure to one-year Herceptin therapy across three randomized, open-label studies, Studies 1, 2, and 3, with (n = 3678) or without (n = 3363) trastuzumab in the adjuvant treatment of breast cancer.

HERA

Table 3 reflects exposure to Herceptin in 1678 patients in HERA; the median treatment duration was 51 weeks and median number of infusions was 18 [see Clinical Studies (14.1)].

Table 3: Adverse Reactions (≥1%) in HERA (All Grades)*
Adverse Reactions	Herceptin (n = 1678) %	Observation (n = 1708) %
* The incidence of Grade 3 or higher adverse reactions was <1% in both arms for each listed term. † Higher level grouping term.
Nervous System
Headache	10	3
Paresthesia	2	0.6
Musculoskeletal
Arthralgia	8	6
Back pain	5	3
Myalgia	4	1
Bone pain	3	2
Muscle spasm	3	0.2
Infections
Nasopharyngitis	8	3
Urinary tract infection	3	0.8
Gastrointestinal
Diarrhea	7	1
Nausea	6	1
Vomiting	3.5	0.6
Constipation	2	1
Dyspepsia	2	0.5
Upper abdominal pain	2	1
General
Pyrexia	6	0.4
Peripheral edema	5	2
Chills	5	0
Asthenia	4.5	2
Influenza-like illness	2	0.2
Respiratory Thoracic Mediastinal
Cough	5	2
Influenza	4	0.5
Dyspnea	3	2
URI	3	1
Rhinitis	2	0.4
Pharyngolaryngeal pain	2	0.5
Sinusitis	2	0.3
Epistaxis	2	0.06
Cardiac
Hypertension	4	2
Dizziness	4	2
Ejection fraction decreased	3.5	0.6
Palpitations	3	0.7
Cardiac arrhythmias†	3	1
Cardiac failure (congestive)	2	0.3
Skin & Subcutaneous Tissue
Rash	4	0.6
Nail disorders	2	0
Pruritus	2	0.6

Clinically relevant adverse reactions in < 1% of patients who received Herceptin in HERA included hypersensitivity (0.6%), cardiac failure (0.5%), cardiac disorder (0.3%), interstitial pneumonitis (0.2%), pulmonary hypertension (0.2%), ventricular disorder (0.2%), autoimmune thyroiditis (0.3%), and sudden death (0.06%).

Adjuvant Treatment of Breast Cancer with Herceptin Beyond One Year

Extending adjuvant treatment beyond one year is not recommended [see Dosage and Administration (2.2)]. In HERA, a comparison of Herceptin administered once every 3 weeks for two years versus one year was performed. The rate of asymptomatic cardiac dysfunction was increased in the 2-year Herceptin compared to the 1-year Herceptin treatment arm (8.1% versus 4.6%, respectively). More patients experienced at least one adverse reaction of Grade 3 or higher in the 2-year Herceptin treatment arm (20.4%) compared with the one-year Herceptin treatment arm (16.3%).

NSABP B31 and NCCTG N9831

The safety data from NSABP B31 and NCCTG N9831 were obtained from 3655 patients, of whom 2000 received Herceptin; the median treatment duration was 51 weeks [see Clinical Studies (14.1)].

In NSABP B31, only Grade 3–5 adverse events, treatment-related Grade 2 events, and Grade 2–5 dyspnea were collected during and for up to 3 months following protocol-specified treatment. The following non-cardiac adverse reactions of Grade 2–5 occurred at an incidence of at least 2% greater among patients receiving Herceptin plus chemotherapy as compared to chemotherapy alone: fatigue (29.5% vs. 22.4%), infection (24.0% vs. 12.8%), hot flashes (17.1% vs. 15%), anemia (12.3% vs. 6.7%), dyspnea (11.8% vs. 4.6%), rash/desquamation (10.9% vs. 7.6%), leukopenia (10.5% vs. 8.4%), neutropenia (6.4% vs. 4.3%), headache (6.2% vs. 3.8%), pain (5.5% vs. 3%), edema (4.7% vs. 2.7%), and insomnia (4.3% vs. 1.5%). The majority of these events were Grade 2 in severity.

In NCCTG N9831, data collection was limited to the following investigator-attributed treatment-related adverse reactions: NCI-CTC Grade 4 and 5 hematologic toxicities, Grade 3–5 non-hematologic toxicities, selected Grade 2–5 toxicities associated with taxanes (myalgia, arthralgias, nail changes, motor neuropathy, and sensory neuropathy) and Grade 1–5 cardiac toxicities occurring during chemotherapy and/or Herceptin treatment. The following non-cardiac adverse reactions of Grade 2–5 occurred at an incidence of at least 2% greater among patients receiving Herceptin plus chemotherapy as compared to chemotherapy alone: arthralgia (12.2% vs. 9.1%), nail changes (11.5% vs. 6.8%), dyspnea (2.4% vs. 0.2%), and diarrhea (2.2% vs. 0%). The majority of these events were Grade 2 in severity.

BCIRG006

Safety data from BCIRG006 reflect exposure to Herceptin as part of an adjuvant treatment regimen from 2124 patients receiving at least one dose of study treatment [AC-TH: n = 1068; TCH: n = 1056]. The overall median treatment duration was 54 weeks in both the AC-TH and TCH arms. The median number of infusions was 26 in the AC-TH arm and 30 in the TCH arm, including weekly infusions during the chemotherapy phase and once every three week dosing in the monotherapy period [see Clinical Studies (14.1)]. In BCIRG006, the toxicity profile was similar to that reported in Studies NSABP B31, NCCTG N9831, and HERA with the exception of a lower incidence of CHF in the TCH arm.

Metastatic Breast Cancer Studies

The safety of Herceptin was evaluated in one randomized, open-label study (H0648g) of chemotherapy with (n = 235) or without (n = 234) intravenous trastuzumab in patients with metastatic breast cancerand in one single-arm study (H0649g); in patients with metastatic breast cancer (n=222) [see Clinical Studies (14.1)]. Patients received 4 mg/kg initial dose of Herceptin followed by 2 mg/kg weekly. In H0648g, 58% of patients received Herceptin for ≥ 6 months and 9% received Herceptin ≥ 12 months, respectively. In H0649g, 31% of patients received Herceptin for ≥ 6 months and 16% received Herceptin for ≥ 12 months, respectively.

Table 4 shows the adverse reactions (≥ 5%) in patients from H0648g and H0649g.

Table 4: Adverse Reactions ≥ (5%) in the Herceptin Arms in H0648g and H0649g
	Herceptin* n = 352 %	Herceptin + Paclitaxel n = 91 %	Paclitaxel n = 95 %	Herceptin + AC† n = 143 %	AC† n = 135 %
* Data for Herceptin single agent were from 4 studies, including 213 patients from H0649g. † Anthracycline (doxorubicin or epirubicin) and cyclophosphamide.
General
Pain	47	61	62	57	42
Asthenia	42	62	57	54	55
Fever	36	49	23	56	34
Chills	32	41	4	35	11
Headache	26	36	28	44	31
Abdominal pain	22	34	22	23	18
Back pain	22	34	30	27	15
Infection	20	47	27	47	31
Flu syndrome	10	12	5	12	6
Accidental injury	6	13	3	9	4
Allergic reaction	3	8	2	4	2
Gastrointestinal
Nausea	33	51	9	76	77
Diarrhea	25	45	29	45	26
Vomiting	23	37	28	53	49
Anorexia	14	24	16	31	26
Nausea and vomiting	8	14	11	18	9
Respiratory
Cough increased	26	41	22	43	29
Dyspnea	22	27	26	42	25
Rhinitis	14	22	5	22	16
Pharyngitis	12	22	14	30	18
Sinusitis	9	21	7	13	6
Skin
Rash	18	38	18	27	17
Herpes simplex	2	12	3	7	9
Acne	2	11	3	3	< 1
Nervous
Insomnia	14	25	13	29	15
Dizziness	13	22	24	24	18
Paresthesia	9	48	39	17	11
Depression	6	12	13	20	12
Peripheral neuritis	2	23	16	2	2
Neuropathy	1	13	5	4	4
Metabolic
Peripheral edema	10	22	20	20	17
Edema	8	10	8	11	5
Cardiovascular
Congestive heart failure	7	11	1	28	7
Tachycardia	5	12	4	10	5
Musculoskeletal
Bone pain	7	24	18	7	7
Arthralgia	6	37	21	8	9
Urogenital
Urinary tract infection	5	18	14	13	7
Blood and Lymphatic
Anemia	4	14	9	36	26
Leukopenia	3	24	17	52	34

Metastatic Gastric Cancer

The safety of Herceptin was evaluated in patients with previously untreated for metastatic gastric or gastroesophageal junction adenocarcinoma in an open label, multi-center trial (ToGA) [see Clinical Studies (14.3)]. Patients were randomized (1:1) to receive Herceptin in combination with cisplatin and a fluoropyrimidine (FC+H) (n=294) or chemotherapy alone (FC) (n=290) Patients in the Herceptin plus chemotherapy arm received Herceptin 8 mg/kg administered on Day 1 (prior to chemotherapy) followed by 6 mg/kg every 21 days until disease progression. Cisplatin was administered at 80 mg/m2 on Day 1 and the fluoropyrimidine was administered as either capecitabine 1000 mg/m2 orally twice a day on Days 1–14 or 5-fluorouracil 800 mg/m2/day as a continuous intravenous infusion Days 1 through 5. Chemotherapy was administered for six 21-day cycles. Median duration of Herceptin treatment was 21 weeks and the median number of Herceptin infusions administered was eight.

Table 5: Adverse Reactions (All Grades ≥ 5% or Grade 3-4 ≥ 1% between Arms) in ToGA
Adverse Reactions	Herceptin +FC (N = 294) %		FC (N = 290) %
	All Grades	Grades 3-4	All Grades	Grades 3-4
Investigations
Neutropenia	78	34	73	29
Hypokalemia	28	10	24	6
Anemia	28	12	21	10
Thrombocytopenia	16	5	11	3
Blood and Lymphatic System Disorders
Febrile Neutropenia	—	5	—	3
Gastrointestinal Disorders
Diarrhea	37	9	28	4
Stomatitis	24	1	15	2
Dysphagia	6	2	3	< 1
General
Fatigue	35	4	28	2
Fever	18	1	12	0
Mucosal Inflammation	13	2	6	1
Chills	8	< 1	0	0
Metabolism and Nutrition Disorders
Weight Decrease	23	2	14	2
Infections and Infestations
Upper Respiratory Tract Infections	19	0	10	0
Nasopharyngitis	13	0	6	0
Renal and Urinary Disorders
Renal Failure and Impairment	18	3	15	2
Nervous System Disorders
Dysgeusia	10	0	5	0

The following subsections provide additional detail regarding adverse reactions observed in clinical trials of adjuvant breast cancer, metastatic breast cancer, metastatic gastric cancer, or post-marketing experience.

Cardiomyopathy

Serial measurement of cardiac function (LVEF) was obtained in clinical trials in the adjuvant treatment of breast cancer. In HERA, the median duration of follow-up was 12.6 months (12.4 months in the observation arm; 12.6 months in the 1-year Herceptin arm); and in NSABP B31 and NCCTG N9831, 7.9 years in the AC-T arm, 8.3 years in the AC-TH arm. Following initiation of Herceptin therapy, the incidence of new-onset dose-limiting myocardial dysfunction was higher among patients receiving Herceptin and paclitaxel as compared to those receiving paclitaxel alone in NSABP B31 and NCCTG N9831, and in patients receiving one-year Herceptin monotherapy compared to observation in HERA (see Table 6, Figures 1 and 2). The incidence of new-onset cardiac dysfunction, as measured by LVEF, remained similar when compared to the analysis performed at a median follow-up of 2.0 years in the AC-TH arm. This analysis showed evidence of reversibility of left ventricular dysfunction, with 64.5% of patients who experienced symptomatic CHF in the AC-TH group being asymptomatic at latest follow-up, and 90.3% having full or partial LVEF recovery.

Table 6: Myocardial Dysfunction (by LVEF) in Studies 1, 2, 3 and 4 *
Study and Arm	LVEF < 50% and Decrease from Baseline			LVEF Decrease
Study and Arm	LVEF < 50%	≥ 10% decrease	≥ 16% decrease	< 20% and ≥ 10%	≥ 20%
* For Studies 1, 2 and 3, events are counted from the beginning of Herceptin treatment. For BCIRG006, events are counted from the date of randomization. † NSABP B31 and NCCTG N9831 regimens: doxorubicin and cyclophosphamide followed by paclitaxel (AC→T) or paclitaxel plus Herceptin (AC→TH). ‡ Median duration of follow-up for NSABP B31 and NCCTG N9831 combined was 8.3 years in the AC→TH arm. § Median follow-up duration of 12.6 months in the one-year Herceptin treatment arm. ¶ BCIRG006 regimens: doxorubicin and cyclophosphamide followed by docetaxel (AC→T) or docetaxel plus Herceptin (AC→TH); docetaxel and carboplatin plus Herceptin (TCH).
Studies 1 & 2†,‡
AC→TH (n = 1856)	23.1% (428)	18.5% (344)	11.2% (208)	37.9% (703)	8.9% (166)
AC→T (n = 1170)	11.7% (137)	7.0% (82)	3.0% (35)	22.1% (259)	3.4% (40)
HERA§
Herceptin (n = 1678)	8.6% (144)	7.0% (118)	3.8% (64)	22.4% (376)	3.5% (59)
Observation (n = 1708)	2.7% (46)	2.0% (35)	1.2% (20)	11.9% (204)	1.2% (21)
BCIRG006¶
TCH (n = 1056)	8.5% (90)	5.9% (62)	3.3% (35)	34.5% (364)	6.3% (67)
AC→TH (n = 1068)	17% (182)	13.3% (142)	9.8% (105)	44.3% (473)	13.2% (141)
AC→T (n = 1050)	9.5% (100)	6.6% (69)	3.3% (35)	34% (357)	5.5% (58)

Figure 1
NSABP B31 and NCCTG N9831: Cumulative Incidence of Time to First LVEF
Decline of ≥ 10 Percentage Points from Baseline and to Below 50% with Death as a Competing Risk Event

Time 0 is initiation of paclitaxel or Herceptin + paclitaxel therapy.

Figure 2
HERA: Cumulative Incidence of Time to First LVEF
Decline of ≥ 10 Percentage Points from Baseline and to Below 50% with Death as a Competing Risk Event

Time 0 is the date of randomization.

Figure 3
BCIRG006: Cumulative Incidence of Time to First LVEF
Decline of ≥ 10 Percentage Points from Baseline and to Below 50% with Death as a Competing Risk Event

Time 0 is the date of randomization.

The incidence of congestive heart failure among patients in the metastatic breast cancer trials was classified for severity using the New York Heart Association classification system (I–IV, where IV is the most severe level of cardiac failure) (see Table 2). In the metastatic breast cancer trials, the probability of cardiac dysfunction was highest in patients who received Herceptin concurrently with anthracyclines.

In ToGA, 5% of patients in the Herceptin plus chemotherapy arm compared to 1.1% of patients in the chemotherapy alone arm had LVEF value below 50% with a ≥ 10% absolute decrease in LVEF from pretreatment values.

Infusion Reactions

During the first infusion with Herceptin, the symptoms most commonly reported were chills and fever, occurring in approximately 40% of patients in clinical trials. Symptoms were treated with acetaminophen, diphenhydramine, and meperidine (with or without reduction in the rate of Herceptin infusion); permanent discontinuation of Herceptin for infusion reactions was required in < 1% of patients. Other signs and/or symptoms may include nausea, vomiting, pain (in some cases at tumor sites), rigors, headache, dizziness, dyspnea, hypotension, elevated blood pressure, rash, and asthenia. Infusion reactions occurred in 21% and 35% of patients, and were severe in 1.4% and 9% of patients, on second or subsequent Herceptin infusions administered as monotherapy or in combination with chemotherapy, respectively. In the post-marketing setting, severe infusion reactions, including hypersensitivity, anaphylaxis, and angioedema have been reported.

Anemia

In randomized controlled clinical trials, the overall incidence of anemia (30% vs. 21% [H0648g]), of selected NCI-CTC Grade 2–5 anemia (12.3% vs. 6.7% [NSABP B31]), and of anemia requiring transfusions (0.1% vs. 0 patients [NCCTG N9831]) were increased in patients receiving Herceptin and chemotherapy compared with those receiving chemotherapy alone. Following the administration of Herceptin as a single agent (H0649g), the incidence of NCI-CTC Grade 3 anemia was < 1%. In ToGA (metastatic gastric cancer), on the Herceptin containing arm as compared to the chemotherapy alone arm, the overall incidence of anemia was 28% compared to 21% and of NCI- CTC Grade 3/4 anemia was 12.2% compared to 10.3%.

Neutropenia

In randomized controlled clinical trials in the adjuvant setting, the incidence of selected NCI-CTC Grade 4–5 neutropenia (1.7% vs. 0.8% [NCCTG N9831]) and of selected Grade 2–5 neutropenia (6.4% vs. 4.3% [NSABP B31]) were increased in patients receiving Herceptin and chemotherapy compared with those receiving chemotherapy alone. In a randomized, controlled trial in patients with metastatic breast cancer, the incidences of NCI-CTC Grade 3/4 neutropenia (32% vs. 22%) and of febrile neutropenia (23% vs. 17%) were also increased in patients randomized to Herceptin in combination with myelosuppressive chemotherapy as compared to chemotherapy alone. In ToGA (metastatic gastric cancer) on the Herceptin containing arm as compared to the chemotherapy alone arm, the incidence of NCI-CTC Grade 3/4 neutropenia was 36.8% compared to 28.9%; febrile neutropenia 5.1% compared to 2.8%.

Infection

The overall incidences of infection (46% vs. 30% [H0648g]), of selected NCI-CTC Grade 2–5 infection/febrile neutropenia (24.3% vs. 13.4% [NSABP B31]) and of selected Grade 3–5 infection/febrile neutropenia (2.9% vs. 1.4% [NCCTG N9831]) were higher in patients receiving Herceptin and chemotherapy compared with those receiving chemotherapy alone. The most common site of infections in the adjuvant setting involved the upper respiratory tract, skin, and urinary tract.

In BCIRG006, the overall incidence of infection was higher with the addition of Herceptin to AC-T but not to TCH [44% (AC-TH), 37% (TCH), 38% (AC-T)]. The incidences of NCI-CTC Grade 3–4 infection were similar [25% (AC-TH), 21% (TCH), 23% (AC-T)] across the three arms.

In a randomized, controlled trial in treatment of metastatic breast cancer, the reported incidence of febrile neutropenia was higher (23% vs. 17%) in patients receiving Herceptin in combination with myelosuppressive chemotherapy as compared to chemotherapy alone.

Pulmonary Toxicity

Adjuvant Breast Cancer

Among women receiving adjuvant therapy for breast cancer, the incidence of selected NCI-CTC Grade 2–5 pulmonary toxicity (14.3% vs. 5.4% [NSABP B31]) and of selected NCI-CTC Grade 3–5 pulmonary toxicity and spontaneous reported Grade 2 dyspnea (3.4% vs. 0.9% [NCCTG N9831]) was higher in patients receiving Herceptin and chemotherapy compared with chemotherapy alone. The most common pulmonary toxicity was dyspnea (NCI-CTC Grade 2–5: 11.8% vs. 4.6% [NSABP B31]; NCI-CTC Grade 2–5: 2.4% vs. 0.2% [NCCTG N9831]).

Pneumonitis/pulmonary infiltrates occurred in 0.7% of patients receiving Herceptin compared with 0.3% of those receiving chemotherapy alone. Fatal respiratory failure occurred in 3 patients receiving Herceptin, one as a component of multi-organ system failure, as compared to 1 patient receiving chemotherapy alone.

In HERA, there were 4 cases of interstitial pneumonitis in the one-year Herceptin treatment arm compared to none in the observation arm at a median follow-up duration of 12.6 months.

Metastatic Breast Cancer

Among women receiving Herceptin for treatment of metastatic breast cancer, the incidence of pulmonary toxicity was also increased. Pulmonary adverse events have been reported in the post-marketing experience as part of the symptom complex of infusion reactions. Pulmonary events include bronchospasm, hypoxia, dyspnea, pulmonary infiltrates, pleural effusions, non-cardiogenic pulmonary edema, and acute respiratory distress syndrome. For a detailed description, see Warnings and Precautions (5.4).

Thrombosis/Embolism

In 4 randomized, controlled clinical trials, the incidence of thrombotic adverse events was higher in patients receiving Herceptin and chemotherapy compared to chemotherapy alone in three studies (2.6% vs. 1.5% [NSABP B31], 2.5% and 3.7% vs. 2.2% [BCIRG006] and 2.1% vs. 0% [H0648g]).

Diarrhea

Among women receiving adjuvant therapy for breast cancer, the incidence of NCI-CTC Grade 2–5 diarrhea (6.7% vs. 5.4% [NSABP B31]) and of NCI-CTC Grade 3–5 diarrhea (2.2% vs. 0% [NCCTG N9831]), and of Grade 1–4 diarrhea (7% vs. 1% [HERA; one-year Herceptin treatment at 12.6 months median duration of follow-up]) were higher in patients receiving Herceptin as compared to controls. In BCIRG006, the incidence of Grade 3–4 diarrhea was higher [5.7% AC-TH, 5.5% TCH vs. 3.0% AC-T] and of Grade 1–4 was higher [51% AC-TH, 63% TCH vs. 43% AC-T] among women receiving Herceptin. Of patients receiving Herceptin as a single agent for the treatment of metastatic breast cancer, 25% experienced diarrhea. An increased incidence of diarrhea was observed in patients receiving Herceptin in combination with chemotherapy for treatment of metastatic breast cancer.

Renal Toxicity

In ToGA (metastatic gastric cancer) on the Herceptin-containing arm as compared to the chemotherapy alone arm the incidence of renal impairment was 18% compared to 14.5%. Severe (Grade 3/4) renal failure was 2.7% on the Herceptin-containing arm compared to 1.7% on the chemotherapy only arm. Treatment discontinuation for renal insufficiency/failure was 2% on the Herceptin-containing arm and 0.3% on the chemotherapy only arm.

In the post-marketing setting, rare cases of nephrotic syndrome with pathologic evidence of glomerulopathy have been reported. The time to onset ranged from 4 months to approximately 18 months from initiation of Herceptin therapy. Pathologic findings included membranous glomerulonephritis, focal glomerulosclerosis, and fibrillary glomerulonephritis. Complications included volume overload and congestive heart failure.

6.2 Post-Marketing Experience

The following adverse reactions have been identified during post-approval use of Herceptin. 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.

Infusion reaction [see Warnings and Precautions (5.2)]
Oligohydramnios or oligohydramnios sequence, including pulmonary hypoplasia, skeletal abnormalities, and neonatal death [see Warnings and Precautions (5.3)]
Glomerulopathy [see Adverse Reactions (6.1)]
Immune thrombocytopenia
Tumor lysis syndrome (TLS): Cases of possible TLS have been reported in patients treated with Herceptin. Patients with significant tumor burden (e.g. bulky metastases) may be at a higher risk. Patients could present with hyperuricemia, hyperphosphatemia, and acute renal failure which may represent possible TLS. Providers should consider additional monitoring and/or treatment as clinically indicated.