Phase I study of single-agent anti-programmed death-1 (MDX-1106) in refractory solid tumors: safety, clinical activity, pharmacodynamics, and immunologic correlates.
OBJECTIVE
Programmed death-1 (PD-1), an inhibitory receptor expressed on activated T cells, may suppress antitumor immunity. This phase I study sought to determine the safety and tolerability of anti-PD-1 blockade in patients with treatment-refractory solid tumors and to preliminarily assess antitumor activity, pharmacodynamics, and immunologic correlates.


METHODS
Thirty-nine patients with advanced metastatic melanoma, colorectal cancer (CRC), castrate-resistant prostate cancer, non-small-cell lung cancer (NSCLC), or renal cell carcinoma (RCC) received a single intravenous infusion of anti-PD-1 (MDX-1106) in dose-escalating six-patient cohorts at 0.3, 1, 3, or 10 mg/kg, followed by a 15-patient expansion cohort at 10 mg/kg. Patients with evidence of clinical benefit at 3 months were eligible for repeated therapy.


RESULTS
Anti-PD-1 was well tolerated: one serious adverse event, inflammatory colitis, was observed in a patient with melanoma who received five doses at 1 mg/kg. One durable complete response (CRC) and two partial responses (PRs; melanoma, RCC) were seen. Two additional patients (melanoma, NSCLC) had significant lesional tumor regressions not meeting PR criteria. The serum half-life of anti-PD-1 was 12 to 20 days. However, pharmacodynamics indicated a sustained mean occupancy of > 70% of PD-1 molecules on circulating T cells > or = 2 months following infusion, regardless of dose. In nine patients examined, tumor cell surface B7-H1 expression appeared to correlate with the likelihood of response to treatment.


CONCLUSIONS
Blocking the PD-1 immune checkpoint with intermittent antibody dosing is well tolerated and associated with evidence of antitumor activity. Exploration of alternative dosing regimens and combinatorial therapies with vaccines, targeted therapies, and/or other checkpoint inhibitors is warranted.
Johns Hopkins University School of Medicine, and the Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD, USA.
Julie R
JR
Brahmer
Charles G
CG
Drake
Ira
I
Wollner
John D
JD
Powderly
Joel
J
Picus
William H
WH
Sharfman
Elizabeth
E
Stankevich
Alice
A
Pons
Theresa M
TM
Salay
Tracee L
TL
McMiller
Marta M
MM
Gilson
Changyu
C
Wang
Mark
M
Selby
Janis M
JM
Taube
Robert
R
Anders
Lieping
L
Chen
Alan J
AJ
Korman
Drew M
DM
Pardoll
Israel
I
Lowy
Suzanne L
SL
Topalian
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D015703:Antigens, CD / Q000276:immunology*; D051017:Apoptosis Regulatory Proteins / Q000276:immunology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000188:drug therapy / Q000473:pathology; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005221:Fatigue / Q000139:chemically induced; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000473:pathology; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology; D008231:Lymphopenia / Q000139:chemically induced; D008297:Male; D008545:Melanoma / Q000188:drug therapy / Q000473:pathology; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D000077594:Nivolumab; D061026:Programmed Cell Death 1 Receptor; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D000077594:Nivolumab