In combination with trastuzumab + capecitabine

TUKYSA DELIVERED SUPERIOR RESULTS IN PRIMARY ANALYSIS OF HER2CLIMB1


In patients treated with TUKYSA (tucatinib) + trastuzumab + capecitabine (TUKYSA arm) vs those treated with placebo + trastuzumab + capecitabine (control arm):

Progression-free survival

  • Primary endpoint: Median PFS: 7.8 months (95% CI: 7.5-9.6) in the TUKYSA arm vs 5.6 months (95% CI: 4.2-7.1) in the control arm; HR = 0.54 (95% CI: 0.42-0.71); P <0.000011*
  • Secondary endpoint: Median PFS in patients with brain metastases: 7.6 months (95% CI: 6.2-9.5) in the TUKYSA arm vs 5.4 months (95% CI: 4.1-5.7) in the control arm; HR = 0.48 (95% CI: 0.34-0.69); P <0.000011

Click here to see KM curves.

*Data from the first 480 patients.1
CI = confidence interval; HR = hazard ratio; KM = Kaplan-Meier; PFS = progression-free survival.

 

HER2CLIMB: Median overall survival at primary and exploratory follow-up analyses1,2

Results of this prespecified exploratory analysis are descriptive but not conclusive, are not controlled for type 1 error, and should be interpreted with caution. Data cutoff for follow-up analysis was February 8, 2021.2

OS in the total population with updated prespecified data (N=612)1,2

TUKYSA® (tucatinib) tablets: Kaplan-Meier estimates of overall survival (OS) in HER2CLIMB trial

Efficacy results were consistent across patient subgroups defined by stratification factors and hormone receptor status.1

ECOG = Eastern Cooperative Oncology Group; ER = estrogen receptor; PR = progesterone receptor.

  • These analyses are considered exploratory. No adjustments were made for multiple comparisons in the subgroup analyses
  • Small patient numbers can be a limitation of subgroup analyses. These analyses are not intended to demonstrate efficacy in particular subgroups

Median OS in patients with brain metastases (n = 291)4

  • 21.6 months (95% CI: 18.1-28.5) in the TUKYSA arm vs 12.5 months (95% CI: 11.2-16.9) in the control arm; HR = 0.60 (95% CI: 0.44-0.81); exploratory follow-up analysis

Median OS in patients with visceral metastases (n = 455)5

  • 21.6 months (95% CI: 18.1-25.6) in the TUKYSA arm vs 16.9 months (95% CI: 12.3-19.4) in the control arm; HR = 0.70 (95% CI: 0.55-0.89); exploratory follow-up analysis
Review safety data for 2-year follow-up


OS = overall survival.

HER2CLIMB: Exploratory follow-up analyses

HER2CLIMB: Time to new brain lesions or death at exploratory follow-up analysis4

  • Results of this exploratory analysis are descriptive but not conclusive, and they are not controlled for type 1 error. Due to a high rate of censoring of patients owing to extra-CNS progression, results should be interpreted with caution. Data cutoff for follow-up analysis was February 8, 20214
  • Brain lesion development was detected through use of brain MRI scans. All patients received a baseline brain MRI scan. Only patients with a history or baseline presence of brain metastases were scanned at regular intervals throughout the trial. Unless clinically indicated, patients with no history of brain metastasis were not routinely scanned. This depiction is limited to patients who were re-scanned through the trial7

Time from randomization to new brain lesion development as the first site of progression per investigator assessment or death in patients with or without brain metastases at baseline (N = 612)4
TUKYSA® (tucatinib) tablets: Kaplan-Meier estimates of time from randomization to new brain lesion development or death.

EXPLORATORY ANALYSIS
HR = 0.55 (95% CI: 0.36-0.85)
Reduction in risk of new brain lesions or death: 45%

MRI = magnetic resonance imaging; NE = not estimable.

Results of this post-hoc, exploratory analysis are descriptive, but they are not conclusive, are not controlled for type 1 error, and should be interpreted with caution. Data cutoff for follow-up analysis was February 8, 2021.4

CNS-PFS in patients with brain metastases at baseline (n = 291)4,8*

TUKYSA® (tucatinib) tablets: Kaplan-Meier estimates of CNS-PFS in patients with brain metastases

EXPLORATORY ANALYSIS
HR = 0.39 (95% Cl: 0.27-0.56)

NUMBER OF EVENTS
TUKYSA arm: 94/198
Control arm: 48/93

*CNS-PFS was defined as the time from randomization to disease progression in the brain by investigator assessment or death. Progression in the brain was evaluated by applying RECIST, version 1.1, to assess brain lesions in isolation from other organs.4
The results are estimates (not exact numbers). Due to a high rate of censoring patients owing to extra-CNS progression, results should be interpreted with caution.
 CNS = central nervous system; ORR = objective response rate.

Results of this post-hoc, exploratory analysis are descriptive, but they are not conclusive, are not controlled for type 1 error, and should be interpreted with caution. Data cutoff for follow-up analysis was February 8, 2021.4

ORR-IC in patients with brain metastases at baseline that were measurable for response (n = 75)4,9*

Bar chart: Intracranial Overall Response Rate (ORR-IC) in patients with measurable brain metastases

*Intracranial response was assessed by investigators according to RECIST, version 1.1, in patients with measurable intracranial lesions at baseline.4
 CR = complete response; ORR-IC = intracranial objective response rate; PR = partial response; RECIST = Response Evaluation Criteria in Solid Tumors.


HER2CLIMB: Confirmed tumor response and time to response1,10

TUKYSA® (tucatinib) tablets: rates of confirmed ORR and Median time to response in HER2CLIMBTUKYSA® (tucatinib) tablets: rates of confirmed ORR and Median time to response in HER2CLIMB

HER2CLIMB exploratory analysis: OS in patients with stable disease as best overall response (n = 343)6 *

Results of this exploratory subgroup analysis are descriptive but not conclusive, are not controlled for type 1 error, and should be interpreted with caution.

  • Median OS: 21.8 months (95% CI: 18.1-NE) in the TUKYSA arm vs 15.2 months (95% CI: 12.0-20.0) in the control arm; HR = 0.60 (95% CI: 0.41-0.88)6
  • Number of events: 65/217 in the TUKYSA arm vs 53/126 in the control arm
  • Stable disease rates in HER2CLIMB11:
  • 45.6% (155/340) in the TUKYSA arm
  • 58.5% (100/171) in the control arm

*Analysis included patients in the total population whose confirmed best overall response by BICR was classified as one of the following: SD or non-CR/non-PD.6
SD was defined using RECIST, version 1.1, as neither sufficient shrinkage to qualify as a PR (PR was defined as ≥30% decrease) nor sufficient increase to qualify as PD (PD was defined as ≥20% increase).11,12

BICR = blinded independent central review; PD = progressive disease; SD = stable disease.

 


HER2CLIMB: PFS in patients with and without brain metastases1,2

In combination with trastuzumab and capecitabine

TUKYSA significantly reduced the risk of disease progression or death1

PFS per BICR in the first 480 patients randomized1

TUKYSA® (tucatinib) tablets: Kaplan-Meier estimates of progression free survival (PFS) from the HER2CLIMB trial

PRIMARY ENDPOINT
HR = 0.54 (95% CI: 0.42-0.71)
P <0.00001

NUMBER OF EVENTS
TUKYSA arm: 178/320
Control arm: 97/160

In combination with trastuzumab and capecitabine

TUKYSA extended PFS in patients with brain metastases1

PFS per BICR in patients with brain metastases at baseline (n = 291)1,3*

TUKYSA® (tucatinib) tablets: Kaplan-Meier estimates of progression free survival (PFS) in patients with brain metastases

SECONDARY ENDPOINT
HR = 0.48 (95% CI: 0.34-0.69)
P <0.00001

NUMBER OF EVENTS
TUKYSA arm: 106/198
Control arm: 51/93

*Analysis includes patients with history or presence of parenchymal brain metastases at baseline, including target and nontarget lesions. Analysis does not include patients with dural lesions only.1

HER2CLIMB exploratory analysis: PFS in patients without brain metastases11

Results of this exploratory subgroup analysis are descriptive but not conclusive, are not controlled for type 1 error, and should be interpreted with caution.

PFS per BICR in patients without brain metastases (n = 319)

TUKYSA® (tucatinib) tablets: Kaplan-Meier estimates of progression free survival (PFS) in patients without brain metastases

EXPLORATORY ANALYSIS
HR = 0.57 (95% CI: 0.41-0.80)

NUMBER OF EVENTS
TUKYSA arm: 91/211
Control arm: 60/108

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Next: Review the safety profile

Important Safety Information

Warnings and Precautions

  • Diarrhea: TUKYSA can cause severe diarrhea including dehydration, hypotension, acute kidney injury, and death. 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.

    In HER2CLIMB, when TUKYSA was given in combination with trastuzumab and capecitabine, 81% of patients who received TUKYSA experienced diarrhea, including 0.5% with Grade 4 and 12% with Grade 3. Both patients who developed Grade 4 diarrhea subsequently died, with diarrhea as a contributor to death. Median time to onset of the first episode of diarrhea was 12 days and the median time to resolution was 8 days. Diarrhea led to TUKYSA dose reductions in 6% of patients and TUKYSA discontinuation in 1% of patients. Prophylactic use of antidiarrheal treatment was not required on HER2CLIMB.

  • Hepatotoxicity: TUKYSA can cause severe hepatotoxicity. Monitor ALT, AST, and bilirubin prior to starting TUKYSA, every 3 weeks during treatment, and as clinically indicated. Based on the severity of hepatotoxicity, interrupt dose, then dose reduce or permanently discontinue TUKYSA.

    In HER2CLIMB, 8% of patients who received TUKYSA had an ALT increase >5 × ULN, 6% had an AST increase >5 × ULN, and 1.5% had a bilirubin increase >3 × ULN (Grade ≥3). Hepatotoxicity led to TUKYSA dose reductions in 8% of patients and TUKYSA discontinuation in 1.5% of patients.

  • 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 1 week after the last dose.

Adverse Reactions

In HER2CLIMB, serious adverse reactions occurred in 26% of patients who received TUKYSA; the most common (in ≥2% of patients) were diarrhea (4%), vomiting (2.5%), nausea (2%), abdominal pain (2%), and seizure (2%). Fatal adverse reactions occurred in 2% of patients who received TUKYSA including sudden death, sepsis, dehydration, and cardiogenic shock.

Adverse reactions led to treatment discontinuation in 6% of patients who received TUKYSA; the most common (in ≥1% of patients) were hepatotoxicity (1.5%) and diarrhea (1%). Adverse reactions led to dose reduction in 21% of patients who received TUKYSA; the most common (in ≥2% of patients) were hepatotoxicity (8%) and diarrhea (6%).

The most common adverse reactions in patients who received TUKYSA (≥20%) were diarrhea, palmar-plantar erythrodysesthesia, nausea, hepatotoxicity, vomiting, stomatitis, decreased appetite, anemia, and rash.

Lab Abnormalities

In HER2CLIMB, Grade ≥3 laboratory abnormalities reported in ≥5% of patients who received TUKYSA were decreased phosphate, increased ALT, decreased potassium, and increased AST.

The mean increase in serum creatinine was 32% within the first 21 days of treatment with TUKYSA. The serum creatinine increases persisted throughout treatment and were reversible upon treatment completion. Consider alternative markers of renal function if persistent elevations in serum creatinine are observed.

Drug Interactions

  • Strong CYP3A/Moderate CYP2C8 Inducers: Concomitant use may decrease TUKYSA activity. Avoid concomitant use of TUKYSA.
  • Strong or Moderate CYP2C8 Inhibitors: Concomitant use of TUKYSA with a strong CYP2C8 inhibitor may increase the risk of TUKYSA toxicity; avoid concomitant use. Increase monitoring for TUKYSA toxicity with moderate CYP2C8 inhibitors.
  • CYP3A Substrates: Concomitant use may increase the toxicity associated with a CYP3A substrate. Avoid concomitant use of TUKYSA where minimal concentration changes may lead to serious or life-threatening toxicities. If concomitant use is unavoidable, decrease the CYP3A substrate dosage.
  • P-gp Substrates: Concomitant use may increase the toxicity associated with a P-gp substrate. Consider reducing the dosage of P-gp substrates where minimal concentration changes may lead to serious or life-threatening toxicity.

Use in Specific Populations

  • Lactation: Advise women not to breastfeed while taking TUKYSA and for 1 week after the last dose.
  • Renal Impairment: Use of TUKYSA in combination with capecitabine and trastuzumab is not recommended in patients with severe renal impairment (CLcr < 30 mL/min), because capecitabine is contraindicated in patients with severe renal impairment.
  • Hepatic Impairment: Reduce the dose of TUKYSA for patients with severe (Child-Pugh C) hepatic impairment.

REF-7648_FINAL_01/23

Indication

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.

Please see full Prescribing Information.

References
1. TUKYSA [Prescribing Information]. Bothell, WA: Seagen Inc. January 2023. 2. Curigliano G, Mueller V, Borges V, et al. Tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB): final overall survival analysis. Ann Oncol. 2022;33(3):321-329. doi:10.1016/j.annonc.2021.12.005 3. Murthy RK, Loi S, Okines A, et al. Tucatinib, trastuzumab, and capecitabine for HER2-positive metastatic breast cancer. N Engl J Med. 2020;382(7):597-609. doi:10.1056/NEJMoa1914609 4. Lin NU, Murthy RK, Abramson V, et al. Tucatinib vs placebo, both in combination with trastuzumab and capecitabine, for previously treated ERBB2 (HER2)-positive metastatic breast cancer in patients with brain metastases: updated exploratory analysis of the HER2CLIMB randomized clinical trial. JAMA Oncol. 2023;9(2):197-205. doi:10.1001/jamaoncol.2022.5610 5. Curigliano G, Mueller V, Borges V, et al. Updated results of tucatinib vs placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB). Poster presented at: American Society of Clinical Oncology Annual Meeting; June 4-8, 2021. 6. Data on file. Seagen Inc. 7. Murthy RK, Loi S, Okines A, et al. Tucatinib, trastuzumab, and capecitabine for HER2-positive metastatic breast cancer. N Engl J Med. 2020;382(7):597-609. Protocol. doi:10.1056/NEJMoa1914609 8. Lin NU, Murthy RK, Abramson V, et al. Updated results of tucatinib vs placebo added to trastuzumab and capecitabine for patients with previously treated HER2+ metastatic breast cancer with brain metastases (HER2CLIMB). Poster presented at: San Antonio Breast Cancer Symposium; December 7-10, 2021; San Antonio, TX. 9. Lin NU, Borges V, Anders C, et al. Intracranial efficacy and survival with tucatinib plus trastuzumab and capecitabine for previously treated HER2-positive breast cancer with brain metastases in the HER2CLIMB trial. J Clin Oncol. 2020;38(23):2610-2619. doi:10.1200/JCO.20.00775 10. Curigliano G, Murthy R, Loi S, et al. Tucatinib vs placebo added to trastuzumab and capecitabine in previously treated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB). Ann Oncol. 2020;31(suppl 2):S62-S63. doi:10.1016/j.annonc.2020.03.238 11. Murthy RK, Loi S, Okines A, et al. Tucatinib, trastuzumab, and capecitabine for HER2-positive metastatic breast cancer. N Engl J Med. 2020;382(7):597-609. Supplementary appendix. doi:10.1056/NEJMoa1914609 12. Eisenhauer EA, Therasse P, Bogaerts J, et al. New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1). Eur J Cancer. 2009;45(2):228-247. doi:10.1016/j.ejca.2008.10.026
 

Important Safety Information + Indication

Find Out More+

Warnings and Precautions

  • Diarrhea: TUKYSA can cause severe diarrhea including dehydration, hypotension, acute kidney injury, and death. 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.

    In HER2CLIMB, when TUKYSA was given in combination with trastuzumab and capecitabine, 81% of patients who received TUKYSA experienced diarrhea, including 0.5% with Grade 4 and 12% with Grade 3. Both patients who developed Grade 4 diarrhea subsequently died, with diarrhea as a contributor to death. Median time to onset of the first episode of diarrhea was 12 days and the median time to resolution was 8 days. Diarrhea led to TUKYSA dose reductions in 6% of patients and TUKYSA discontinuation in 1% of patients. Prophylactic use of antidiarrheal treatment was not required on HER2CLIMB.