Significant Palliative Benefits Following Therapy With Mifepristone for Advanced Treatment Resistant Small Cell Lung...

Area of Science:

• Oncology
• Pharmacology

Background:

• Progesterone receptor antagonists (PRAs) offer palliative benefits in advanced cancers, targeting membrane progesterone receptors (mPRs) to inhibit progesterone induced blocking factor (PIBF).
• Classical nuclear progesterone receptors (nPRs) are often absent in cancers responsive to PRAs.

Observation:

• A patient with stage IV EGFR-mutated non-small cell lung cancer (NSCLC) progressed after osimertinib treatment.
• A subsequent biopsy confirmed small cell lung cancer (SCLC), which was refractory to immunotherapy (pembrolizumab, atezolizumab).

Findings:

• Treatment with the single oral agent mifepristone resulted in significant clinical and radiographic improvement in the SCLC patient.
• Despite initial success, the patient's tumor eventually progressed, leading to a switch in therapy and subsequent clinical deterioration.

Implications:

• This case report suggests that SCLC, often resistant to conventional treatments, may respond to PR antagonists.
• Mifepristone demonstrates potential as a therapeutic option for treatment-resistant SCLC, warranting further investigation.