Case Study 10

For each question, choose the answer you think is correct. Answers are provided at the end of the page.
​​​​L.A. is a 77-year-old male diagnosed with stage IV non-small cell lung cancer.  Biopsy testing demonstrates an EGFR-mutation positive adenocarcinoma with T790M mutation. His performance status is ECOG 1. He was deemed as an appropriate candidate for the LUAVOSI​ protocol.

Lab results taken 24 hours prior to first treatment:
Lab value
 Patient's labs
 Normal range 
WBC
7.3
4 – 10 x 109/L
ANC
5.1
2 – 7.5 x 109/L
Hgb
126
115 – 155 g/L
Plt
331
150 – 400 x 109/L
SCr
59
45 – 90 µmol/L
eGFR
86
≥ 60 mL/min/1.73m2
Potassium
3.8
3.5 – 5 mmol/L
Magnesium
0.83
0.64 - 0.98 mmol/L
Calcium
2.4
2.1 - 2.6 mmol/L
ALT
17
<36 U/L
ALP
96
35 – 120 U/L
Total bilirubin
4
<17 µmol/L​​
LD
410
<225 U/L
CRP
56<4.8 mg/L

Weight = 65.2 kg, Height = 165 cm
ECG done last week shows QTc interval of 449 milliseconds.

1. Which of the following are acceptable patient identifiers to confirm that the prescription you received was written for L.A.?

  1. Patient's name
  2. Patient's name and date of birth
  3. Patient's name and PHN
  4. Options 2 and 3 are correct
  5. Any of the above

2. What type of drug therapy is osimertinib classified as?

  1. Chemotherapy
  2. Targeted immunotherapy using PD-1 immune checkpoint inhibition
  3. Targeted therapy using ty​rosine kinase inhibition
  4. Targeted therapy using  CDK4/6 inhibition

3. After surgery for partial removal of his tumour, L.A. was experiencing swallowing difficulty as well as cachexia. He now has a nasogastric (NG) tube. Is he still a candidate for oral osimertinib therapy?

  1. No, as he has swallowing difficulty and osimertinib is supplied as a large tablet
  2. Yes, the tablet can be dispersed in 15 mL of non-carbonated, room temperature water and administered through the NG tube, then flushed with another 15 mL water
  3. No, as Osimertinib is a hazardous drug, it should not be crushed or dissolved
  4. Yes, Osimertinib is supplied as a small tablet, and he should be able to swallow it easily

4. What is the standard dosing regimen of osimertinib? 

  1. one 80 mg tablet PO once daily, do not eat grapefruit or drink grapefruit juice while taking this medication
  2. one 80 mg tablet PO once daily with a high-fat meal
  3. one 80 mg tablet PO once daily for 2 weeks, then 2 weeks off
  4. one 80 mg tablet PO once daily for 3 weeks, then 1 week off

5. After 3 weeks of continuous therapy, L.A. develops a mild but itchy papulopustular rash on his face and upper chest and calls for help. Which of the following would NOT be an appropriate management option?

  1. Treat the affected area with a topical steroid cream. Counsel to minimize sun exposure and to wear broad-spectrum sunscreen.
  2. Avoid using hot water to bathe or wash dishes. Counsel to minimize sun exposure and to wear broad-spectrum sunscreen. 
  3. Treat with topical acne medication. Counsel to minimize sun exposure and to wear broad-spectrum sunscreen.
  4. Moisturize skin with a thick alcohol-free emollient. Counsel to minimize sun exposure and to wear broad-spectrum sunscreen.

6. 6 months after the start of his treatment, L.A. mentions that he is experiencing blurred vision, especially at night. He wears contact lenses and seems to be experiencing more dry eyes as well. What could be the reason for his recent vision changes? 

  1. His vision changes may be exacerbated by his contact lens use; he should stop using contact lenses. 
  2. Osimertinib use can cause changes in eyes including dry eye disease and keratitis, an ophthalmologist consult should be requested.
  3. Due to his blurred vision, he should exercise caution when driving or operating machinery.
  4. All of the above 

7. Two years after the start of his treatment, L.A. reports having shortness of breath, increased tiredness, difficulty walking up the stairs and some peripheral edema. This has resulted in him being less physically active than before. His family physician recently did some blood tests and they show a high level for B-type natriuretic peptide (BNP). What other assessments should be carried out to find the cause of his symptoms?

  1. Age related changes are common; he should follow up with his family physician.
  2. As he has been less physically active, he is experiencing water retention in his legs. Consult with prescriber and recommend starting furosemide to help with his peripheral edema.
  3. He may be experiencing osimertinib related cardiomyopathy, consult with prescriber and recommend doing ECG and checking left ventricular ejection fraction via echocardiogram or MUGA scan.
  4. Consult with prescriber and recommend doing a chest X-ray to check for disease progression in lungs.
    ​

 
The correct answer is 4.

​ Rationale: According to the BC Cancer Clinical Pharmacy Guide module 2, a minimum of two patient identifiers are required to confirm patient identity. These identifiers include two of the following: name, date of birth, identification number (BC Cancer/hospital/PHN).

 
The correct answer is 3.

​ Rationale:  As mentioned in the BC Cancer drug monograph for osimertinib, it is a third generation, oral, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that inhibits the activity of HER2, HER3, HER4, ACK1, and BLK.

 
The correct answer is 2.

Rationale:  ​According to the BC Cancer Drug Manual monograph for osimertinib, the tablet can be dispersed in 15 mL non-carbonated, room temperature water​ (other liquids should not be used) for nasogastric administration, and stirred to disperse. Do not crush tablets or heat the solution to aid dispersion. Tablets will not completely dissolve. Follow with a rinse and flush with 15 mL water. 

Administration should be completed within 30 minutes of the addition of tablets to water.

 

The correct answer is 1.

Rationale:  According to the BC Cancer drug monograph for osimertinib, grapefruit juice can increase the plasma level of osimertinib and therefore, should be avoided. The BC Cancer Auxiliary Label List suggests adding the “Do not eat grapefruit or drink grapefruit juice while taking this medication” label on the vial. Standard dosing is 80 mg orally once daily.

 
The correct answer is 3.

Rationale:  According to the BC Cancer drug monograph for osimertinib, patients may experience pruritic papulopustular rash. Pre-emptive skin care measures such as moisturizing with a thick alcohol-free emollient, avoiding hot showers, minimizing sun exposure, and using broad-spectrum sunscreen are advised. Prophylactic treatment with topical/oral steroids and antibiotics may reduce the severity of skin reactions and help to maintain dose intensity. However, the rash is clinically and histologically distinct from acne, and therefore, should not be treated with topical acne medication.

 
The correct answer is 4.

Rationale:  According to the precautions section, 4. “Ocular disorders” sub-section of LUAVOSI protocol, and the Side Effect paragraphs section of the Cancer Drug Manual osimertinib monograph, osimertinib has been associated with keratitis, conjunctivitis, blepharitis, and dry eye. Ophthalmologic consultation should be considered for associated symptoms. Contact lens use is known to be an independent risk factor for ocular toxicity, including keratitis. Caution should be exercised when driving or operating machinery. 

 
​The correct answer is 3.

Rationale:  According to the BC Cancer drug monograph for osimertinib, cardiomyopathy has been observed, including congestive heart failure, pulmonary edema, and decreased ejection fraction in patients taking osimertinib. Patients who develop cardiac symptoms while on osimertinib require LVEF assessment. An ECG and chest X-Ray may also be useful diagnostic tests.