Dear Amy,

We are sending this communication on behalf of Seattle Genetics, to announce the recently added TUKYSA SKU for 150mg, 120 tablets per bottle. TUKYSA is indicated in combination with trastuzumab and capecitabine for treatment of adult patients with advanced unresectable or metastatic HER2-positive breast cancer, including patients with brain metastases, who have received one or more prior anti-HER2-based regimens in the metastatic setting.

The recommended dosage of TUKYSA is 300 mg administered orally twice daily.

Please see Important Safety Information below and click to access the Full Prescribing Information for TUKYSA.




Yellow, caplet shaped
TUC embossed on one
side / 150 on other side

120 count
tablets per


60 count
tablets per


Yellow, round-convex
TUC embossed on one
side / 50 on other side

60 count
tablets per


Additionally, please note that the above NDC and SKU numbers for all three of the Tukysa formulations are already included in the following 5 Drug Compendia databases:
  • First Data Bank
  • Medi-Span
  • Cerner
  • Red Book
  • Gold Standard


Warnings and Precautions
  • Diarrhea – TUKYSA can cause severe diarrhea including dehydration, hypotension, acute kidney injury, and death. In HER2CLIMB, 81% of TUKYSA-treated patients experienced diarrhea: 12% (Grade 3); 0.5% (Grade 4). Median time to onset of diarrhea was 12 days and the median time to resolution was 8 days. Diarrhea led to TUKYSA dose reductions in 4.2% of patients and TUKYSA discontinuation TUKYSA in 1% of patients. Prophylactic use of antidiarrheal treatment was not required on HER2CLIMB.

    If diarrhea occurs, administer antidiarrheal treatment as clinically indicated. Perform diagnostic tests as clinically indicated to exclude other causes of diarrhea. Based on the severity of the diarrhea, interrupt dose, then dose reduce or permanently discontinue TUKYSA and/or capecitabine.
  • Hepatotoxicity – TUKYSA can cause severe hepatotoxicity. In TUKYSA-treated patients in HER2CLIMB, 8% had an ALT increase >5x ULN, 6% had an AST increase >5x ULN, and 1.5% had a bilirubin increase >3x ULN (Grade ≥3). Hepatotoxicity led to TUKYSA dose reduction in 8% of patients and TUKYSA discontinuation in 1.5% of patients.

    Monitor ALT, AST, and bilirubin prior to the start of TUKYSA and every three weeks while on treatment, or as clinically indicated.
  • Embryo-Fetal Toxicity - TUKYSA can cause fetal harm. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential and male patients with female partners of reproductive potential to use effective contraception during TUKYSA treatment and for at least 1 week after the last dose.
Adverse Reactions
Serious adverse reactions occurred in 26% of TUKYSA-treated patients. The most common serious adverse reactions (≥2%) were diarrhea (4%), vomiting (2.5%), nausea (2%), abdominal pain (2%), and seizure (2%). Fatal adverse reactions occurred in 2% of TUKYSA-treated patients including sudden death, sepsis, dehydration, and cardiogenic shock.

Adverse reactions led to treatment discontinuation in 6% of TUKYSA-treated patients; those occurring in ≥1% of patients were hepatotoxicity (1.5%) and diarrhea (1%). Adverse reactions led to dose reduction in 18% of TUKYSA-treated patients; those occurring in ≥2% of patients were hepatotoxicity (8%) and diarrhea (4.2%).

The most common adverse reactions in TUKYSA-treated patients (≥20%) were: diarrhea, palmar-plantar erythrodysaesthesia syndrome, nausea, fatigue, vomiting, stomatitis, decreased appetite, blood bilirubin increased, AST increased, abdominal pain, headache, ALT increased, and rash.

Lab Abnormalities
In HER2CLIMB, Grade ≥3 laboratory abnormalities reported in ≥5% were: phosphate decreased, ALT increased, AST increased, and potassium decreased.

TUKYSA can cause an increase in serum creatinine due to inhibition of renal tubular transport of creatinine without affecting glomerular function. In clinical studies, TUKYSA-treated patients experienced increases in serum creatinine: 11% (Grade 1) and 22% (Grade 2). Among all patients, the mean increase in serum creatinine was 32% within the first 21 days of TUKYSA treatment. The serum creatinine increases persisted throughout treatment and were reversible upon treatment discontinuation. Consider monitoring renal function with alternative markers, which are not based on creatinine, to determine whether renal function is impaired.

Drug Interactions
  • Strong CYP3A/CYP2C8 inducers: Concomitant use may decrease TUKYSA activity. Avoid concomitant use with TUKYSA.
  • Strong CYP2C8 inhibitors: Concomitant use may increase risk of TUKYSA toxicity. Avoid concomitant use with TUKYSA.
  • Sensitive CYP3A substrates: Concomitant use may increase the toxicity of sensitive CYP3A substrates. Avoid concomitant use with TUKYSA. If concomitant use is unavoidable, consider reducing the dosage of sensitive CYP3A substrates where minimal concentration change may lead to serious or life-threatening toxicity, and consider increased monitoring.
  • P-gp substrates: Concomitant use may increase the toxicity of P-gp substrates. Consider reducing the dosage of P-gp substrates, such as digoxin, where minimal concentration change may lead to serious or life-threatening toxicity.
Use in Specific Populations
  • Lactation: Advise women not to breastfeed while taking TUKYSA and for at least 1 week after the last dose.
  • Hepatic Impairment: Reduce the dose of TUKYSA for patients with severe (Child-Pugh C) hepatic impairment.

For questions regarding TUKYSA, please contact Seattle Genetics Medical Information at 1-855-4SEAGEN (1-855-473-2436) or

For more information, please visit


ION Solutions 

1. TUKYSA [prescribing information]. Bothell, WA: Seattle Genetics, Inc. April 2020. [link]
2. US Food and Drug Administration. National Drug Code Background Information. Accessed April 1, 2020.

TUKYSA and its logo, SeaGen Secure and its logo, and Seattle Genetics and
 are US registered trademarks of Seattle Genetics, Inc.
TUKYSA is manufactured and marketed by Seattle Genetics, Inc., Bothell, WA.
© 2020 Seattle Genetics, Inc. All rights reserved. US-TUP-20-472-MT
This email was sent to because you have an account with or are a valued partner of ION Solutions. If you no longer wish to receive these types of emails, please click here to unsubscribe or update your email preferences.
AmerisourceBergen - 1300 Morris Dr Chesterbrook PA, 19087
© 2020 ION Solutions. All Rights Reserved.