Method of improving prediction of response for cancer patients treated with immunotherapy
A method of determining a therapeutic regimen in a patient with cancer comprising determining in a sample from the patient the tumor mutation burden (TMB) and loss of heterozygosity (LOH), wherein high TMB in combination with no LOH is indicative of a positive outcome when treated with a checkpoint inhibitor and high TMB with LOH is indicative of a poor outcome, is provided herein.
1 . A method comprising:
(a) determining a tumor mutation burden (TMB) score as high for coding exons of nucleic acid in a tumor sample obtained from a human cancer patient, wherein the determining the TMB score as high comprises:
determining a number of mutations per megabase (Mb) using a genomic profiling assay that targets >500 genes including a major histocompatibility complex (MHC) class I gene and does not target a whole human exome, and
estimating a number of mutations per exome based on the number of mutations per Mb,
wherein the TMB score is determined to be a high TMB score when there are greater than 120 mutations per exome, and wherein the genomic profiling assay uses hybrid capture to capture the MHC class I gene;
(b) detecting, using the genomic profiling assay, a presence of a loss of heterozygosity (LOH) status near or at the MHC class I gene locus in the nucleic acid from the tumor sample;
(c) predicting the human cancer patient as not a likely responder to an administration with a checkpoint inhibitor; and
(d) administering a treatment regimen other than the checkpoint inhibitor to the human cancer patient, wherein the treatment regimen comprises an activation immunotherapy that is not a checkpoint inhibitor, a suppression immunotherapy, a chimeric antigen receptor (CAR) T-cell therapy, a tumor-infiltrating lymphocyte (TIL) therapy, a T-cell receptor (TCR) therapy, a chemotherapy, a radioactive therapy, or a cancer vaccine.
2 . The method of claim 1 , wherein the cancer is selected from breast, pancreatic, lung, melanoma, hematopoietic cancers and leukemias, colon, kidney, head and neck, brain, bone, ovarian, cervical, endometrial and prostate cancer.
3 . The method of claim 1 , wherein the checkpoint inhibitor is pembrolizumab, nivolumab, atezolizumab, avelumab, durvalumab, or ipilimumab.
4 . The method of claim 1 , wherein the genomic profiling assay targets 507 genes.
5 . The method of claim 1 , wherein the mutations comprise a neoantigen or neoepitope recognized by a T cell.
6 . The method of claim 5 , wherein the neoantigen includes a neoantigen presenting complex locus comprising regions near or including a B2M gene.
7 . The method of claim 1 , wherein the MHC class I gene comprises one or more human leukocyte antigen (HLA) genes selected from the group consisting of HLA-F, HLA-V, HLA-P, HLA-G, HLA-H, HLA-T, HLA-K, HLA-U, HLA-A, HLA-W, HLA-J, HLA-L, HLA-N, HLA-E, HLA-C, HLA-B, HLA-S, HLA-DRA, HLA-DRB9, HLA-DRB5, HLA-DRB6, HLA-DRB1, HLA-DQA1, HLA-DQB1, HLA-DQB1-AS1, HLA-DQB3, HLA-DQA2, HLA-DQB2, HLA-DOB, HLA-Z, HLA-DMB, HLA-DMA, HLA-DOA, HLA-DPA1, HLA-DPB1, HLA-DPA2, HLA-DPB2 and HLA-DPA3.
8 . The method of claim 1 , wherein the detecting the presence of the LOH status comprises detecting an allelic imbalance in the nucleic acid.
9 . The method of claim 8 , wherein the detecting the allelic imbalance comprises detecting an uneven number of copies of the MHC class I gene locus.
10 . The method of claim 9 , wherein the detecting the uneven number of copies of the MHC class I gene locus comprises detecting somatic amplification, somatic deletion, contiguous homozygosity, and/or complete allelic loss.
11 . The method of claim 1 , wherein the TMB score and the LOH status are determined from a same next generation sequencing (NGS) assay.
12 . The method of claim 1 , wherein the genes targeted by the genomic profiling assay comprise oncogenes, tumor suppressor genes, genes encoding tumor antigens produced by oncogenic viruses, genes encoding cell surface glycolipids and glycoproteins and/or genes encoding oncofetal antigens.
13 . The method of claim 1 , wherein the number of mutations per exome is estimated using extrapolation based on a correlation between the number of mutations per Mb and the number of mutations per exome.
14 . The method of claim 1 , wherein the presence of the LOH status is detected near or at the MHC class I gene locus and at a B2M gene locus in the nucleic acid from the tumor sample.
15 . The method of claim 1 , wherein the treatment regimen is the chemotherapy.
16 . The method of claim 1 , wherein the treatment regimen is the CAR T-cell therapy.
17 . The method of claim 1 , wherein the treatment regimen is the activation immunotherapy that is not a checkpoint inhibitor.
18 . The method of claim 1 , wherein the treatment regimen is the suppression immunotherapy.
19 . The method of claim 1 , wherein the treatment regimen is the TIL therapy.
20 . The method of claim 1 , wherein the treatment regimen is the TCR therapy.
21 . The method of claim 1 , wherein the treatment regimen is the radioactive therapy.
22 . The method of claim 1 , wherein the treatment regimen is the cancer vaccine.