Abstract 1055P
Background
An ongoing, first-in-human, two-part (dose escalation, dose expansion), phase I study is assessing SC PF-06801591, a humanized IgG4 PD-1 receptor antibody, in patients (pts) with solid tumors. Results from part 2 in pts with NSCLC or UC up to Dec 2018 have been reported (ESMO 2019;1275P). Here, we provide updated safety and efficacy data to 1 Nov 2019 with longer treatment duration and follow up.
Methods
Anti-PD-1/L1 naïve pts (≥18 years) with NSCLC or UC who progressed on, were intolerant to, or were refused systemic therapy, or for whom it was unavailable, received SC PF-06801591 300mg q4w. Archival or fresh tumor tissue was used for immunohistochemistry. Tumor response was assessed q8–12w by RECIST v1.1.
Results
In 106 pts (NSCLC=68, UC=38), median treatment duration was 113.0 days (NSCLC=113.0 days, UC=102.0 days) and was ongoing in 31.8% of pts. 56.6% of pts had treatment-related adverse events (TRAEs), 13.2% at grade 3–4. The commonest TRAEs were hyperthyroidism (10.4%), pruritus (7.5%), increased lipase (6.6%), and increased alanine aminotransferase/amylase/aspartate aminotransferase, anemia, hypothyroidism, and rash (5.7% each). Median follow up duration was 213.5 and 265.5 days for NSCLC and UC pts, respectively. In the modified intent to treat (mITT) NSCLC population (n=67), 0% had a complete response (CR), 20.9% a partial response (PR, median duration 230.0 days), and 35.8% stable disease (SD, median duration 168.0 days). Objective response rate (ORR) was 20.9% (95% confidence interval [CI] 11.9–32.6%), and 32.1% and 45.5% in pts with PD-L1 tumor expression ≥1% and ≥50%, respectively. In the mITT UC population (n=38), 0% had a CR, 21.1% a PR (median duration 183.0 days), and 31.6% SD (median duration 118.5 days). ORR was 21.1% (95% CI 9.6–37.3%), and 40.0% and 50.0% in pts with PD-L1 tumor expression ≥1% and ≥50%, respectively. Survival data will be presented.
Conclusions
In this update of SC PF-06801591 300mg q4w in pts with NSCLC or UC, the longer-term safety profile was consistent with previous reports. Durable antitumor activity was demonstrated.
Clinical trial identification
NCT02573259.
Editorial acknowledgement
David Cope, PhD, of Engage Scientific Solutions, funded by Pfizer.
Legal entity responsible for the study
Pfizer.
Funding
Pfizer.
Disclosure
B.C. Chul Cho: Advisory/Consultancy, Research grant/Funding (institution): Novartis; Research grant/Funding (institution): Bayer; Advisory/Consultancy, Research grant/Funding (institution): AstraZeneca; Research grant/Funding (institution): MOGAM Institute; Research grant/Funding (institution): Dong-A ST; Research grant/Funding (institution), Licensing/Royalties: Champions Oncology; Advisory/Consultancy, Research grant/Funding (institution): Janssen; Advisory/Consultancy, Research grant/Funding (institution): Yuhan; Advisory/Consultancy, Research grant/Funding (institution): Ono; Research grant/Funding (institution): Dizal Pharma; Advisory/Consultancy, Research grant/Funding (institution): MSD; Advisory/Consultancy: Boehringer-Ingelheim; Advisory/Consultancy: Roche; Advisory/Consultancy: BMS; Advisory/Consultancy: Pfizer; Advisory/Consultancy: Eli Lilly; Advisory/Consultancy: Takeda; Shareholder/Stockholder/Stock options: TheraCanVac Inc; Shareholder/Stockholder/Stock options: Gencurix Inc; Shareholder/Stockholder/Stock options: Bridgebio Therapeutics. K.D. Penkov: Research grant/Funding (institution): AbbVie; Research grant/Funding (institution): AstraZeneca; Research grant/Funding (institution): MSD; Research grant/Funding (institution): Pfizer; Research grant/Funding (institution): Prestige Biopharma; Research grant/Funding (institution): Regeneron; Research grant/Funding (institution): Tanvex. H.K. Ahn: Honoraria (self), Advisory/Consultancy: AstraZeneca; Honoraria (self), Advisory/Consultancy: Boehringer Ingelheim; Honoraria (self), Advisory/Consultancy: Eisai; Honoraria (self), Advisory/Consultancy: Ono; Honoraria (self), Advisory/Consultancy: Roche. R. Li, I.A. Jacobs, M. Bowers, M. Li: Pfizer. M. Johnson: Research grant/Funding (institution): BerGenBio; Research grant/Funding (institution): Lilly; Research grant/Funding (institution): EMD Serono; Research grant/Funding (institution): Janssen; Honoraria (institution), Research grant/Funding (institution): Mirati Therapeutics; Research grant/Funding (institution): Genmab; Research grant/Funding (institution): Pfizer; Honoraria (institution), Research grant/Funding (institution): AstraZeneca; Honoraria (institution), Research grant/Funding (institution): Genentech/Roche; Research grant/Funding (institution): Stemcentrix; Research grant/Funding (institution): Novartis; Research grant/Funding (institution): Checkpoint Therapeutics; Research grant/Funding (institution): Array BioPharma; Research grant/Funding (institution): Regeneron; Research grant/Funding (institution): Apexigen; Research grant/Funding (institution): AbbVie; Research grant/Funding (institution): Tarveda; Research grant/Funding (institution): Adaptimmune; Research grant/Funding (institution): Syndax; Research grant/Funding (institution): Neovia; Honoraria (institution), Research grant/Funding (institution): Boehringer Ingelheim; Honoraria (institution), Research grant/Funding (institution): Sanofi; Research grant/Funding (institution): Hengrui Therapeutics; Research grant/Funding (institution): INC; Honoraria (institution), Research grant/Funding (institution): Merck; Research grant/Funding (institution): Daiichi-Sankyo; Research grant/Funding (institution): Lycera; Research grant/Funding (institution): G1 Therapeutics; Research grant/Funding (institution): Dynavax; Honoraria (institution), Research grant/Funding (institution): Loxo. All other authors have declared no conflicts of interest.