Abstract 1652P
Background
In 2019 Atezolizumab (Atezo) was approved for extended disease small cell lung cancer (ED-SCLC) in combination with cytotoxic chemotherapy by the European Medicines Agency. In the clinical trial IMpower133 only 22 out of 201 patients received prophylactic cranial radiotherapy (PCI) during their treatment with Atezo. No other clinical studies have reported efficacy or safety regarding the combination of radiotherapy (PCI, whole brain radiotherapy (WBR) or consolidating thoracic radiotherapy (TRTX)) with Atezo as single agent or in combination with chemotherapy. In the clinical routine these safety data are urgently needed for treatment decisions of (radio)-oncologists.
Methods
We performed a retrospective data analysis of all patients with SCLC who were treated at the Department of Medical Oncology, Evang. Kliniken Essen-Mitte from January 2019 until April 2021. Patients with combined chemo-/immunotherapy as induction treatment or with immunotherapy as maintenance were compared to those without any immunotherapy receiving similar radiotherapies. If possible pulmonary function before and after pulmonary irradiation was tested. Odds-Ratio for any documented adverse event (AE) and progression-free survival (PFS) for the different groups were calculated.
Results
35 SCLC patients underwent cranial and/or thoracal irradiation (17 patients received both treatments yet). Atezo was administered to 11 of them. 18 Patients received combined chemo-/immunotherapy without any radiotherapy. There were no severe AEs in patients with PCI or WBR regardless of simultaneous administration of Atezo. In patients with TRTX, there was no significant difference in grade I to III AEs. Grade IV AE did only appear in patients without Atezo. A trend towards an improved median PFS was found in patients with TRTX (8.8 months vs. 6.0 months, p=0.062). In five patients, who received TRTX during Atezo maintenance there is preliminary evidence for no deterioration of pulmonary function compared to patients with TRTX without Atezo.
Conclusions
The addition of simultaneous radiotherapy to Atezo-based systemic therapy seems not to be associated with increased toxicity in SCLC patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
D.C. Christoph: Financial Interests, Invited Speaker: AstraZeneca; Financial Interests, Invited Speaker: Bayer; Financial Interests, Invited Speaker: Boehringer Ingelheim; Financial Interests, Invited Speaker: Bristol Myers Squibb; Financial Interests, Invited Speaker: Chugai; Financial Interests, Invited Speaker: MSD; Financial Interests, Invited Speaker: Merck Sharp & Dohme; Financial Interests, Invited Speaker: Novartis; Financial Interests, Invited Speaker: Pfizer; Financial Interests, Invited Speaker: Roche; Financial Interests, Invited Speaker: Sanofi; Financial Interests, Invited Speaker: Takeda; Financial Interests, Writing Engagements: AstraZeneca; Financial Interests, Expert Testimony: AstraZeneca; Financial Interests, Expert Testimony: Bayer; Financial Interests, Expert Testimony: Boehringer Ingelheim; Financial Interests, Expert Testimony: Bristol Myers Squibb; Financial Interests, Expert Testimony: Chugai; Financial Interests, Expert Testimony: MSD; Financial Interests, Expert Testimony: Merck Sharp & Dohme; Financial Interests, Expert Testimony: Novartis; Financial Interests, Expert Testimony: Pfizer; Financial Interests, Expert Testimony: Roche; Financial Interests, Expert Testimony: Sanofi; Financial Interests, Expert Testimony: Takeda; Financial Interests, Speaker’s Bureau: AstraZeneca; Financial Interests, Speaker’s Bureau: Bayer; Financial Interests, Speaker’s Bureau: Boehringer Ingelheim; Financial Interests, Speaker’s Bureau: Bristol Myers Squibb; Financial Interests, Speaker’s Bureau: Chugai; Financial Interests, Speaker’s Bureau: MSD; Financial Interests, Speaker’s Bureau: Merck Sharp & Dohme; Financial Interests, Speaker’s Bureau: Novartis; Financial Interests, Speaker’s Bureau: Pfizer; Financial Interests, Speaker’s Bureau: Roche; Financial Interests, Speaker’s Bureau: Sanofi; Financial Interests, Speaker’s Bureau: Takeda; Financial Interests, Advisory Board: AstraZeneca; Financial Interests, Advisory Board: Bayer; Financial Interests, Advisory Board: Boehringer Ingelheim; Financial Interests, Advisory Board: Bristol Myers Squibb; Financial Interests, Advisory Board: Chugai; Financial Interests, Advisory Board: MSD; Financial Interests, Advisory Board: Merck Sharp & Dohme; Financial Interests, Advisory Board: Novartis; Financial Interests, Advisory Board: Pfizer; Financial Interests, Advisory Board: Roche; Financial Interests, Advisory Board: Sanofi; Financial Interests, Advisory Board: Takeda; Non-Financial Interests, Principal Investigator: AstraZeneca; Non-Financial Interests, Principal Investigator: Bristol Myers Squibb; Non-Financial Interests, Principal Investigator: MSD; Non-Financial Interests, Principal Investigator: Merck Sharp & Dohme; Non-Financial Interests, Principal Investigator: Roche; Non-Financial Interests, Member: ASCO; Non-Financial Interests, Member: DGHO; Non-Financial Interests, Member: ESMO; Non-Financial Interests, Member: IASLC. All other authors have declared no conflicts of interest.