Osimertinib 80 mg EOD? Does this work?

Abstract

Osimertinib is a third-generation thyroxine kinase inhibitor (TKI) used in treating advanced non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation. Osimertinib is used as a second line treatment for patients who develop EGFR T790 M resistance mutation rather than first line due to financial constraints. We present a case of a 60-year-old Chinese gentleman who diagnosed as stage 4 adenocarcinoma with EGFR Exon 19 deletion. His disease progressed after a year of treatment with afatinib. His plasma T790 M was negative and due to delay in tissue biopsy, he was empirically started on osimertinib. However, in view of financial concerns, he opted a dose reduction of 80 mg every alternate day rather than the conventional dose of 80 mg daily. Serial CT Thorax showed partial response based on RECIST 1.1 criteria and he has 9 months of progression free survival. This case report shows that Osimertinib in reduced dose may achieve good partial response and progression free survival in patients.

Challenges and Strategies for Improving Access to Cancer Drugs in Malaysia: Summary of Opinions Expressed at the 2nd MACR International Scientific Conference 2022

“…To this end, some oncologists may opt for off-label practices, such as changing the frequency of taking long half-life drugs from daily to every other day. 45 Lowering the dose of the cancer drug is also a strategy to reduce the cost of cancer treatment. For osimertinib, a third-generation tyrosine kinase inhibitor used to treat metastatic non-small cell lung cancer patients with specific epidermal growth factor receptor ( EGFR ) mutations, for example, results of the AURA1 clinical trial showed that the response rates among patients with detectable EGFR mutation T790M was similar across all dose levels (20 mg, 40 mg, 80 mg, 160 mg, and 240 mg).…”

“… 46 Preliminary results from a small group of 29 patients in an ongoing clinical trial also showed that prescribing half the dose (40 mg instead of the conventional 80 mg) resulted in an acceptable response rate and median progression-free survival in the patients. 45 Thus, if positive results are obtained in future larger-scale trials, the cost of treatment with osimertinib may be reduced to half.…”

“…resulted in an acceptable response rate and median progression-free survival in the patients. 45 Thus, if positive results are obtained in future larger-scale trials, the cost of treatment with osimertinib may be reduced to half.…”

Reduced frequency dosing of osimertinib in EGFR-mutant non-small cell lung carcinoma: real world data

“…A case report described a Chinese gentleman with metastatic lung adenocarcinoma with EGFR exon 19 deletion whose disease had progressed on afatinib, and whose blood EGFR T790M was negative. He received osimertinib 80 mg orally every other day, with a good partial response (PR) and a PFS of 9 months [ 20 ]. Based on the encouraging preclinical and early clinical data, we administered osimertinib 80 mg orally at a reduced frequency on a compassionate basis to patients with EGFR mutant lung cancer who were unable to afford full dose osimertinib, refused or had progressed on intravenous chemotherapy and did not have any other treatment options available.…”

Reduced frequency dosing of osimertinib in EGFR-mutant non-small cell lung carcinoma: Real world data

“…A case report described a Chinese gentleman with metastatic lung adenocarcinoma with EGFR exon 19 deletion whose disease had progressed on afatinib, and whose blood EGFR T790M was negative. He received osimertinib 80 mg orally every other day, with a good partial response and a PFS of 9 months [29]. Based on the encouraging preclinical and early clinical data, we administered osimertinib 80 mg orally at a reduced frequency on a compassionate basis in patients with EGFR mutant lung cancer who were unable to afford full dose osimertinib, refused or had progressed on intravenous chemotherapy, and did not have any other treatment options available.…”