Neoadjuvant CPA followed by surgical resection and maintenance atezolizumab meets safety criteria

Neoadjuvant cisplatin and pemetrexed plus atezolizumab followed by surgical resection and maintenance atezolizumab met safety criteria, according to research presented today in OA13: Topics in Pleural Mesothelioma at the IASLC 2021 World Conference on Lung Cancer.

Dr. Anne Tsao of MD Anderson Cancer Center in Houston and her clinical site co-researchers randomly assigned 24 patients with epithelioid or biphasic histology whose disease wasresectable by pleurectomy/decortication (P/D) or extrapleural pneumonectomy (EPP), who underwent extended surgical staging with mediastinoscopy or endobronchial ultrasound and laparoscopy, and who did not receive prior chemo or immunotherapy.

Safety was defined as no Grade 4-5 immune-related adverse event; feasible if 18/24 (75%) received at least one dose of maintenance therapy. Patients were divided into two cohorts --the pleurectomy/decortication cohort or the extrapleural penomonectomy cohort.

Patients received four cycles of neoadjuvant cisplatin and pemetrexed plus atezolizumab (CPA), resection, then radiation (EPP cases only), followed by one year of maintenance atezolizumab.

Twenty-eight eligible patients were enrolled (Nov 2017 - May 2020); 25 received at least two cycles of neoadjuvant CPA, 18 underwent surgery, and 15 received maintenance atezolizumab. Median age was 68.1 (31.5 – 77.3), with 20 men and eight women.

There were 24 planned pleurectomies/decortications (P/D) and four planned EPPs. Twenty-one patients completed neoadjuvant therapy, but seven patients did not proceed to resection (2 toxicity, 4 disease progression, 1 death). The one treatment-related death occurred from sepsis associated with nonimmune-related renal and respiratory failure. Eighteen patients with stable disease or partial response proceeded to surgical resection; 17 received a P/D and 1 EPP. One patient did not receive protocol-specified surgery due to progressive disease. Postoperatively, one patient had a fatal cardiovascular event. Sixteen patients registered to receive maintenance atezolizumab for one year, but one patient was ineligible due to inadequate hematologic function.

To date, no treatment-related adverse events more serious than grade 3 were reported. Three patients remain ongoing with maintenance atezolizumab therapy.

Neoadjuvant cisplatin and pemetrexed plus atezolizumab followed by surgical resection and maintenance atezolizumab met safety criteria. Sixty percent of eligible patients proceeded to maintenance atezolizumab, and additional monitoring will assess efficacy and long-term toxicity outcomes."

Dr. Anne Tsao, MD Anderson Cancer Center, Houston