The Sentinel

THE OFFICIAL BLOG OF THE SOCIETY FOR IMMUNOTHERAPY OF CANCER (SITC).

Saturday, November 13, 2021

SITC AMPCP 2021 Scientific Highlights – Saturday 11/13/21

 Off-the-shelf CAR NK cells potently control multiple tumor types

(117) FT536 Path to IND: Ubiquitous targeting of solid tumors with an off-the-shelf, first-of-kind MICA/B-specific CAR-ink cellular immunotherapy

Bryan Hancock, PhD (Fate Therapeutics) previewed the preclinical studies supporting the investigational new drug application for FT536, a CAR NK cell product derived from an inducible pluripotent stem-cell line engineered for enhanced effector cell functionality, persistence, and multi-antigen targeting capabilities through CD16-mediated antibody dependent cellular cytotoxicity (ADCC). FT536 carries a CAR targeting the pan-tumor associated antigens MICA and MICB (MICA/B) and the product can be consistently and uniformly produced as well as cryopreserved at clinical scale. Potent and persistent antigen-specific cytotoxicty was demonstrated against an array of solid and hematological tumor lines. Activity of FT536 was further augmented when combined with chemotherapies and/or radiation that induced surface MICA/B expression. Multi-targeting through the CAR and CD16-mediated ADCC was also demonstrated when FT536 was combined with trastuzumab or cetuximab for HER2- or EGFR-expressing tumors, respectively. In xenograft models, directly thawed frozen FT536 significantly slowed tumor growth, which was further enhanced when infused in combination with the monoclonal antibodies. Sustained persistence of FT536 for 33 days post-infusion were also seen in a murine model of lung adenocarcinoma. These preclinical findings support further development of FT536 as a universal adoptive cell therapy.

 

 

Anti-CD47 shrinks breast cancer brain metastases

(270) Anti-CD47 immunotherapy as a therapeutic strategy for the treatment of breast cancer brain metastasis

Jessica D. Mackert, PhD (Wake Forest University) described preclinical data supporting CD47 as a target for the treatment of brain metastases in triple-negative breast cancer (TNBC). The “don’t eat me signal” CD47 is a pleitropic surface marker expressed on numerous cell types that inhibits myeloid cell phagocytic activity through binding SIRPalpha as well as an antagonizes T cell function mediated by interaction with matricellular protein Thrombospondin-1. Patient biopsies revealed an 89% increase in CD47 expression by immunohistochemistry in metastatic brain TNBC tumors compared to primary lesions. In mice bearing brain metastatic 4T1br3 tumors, anti-CD47 treatment shrank tumors by roughly 50% compared to controls, which accompanied by a 5-fold increase in expression of F4/80 macrophage markers in the tumors. A total of 318 differentially expressed genes were associated with anti-CD47 treatment, with enrichment for reduced signatures of extracellular matrix remodeling and upregluation of pathways involved in tertiary lymphoid structure formation. Knockout of CD47 led to 60% increased survival and 89% decreased metastatic brain lesions in 4T1-bearing mice compared to controls. This preclinical data supports CD47 as a potential target for the immunotherapeutic treatment of brain metastases.

 

 

DNA vaccine plus pembrolizumab for metastatic prostate cancer

(350) Phase II trial of a DNA vaccine with pembrolizumab in patients with metastatic, castration-resistant prostate cancer (mCRPC)

Douglas G. McNeel, MD, PhD (Carbone Cancer Center, University of Wisconsin) presented the final analyses from Arms 3 and 4 of a phase I/II study evaluating the pTVG-HP prostatic acid phosphatase (PAP) DNA vaccine in combination with pembrolizumab for metastatic castrate-resistant prostate cancer (mCRPC). In arm 3, the PAP DNA vaccine was given every 3 weeks (with pembrolizumab every 3 weeks) and in Arm 2, the vaccine was given every 2 weeks (with pembrolizumab every 4 weeks). The median time to progression (TTP) at the time of abstract preparation was 5.3 months for Arm 3 and 8.0 months for Arm 4. Updated 6-month disease control rates presented at the meeting were 10% and 45% of patients in Arms 3 and 4, respectively. Treatment-related adverse events ≥ grade 2 occurred at a rate of 42% across arms, and development of an immune-related adverse event was associated with prolonged TTP. Persistent increases in serum levels of interferon gamma and granzyme B were observed in both Arms (6/20 patients in Arm 4 and 2/20 patients in Arm B). These data suggest that the generation of tumor-antigen-specific T cells through vaccination may help overcome primary resistance to anti-PD-1 monotherapy in prostate cancer.   

 

 

Ibrutinib enhances CLL CAR-T cell therapy 

(449) Concurrent ibrutinib enhances T cell function in patients with chronic lymphocytic leukemia (CLL) treated with lisocabtagene maraleucel (liso-cel), a chimeric antigen receptor (CAR) T cell therapy

Jerill Thorpe, MS (Bristol Myers Squibb) described translational data supporting potential synergy between Bruton tyrosine kinase inhibitors (BTKi) and CAR T cell therapy in patients with chronic lymphocytic leukemia (CLL). Using a novel low-input RNA-seq method, CAR-positive and endogenous T cells were isolated from the patients treated in the TRANSCEND CLL 004 study, which evaluated the CD19-directed CAR T cell product lisocabtagene maraleucel (liso-cel) given with the BTKi ibrutinib (n = 19) or as monotherapy (n = 16). At 1 and 2 months post-liso-cel infusion, both populations of cells in the combination ibrutinib plus liso-cel group demonstrated positive enrichment for expression of cell proliferation genes and negative enrichment for expression of inflammation-associated genes compared to what was seen with monotherapy, though the extent was lesser in the endogenous lymphocytes. Increased CAR+ T cell expansion, reduced serum IL-6, and increased and sustained CLL ibrutinib gene expression score—which has previously been correlated with higher rates of undetectable minimal residual disease and longer progression-free survival—was also seen in the combination group. The expression of T cell exhaustion genes was reduced in CAR-positive cells from the combination group, which was associated with improved progression-free survival. These findings suggest that the addition of ibrutinib to CAR T cell therapy for CLL.  

 

 

TIL therapy plus pembrolizumab leads to durable responses

(492) Phase 2 efficacy and safety of autologous tumor-infiltrating lymphocyte (TIL) cell therapy in combination with pembrolizumab in immune checkpoint inhibitor-naïve patients with advanced cancers

David O’Malley, MD (Ohio State University) reported early efficacy and safety results from two ongoing multicenter phase II clinical trials investigating autologous tumor-infiltrating lymphocyte (TIL) therapy combined with pembrolizumab for the treatment of head and neck squamous cell carcinoma (HNSCC), melanoma, and cervical cancer. Patients’ tumors were first resected for TIL isolation and manufacturing, followed by one dose of pembrolizumab, lymphodepletion, TIL infusion intravenous IL-2, and then continued pembrolizumab for ≤ 24 months. All enrolled patients had high tumor burdens. At median follow-up of 9.7 months, the objective response rates in the full analysis set presented at the meeting were 60%, 39%, and 57%, for patients with melanoma, HNSCC, and cervical cancer, respectively. Almost all efficacy-evaluable patients achieved a reduction in tumor burden. Ongoing durable responses at data cutoff were observed in 10 of 17 patients with objective tumor response. Reporting tolerable safety results thus far, the authors advocate for further investigation of this combination immunotherapy strategy as an early line of therapy option for patients with advanced solid tumors.

 

Intact lymph nodes are essential for checkpoint inhibitor efficacy

(601) Sequencing Immunotherapy before Lymphatic Ablation Unleashes cdc1-Dependent Antitumor Immunity in HNSCC

Robert Saddawi-Konefka, MD, PhD (UC San Diego) presented preclinical evidence to determine the best sequence of therapies for head and neck squamous cell carcinoma (HNSCC) based on spatially distinct patterns of immune responses in cervical lymphatic basins. In murine models of neck dissection (ND) to remove orthotopic tobacco-signature HNSCC tumors, enrichment for conventional type I dendritic cells (cDC1)and type I interferon signaling was observed within the resected lymphatics. After ND, the tumor microenvironment was observed to be largely immunosuppressed, suggesting a loss of effector function after curative-intent surgery. Specifically, ND resulted in loss of tumor-specific CD8+ T cells and increases in myeloid suppressive cells. Supporting this, poor immune responses were observed with immune checkpoint inhibitors (ICIs) following cervical lymphatic ablation. ICIs given neoadjuvantly, however, resulted in a systemic distribution of memory anti-tumor T cells, lymph node accumulation of cDC1, and complete responses in tumors. Interestingly, administration of ICIs prior to surgery was also associated with reduced occurrence of occult nodal metastases at late time points (1 week after the last ICI dose), but not when surgery was performed at an early time point (1 day after the last ICI dose) providing preclinical evidence for the importance of the draining lymph node in generation and maintenance of prolonged anti-tumor responses.

 

 

Safety data support COVID-19 vaccination for checkpoint inhibitor-treated patients

(625) COVID-19 vaccination in patients with renal cancer or melanoma receiving immune checkpoint inhibitors

Hannah E. Dzimitrowicz, MD (Duke University) described no increased incidence of immune-related adverse events nor severe side effects associated with COVID-19 vaccination for patients receiving checkpoint inhibitors—a population that was excluded from the registration trials leading to Food and Drug Administration (FDA) approval. Retrospective data on balanced cohorts of patients with renal cell carcinoma and melanoma undergoing checkpoint blockade therapy who received one dose of an FDA-approved vaccine was presented. Half of the patients were being treated with anti-PD-1 monotherapy at the time of vaccination. Among the 40% of patients being treated with immunotherapy combinations, 10% of patients were receiving anti-PD-1 plus anti-CTLA-4 and 28% had a regimen that included anti-PD-1 plus a tyrosine kinase inhibitor. Higher rates of symptoms secondary to vaccination were reported by the ICI-treated patients, including fever, chills, arm pain, myalgias, lymphadenopathy, headache, and diarrhea, likely related to more frequent follow-up compared to the control group. The rates of new or worsening immune-related adverse events after vaccination was no higher than predicted by expected historical ICI-associated toxicity incidence rates. Only 12% of patients required a hold of checkpoint inhibitor therapy, steroids, or hospitalization due to immune-related toxicity. Some patients did develop COVID-19 after partial vaccination. Further studies with larger cohorts of patients are needed to assess efficacy of the approved COVID-19 vaccines in ICI-treated patients, yet these data indicate vaccination is safe for this vulnerable population.

 

STING agonism alters stroma to turn cold tumors hot

(758) High-potency synthetic STING agonists rewire the myeloid stroma in the tumour microenvironment to amplify immune checkpoint blockade efficacy in refractory pancreatic ductal adenocarcinoma

Akash R. Boda, MS (University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences) provided the first detailed mechanistic characterization of how synthetic agonists of the Stimulator of Interferon Genes (STING) adaptor protein perturb the myeloid stroma toward proinflammatory phenotypes. Multi-omics profiling on M2 macrophages and myeloid-derived suppressor cells of both human and murine origin revealed that exposure to synthetic cyclic dinucleotides (high-potency agonists of STING) rewired these cell populations via inhibition of c-Myc signaling, alteration of energy metabolism away from fatty acid oxidation in favor of oxidative phosphorylation, and antagonism of proliferation. In orthotopic mouse models of KRAS-driven pancreatic ductal adenocarcinoma (PDAC)an immunologically cold tumor—intratumoral injection of synthetic cyclic dinucleotides concomitant with checkpoint blockade led to enhanced T and NK cell infiltration along with improved disease control. Multiparametric flow cytometry analysis of tumors from mice treated with the combination of STING agonists and checkpoint inhibitors confirmed that remodeling of the myeloid stroma toward proinflammatory phenotypes with accompanying enhancements in T cell function were both associated with therapeutic benefit. The study not only offers new insight into the mechanisms by which cyclic dinucleotides act as immune adjuvants for anti-tumor responses, but also highlight the potential of these compounds to reverse primary resistance to checkpoint blockade in immunologically cold tumors such as PDAC.

 

 

Skin toxicity predicts improved survival with checkpoint blockade

(814) Cutaneous Immune-related Adverse Events are Protective of Mortality in Patients Treated with anti-PD1 and anti-PDL1 therapy in a multi-institutional cohort study

Yevgeniy Semenov, MD (Massachusetts General Hospital/Harvard Medical School) presented a retrospective study that included 7,008 patients who developed cutaneous immune-related adverse events (cirAEs) within 6 months of treatment initiation of anti-PD-(L)1 therapy as well as 7,008 control-matched patients that did not experience skin toxicity. Landmark analyses at 6 months showed statistically significant improvement in overall survival among the patients who developed any cirAE as well as individual toxicities including nonspecific rashes, pruritus, drug eruption, and xerosis. Other cirAE morphologies also demonstrated a trend toward improved survival without reaching statistical significance. The onset of a cirAE within 3 months or 9 months of first dose of PD-(L)1 inhibitor was similarly associated with a reduced risk of death (HR 0.759, p < 0.0001 for a 3 month landmark time; HR 0.84, p < 0.0001 for a 9 months landmark time). These data suggest that many dermatologic irAEs may be predictive of survival benefit from anti-PD(L)1 therapy.  

 

 

Combination pembrolizumab plus oncolytic virus improves CR rates for NMIBC

(955) CORE1: Phase 2, Single Arm Study of CG0070 Combined with Pembrolizumab in Patients with Non Muscle Invasive Bladder Cancer (NMIBC) Unresponsive to Bacillus Calmette-Guerin (BCG)

Roger Li, MD (Moffitt Cancer Center) reported early data from a phase II study of an intravesical oncolytic virus combined with systemic pembrolizumab therapy for the treatment of BCG-unresponsive non-muscle-invasive bladder cancer (NMIBC). CG0070 is a GM-CSF-expressing adenovirus engineered to harbor the transcription factor E2F, which allows for preferential replication in tumor cells with defects in the tumor suppressor protein retinoblastoma—resulting in lysis and immunogenic cell death. Encouraging CR rates have been reported previously in separate studies of CG0070 and pembrolizumab monotherapies for NMIBC, and this is the first trial assessing a combination approach. The primary study endpoint is CR at 12 months, with secondary endpoints of CR at any time, progression-free survival, duration of response, cystectomy-free survival, and safety. At the time of abstract submission, 5 out of 5 assessed patients had achieved CR at 3 months, and there were no grade ≥ 3 adverse events reported. Updated data presented at the meeting confirmed the 100% CR rate at 3 months in 2 additional patients and demonstrated ongoing CRs at 6 and 9 months for the 2 and 6 patients for whom longer follow-up was available. These preliminary data support further evaluation of CG0070 plus pembrolizumab, a combination that has demonstrated unprecedented CR rates, has been well-tolerated to date and may exhibit synergistic anti-tumor effects.

 

 

SITC AMPCP 2021 Scientific Highlights – Friday 11/12/21

Engineered myeloid cells make the microenvironment more favorable 

209 Genetically Engineered Myeloid Cells (GEMys) as a Platform to Enhance Antitumor Immunity 

Sabina Kaczanowska, PhD (National Cancer Institute) presented evidence that engineered IL-12-expressing myeloid cells home to tumors and modulate effector cell functions in the microenvironment. Previous work by this group has demonstrated that bone marrow-derived myeloid cells play a central role in establishing the pre-metastatic niche. In murine models of lung metastases, treatment with IL-12-expressing myeloid cells was associated with robust interferon gamma responses, elevated antigen presentation machinery, and high infiltrating T and NK cells expressing effector markers. Tumor growth was blunted in mice infused with engineered cells, resulting in fewer metastases, and prolonged survival compared to controls. When combined with chemotherapy pre-conditioning, treatment not only was associated with complete rejection of established tumors but also resistance to rechallenge. Translation of these findings into human patients could open the door for myeloid-targeting strategies to prevent metastasis in advanced cancer.

 

Combination improves survival for immunologically cold endometrial cancer 

(354) Lenvatinib and pembrolizumab in advanced endometrial carcinoma (EC): long-term efficacy and safety update from a phase 1b/2 study

Vicky Makker, MD (Memorial-Sloan Kettering Cancer Center) delivered an update from a phase Ib/II study of the multikinase inhibitor lenvatinib plus the pembrolizumab for metastatic, pre-treated endometrial carcinoma. The trial enrolled  108 patients, 94 of whom had confirmed microsatellite stable (MSS)/mismatch repair proficient (pMMR) disease and 11 with documented microsatellite instability high (MSI-H)/mismatch repair deficient (dMMR) tumors. At data cutoff on January 10, 2019 with a median follow-up of 18.7 months, the objective response rate (ORR) was 38.9%, median progression-free survival (PFS) was 7.4 months, and median overall survival (OS) was 16.7 months. Now, with a median follow up of 34.7 months, the updated ORR is 38.3% (including an 8.3% complete response rate) and 63.6% for MSHI-H/dMMR tumors. Median PFS remained consistent with the first analysis at 7.4 months (7.4 and 26.4 months for MSS/pMMR and MSI-H/dMMR tumors, respectively), and the updated median OS is 17.7 months (17.2 months and not reached for MSS/pMMR and MSI-H/dMMR tumors, respectively). No new safety signals were detected. With continued follow-up, this phase Ib/II study that included primarily patients with MSS/pMMR advanced endometrial carcinoma continues to demonstrate efficacy not previously achieved with pembrolizumab monotherapy in this “immunologically cold” tumor. A phase III trial of lenvatinib plus pembrolizumab compared to chemotherapy is ongoing.

 

Novel drug traffics non-conventional T to cells tumors

(503) Clinical Activity of ICT01, an anti-BTN3A-Targeted, γ9δ2-Activating mAb, Alone and in Combination with Pembrolizumab in Patients with Advanced/Refractory Solid Tumors: EVICTION Trial

Martin Wermke, MD (Technical University, Dresden) described clinical evidence that treatment with an antibody targeting butyrophilin-3A (ICT01) leads to tumor infiltration by the non-conventional cytotoxic γ9δ2 T cell subset.  In the ongoing phase I/IIa EVICTION trial, dose-escalation of ICT01 (20µg to 200mg) has been completed as well as three dose cohorts of ICT01 (700µg, 2mg, or 7 mg) plus pembrolizumab. Blood samples were collected and tumors were biopsied for analysis at baseline and on day 28. No dose-limiting toxicities were observed in any of the completed cohorts. Treatment mediated  trafficking of γ9δ2 T cells out of circulation with, associated intra-tumoral increases in total γδ (3 to 34-fold), CD3+ (3 to 55-fold) and CD8+ T cells (1.3 to 66-fold). Stable disease as measured by RECISTv1.1 was observed in 6 of 19 evaluable patients in the dose-escalation cohort and 5 of 8 evaluable patients in the combination cohort. Furthermore, 2 of 8 patients in the combination cohort had a PR. One patient notably had shrinkage of an intracranial metastatic melanoma lesion in a patient refractory to prior ipilimumab plus nivolumab after initial pseudoprogression. These preliminary data suggest that ICT01 effectively mobilizes γ9δ2 T cells to tumors and clinical benefit may be enhanced when combined with pembrolizumab.

 

Autoantigen driving immune-related myocarditis identified

(805) Clonal, activated CD8+ T cells recognizing cardiac alpha-myosin drive immune checkpoint inhibitor associated myocarditis in mice

Margaret Axelrod, BS (Vanderbilt University) presented a new murine model of checkpoint inhibitor-induced myocarditis that led to the identification cardiac alpha-myosin as a key autoantigen driving this rare but often deadly toxicity. Mice with homozygous knockouts of the gene encoding PD-1 and heterozygous deletion of the CTLA-4 encoding locus spontaneously develop fatal myocarditis that recapitulates the clinical features of human immune-mediated toxicity. Depletion of either CD4+ or CD8+ T cells rescued survival in mice, but single cell RNA/T cell receptor sequencing identified CD8+ T cells as the dominant population in the cardiac immune infiltrate. Reporter assays confirmed that the most clonally expanded receptors recognized epitopes of alpha-myosin. This study is the first identification of a candidate autoantigen in checkpoint blockade-associated-myocarditis and efforts are underway to determine if human T cell receptors isolated and sequenced from patient samples also recognize similar epitopes.

 

Gut microbiota contribute  to colorectal cancer immune contexture

(839) Microbiota-specific T follicular helper cells drive tertiary lymphoid structure formation and anti-tumor immunity in colorectal cancer

Abigail Overacre-Delgoffe, PhD (University of Pittsburgh) discovered  that T cells specific to individual constituents of the gut microbiota are involved in anti-tumor immunity. In a carcinogen-induced model of colorectal cancer, mice colonized by the enterohepatic pathogen Helicobacter hepaticus was associated with decreased tumor burden and prolonged survival compared to uncolonized controls. Tumors isolated from H. hepaticus-colonized animals displayed mature peri- or intra-tumoral tertiary lymphoid structures, which were associated with high levels of infiltration of cytotoxic T and NK cells. Depletion of CD8+ T cells did not attenuate the anti-tumor effects of colonization with H. hepaticus, however, CD4+ T follicular helper cells were necessary and sufficient to slow tumor growth. These data reveal unappreciated roles for the microbiota as well as CD4+ T follicular helper cells in modulating the tumor immune microenvironment, possibly paving the way toward new therapeutic targets.

 

Sex differences shape the tumor microenvironment in pancreatic cancer

(885) Targeting FPR2 as a novel approach for immunotherapy in pancreatic cancer female patients – Studies of sexual immune dimorphism in the tumor microenvironment

Dhifaf Sarhan, PhD (Karolinska Institutet) identified a sex-specific mechanism of myeloid-cell driven immune exhaustion that contributes to the immunologically cold phenotype of pancreatic cancer. Interrogation of murine and human transcriptomic data showed elevated expression of G-coupled protein receptor formyl peptide receptor 2 (FPR2) in pancreatic tumor samples compared to healthy tissues. FPR2 was also higher in women than in men. FPR2-expressing myeloid cells in tumors were associated with distinct sex-specific immunophenotypes for both mice and humans, with an immune-excluded phenotype predominating in females versus an immune-ignored phenotype in males. In vitro, myeloid cells treated with FPR2 agonist induced TIM3 and PD-1 on T cells isolated from women but not from men. Knockout of FPR2 slowed subcutaneously injected pancreatic tumor growth to a significantly greater extent in female mice compared to males. Data from human patients with pancreatic cancer and other gastric malignancies confirmed an association between FRP2 expression and poor survival outcomes in women only. This study opens the door to sex-specific personalized immunotherapy approaches and reveals myeloid FPR2 as a new microenvironmental mediator involved in T cell exhaustion in women.

 

First human experience with CAR-transduced macrophages reported

(951) A Phase 1 first in human study of adenovirally transduced anti-HER2 CAR Macrophages in subjects with HER2 overexpressing solid tumors: preliminary safety, pharmacokinetics, and TME reprogramming data

Kim Reiss, MD (University of Pennsylvania) reported the first-in-human experience with adoptive therapy with CAR-transduced macrophages. To date, two patients have been treated with CT-0508, an autologous adoptive cell therapy consisting of monocyte-derived proinflammatory macrophages expressing an anti-HER2 CAR. For manufacturing, patients received four doses of filgrastim for monocyte mobilization prior to apheresis and adenoviral delivery of an anti-HER2 CAR. Treatment was well-tolerated, with no dose-limiting toxicities and no therapy-related toxicities of grade 4 or greater. One participant developed grade 2 CRS three days post-infusion, which resolved on the same day. Transcriptomic analysis of tumor tissue samples revealed rapid recruitment of inflammatory innate immune and naïve T cells by 8 days after infusion. By the 4-week timepoint, significant infiltration by activated and proliferating CD8+ T cells were observed. The trial is continuing to recruit patients, and the data thus far continue to indicate that CT-0508 elicits favorable changes in the tumors.

Wednesday, June 16, 2021

Letter From the Editor - June


Hello JITC Readers,

This edition of the JITC Digest is extra special because June is Cancer Immunotherapy Month™. As JITC readers, you are already aware of the transformational impact of immunotherapy and we welcome you to take advantage of the myriad educational growth and professional development opportunities for clinicians, researchers, and patients offered by SITC during June.
 
June has already been a banner month for immunotherapy, especially for our clinical colleagues. Those of you who attended the American Society for Clinical Oncology Annual Meeting just a few weeks ago—or who followed JITC’s Twitter commentary—likely saw the panoply of oral abstracts, posters, plenary addresses, and education sessions all featuring impressive data showing benefit for a variety of immunotherapy approaches across numerous disease settings. If the results of RELATIVITY have you seeking more information on LAG3 or other targets, be sure to revisit JITC’s Immune Checkpoints Beyond PD-1 Series.
 
Of course, the clinical successes of immunotherapy stemmed from years of basic and translational research, more of which is needed to bring about the next generation of therapeutic agents to overcome resistance and expand the population of patients that may benefit. This month’s original research offers insight into mechanisms of resistance to a variety of immunotherapeutic modalities, with intriguing implications for future development.
 
Francisco J Cueto et al uncover paradoxical inhibition of Flt3L-mediated tumor clearance mediated by a surface receptor involved in cross-priming. Improved tumor control in mice with a novel, extended half-life recombinant IL-15 is demonstrated by Takahiro Miyazaki and colleagues. For the first time, hypoxia is shown to mediate anti-PD-1 resistance in head and neck cancer by Dan P Zandberg et al. Finally, Zhiliang Bai and colleagues identify functional differences in CAR T cells generated from healthy donors and patients.
 
After reading this month’s JITC, continue to celebrate Cancer Immunotherapy Month™ by supporting our sister journals in the immunotherapy space. You can find links to other specialized publications aiming to advance the field forward in this month’s special highlights section.
 
Best regards,

Pedro J. Romero, MD
Editor-in-Chief, Journal for ImmunoTherapy of Cancer

To view the entire April 2021 JITC Digest, please click here

Monday, June 7, 2021

June President's Message: Mentoring a Generation of Researchers, a Conversation with Dr. Steven A. Rosenberg

Dear Colleagues,

Before I announce this month’s fireside chat companion, I wanted to make sure you all have had the opportunity to view the recently published diversity panel discussion on barriers to Asians and Pacific Islanders in medicine and research. This program, conducted in collaboration with the Chinese American Hematologic and Oncologist Network (CAHON) and the Indo-American Cancer Association (IACA), was completed in conjunction with the SITC Diversity and Inclusion Task Force’s efforts to raise awareness of barriers that exist within our field for under-represented minorities. Such conversations can be a tremendous learning tool for leaders in institutions around the world, and I look forward to our society continuing the discussion on this and other related topics into the future. Please click here to view the panel discussion.

June is Cancer Immunotherapy Month™, and I could not think of a better scientist and person to host for this month’s fireside chat than Steven A. Rosenberg, MD, PhD. Dr. Rosenberg is a Senior Investigator in the Surgery Branch at the National Cancer Institute with more than 40 years of experience. You can click the link in the preceding sentence to view his official biography, but as you all likely know already, Dr. Rosenberg is among the most influential scientists in our field’s history. He has been – and continues to be – a mentor to countless researchers through the years, including myself. To recognize his contributions to the field, SITC last year established the Rosenberg Scholars Award, an honor he and I discussed in our chat.


I pulled out a small portion of my discussion with Dr. Rosenberg and inserted below for the purposes of this message, but I highly recommend viewing the entire chat on the SITC YouTube channel here.

Myself: What do you think the future holds (for cancer care) 10, 20, 30 years from now? …What do you think the treatments will be then?

Dr. Rosenberg: So we’ve had surgery with us for over 2,000 years, there are Egyptian papyri that talk about cancer being cut out. We’ve had chemotherapy, which we date to chemical warfare research during the Second World War in 1942, where nitrogen mustard caused laboratory workers to be exposed accidentally, would develop lymphopenias that led to the first application of chemotherapy for cancer. Radiation therapy dated from the year after (Wilhelm) Roentgen discovered x-rays in 1895, so we’ve had these treatments around and they’ve constantly been improved over time, but these have been tiny improvements.

We’re confronted today still with the situation that tells us that if you have metastatic cancer from anyone of these solid epithelial tumors, you’re not going to be cured by anything that’s now available. But we have examples with checkpoint modulators, you can get durable responses, with immunotherapy durable responses, and I would imagine all three of those original treatments will continue to be improved.

The discussion featured a number of topics, including his background and interest in cancer research, the state of cancer vaccines, words of wisdom for young investigators and much more. I hope you all enjoy the conversation as much as I did. Thanks again to Dr. Rosenberg for joining for this month’s fireside chat.

Sincerely,



 








Patrick Hwu, MD

SITC President

Wednesday, May 19, 2021

Letter From the Editor - May


Dear JITC Readers,

Welcome to the latest edition of the JITC Digest. Astute readers have likely noticed that this month’s digest is debuting a new feature. In addition to the usual programming—exciting new publications in JITC—the digest will now also highlight popular papers from the journal archive.
 
This month, we have four original research articles that offer novel insight on one of our field’s most challenging obstacles: resistance to therapy. Addressing immunotherapy resistance is a priority for the field as a whole, and the Society for Immunotherapy of Cancer is spearheading efforts toward developing uniform clinical definitions of resistance as well as support the basic and translational research in order to understand and overcome the mechanistic underpinnings.
 
Barbara Manzanares-Martin and colleagues reveal a surprising association between genomic heterozygosity for the killer-cell immunoglobin-like receptor and overcoming KRAS mutation-mediated resistance to cetuximab.
 
Disease that develops resistance to anti-PD-1 therapies is often highly challenging to treat, but results from two early phase trials in this month’s digest may offer patients new options. Brendan D Curti et al show safety and promising efficacy with the combination of a novel galectin antagonist and pembrolizumab for melanoma and head and neck cancer. Intratumoral injection of the oncolytic poliovirus PVSRIPO led to complete regressions even in uninjected lesions in some patients with melanoma in a phase I trial reported by Georgia M Beasley et al.
 
Finally, Michael W Knitz and colleagues provide deep mechanistic characterization of the interplay between dendritic cells and regulatory T cells that causes head and neck cancers to remain stubbornly immunologically cold after radioimmunotherapy.
 
Be sure to browse this month’s highlight of classic papers as well as the new original research—perhaps perspective from the archives may help spark novel insight into a new finding or vice versa.
 
Best regards,

Pedro J. Romero, MD
Editor-in-Chief, Journal for ImmunoTherapy of Cancer

To view the entire April 2021 JITC Digest, please click here

Monday, May 3, 2021

April/May President's Message: ARPA-H and Cancer Moonshot: A Chat with NCI Director Dr. Ned Sharpless

 Dear Colleagues,

As I am sure many of you saw, U.S. President Joe Biden recently announced as part of his administration’s budget plans to make considerable investment in research. The budget includes a request of $6.5 billion for the creation of a new health agency, the Advanced Research Projects Agency-Health (ARPA-H). According to many news reports, ARPA-H would reside within the National Institutes of Health and have a major focus on cancer, among other diseases.

To gain a better understanding of ARPA-H and a host of other topics involving the state of cancer research in the U.S., I recently hosted National Cancer Institute (NCI) Director Norman E. “Ned” Sharpless, MD for a fireside chat. I enjoyed my chat with Dr. Sharpless, which included discussion of the effect SARS-CoV-2 and the pandemic have had on the NCI, the role immunotherapy is playing in the advancement of cancer patient care in the U.S., the role the NCI can play in supporting promising areas of research and much more.

 

 

Watch the Entire SITC Fireside Chat

I’ve pulled a small portion of our chat, transcribed and inserted below, but I hope you have the time to listen to the full discussion, which you can view here.

Myself: As you know, SITC is an immunotherapy organization, and we appreciate you’ve spoken at our national meetings before, so thank you for that. Tell us about the National Cancer Institute, your views on immunotherapy and the importance of immunotherapy in the treatment of cancer.

Sharpless: Now I really talk about this fourth modality that we have – chemotherapy this kind of classical cytotoxic chemotherapy, surgery, radiation and this whole new toolbox of immunotherapy approaches. I think a really important thing for the NCI is how to support the clinical trials in the development of these agents, which is complicated and a lot of the paradigms have to change, measuring things like response and resistance to immunotherapy agents as some of the traditional approaches don’t apply as you know. But also I think we really have to continue to fund the basic science that supports the basic understanding of the immune system and its interaction with cancer, is still an area that I think is fascinating biology, and some of the new technologies, like single cell sequencing and new medicinal chemistry approaches, are really impactful in that area. It’s exciting to wed these new technologies to a really important problem like tumor immunology.

I also think there’s a role for the NCI for certain kinds of support of the clinical development of certain kinds of agents. The pharmaceutical industry does a really good job of combining PD-1 inhibitors with other agents. That’s a trial that Merck and others do very well, maybe not a high priority for the NCI unless it’s a really complicated trial or complicated agent, but where think there is a possible need for more support for the National Cancer Institute is around cellular immunotherapy trials, which is still quite challenging because of the manufacturing, regulatory and compliance issues, so I think there is a place where if the federal government can help de-risk these technologies a little more, by showing that they work, and particularly allowing trials to be multi-institutional. A single institution study is not nearly as convincing as something that the same CAR construct that can be done in multiple places with beneficial effect. So I think that’s an area where the federal government has a specific role to facilitate a very important kind of clinical research in immuno-oncology.

I think the suite of activities at the NCI now is very robust. As you know, the Cancer Moonshot which began in 2017, has a major focus on cancer immunology, both in adults and children, both in basic science and translational and clinical work. I think it’s really an established modality now and it’s important that the NCI work with groups like SITC to advance that mission.

Thank you very much to Dr. Sharpless for dedicating his time to speak about a range of important issues. I know our society looks forward to finding new and engaging ways our organization can collaborate with the NCI in the future. I also hope we get to see and hear from Dr. Sharpless in person during the 36th Annual Meeting & Pre-Conference Programs (SITC 2021), scheduled to take place Nov. 10–14 at the Walter E. Washington Convention Center in Washington, D.C., and virtually for those who cannot attend in person. I look forward to seeing the SITC family in D.C. this fall.

Sincerely,















Patrick Hwu, MD

SITC President

Friday, April 30, 2021

SITC Meeting Report: April 29 FDA ODAC Summary

The Society for Immunotherapy of Cancer (SITC) is pleased to present this report on the April 29, 2021, meeting of the U.S. Food and Drug Administration (FDA) Oncologic Drugs Advisory Committee (ODAC).

Gastric and Gastroesophageal Junction Adenocarcinoma

In 2017, anti–PD-1 pembrolizumab was granted an accelerated approval for the treatment of patients with recurrent locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (combined positive score [CPS] greater than or equal to 1) as determined by an FDA-approved test, and have failed two or more lines of therapy including fluoropyrimidine- and platinum-containing chemotherapy and, if appropriate, human epidermal growth factor receptor 2 (HER2)/neu-targeted therapy. Approval was granted based on an observed 13.3% objective response rate (ORR) within Cohort 1 of KEYNOTE-059. However, both KEYNOTE-061 (second-line pembrolizumab vs. paclitaxel) and KEYNOTE-062 (first-line pembrolizumab in combination with 5-fluorouracil and cisplatin vs. chemotherapy alone) have failed to confirm an overall survival (OS) benefit of adding the PD-1 inhibitor to the treatment regimens for patients with PD-L1+ gastric or GEJ adenocarcinoma.

Pembrolizumab

On April 29, 2021, FDA ODAC met to discuss maintaining the indication for third-line pembrolizumab monotherapy for PD-L1+ patients with gastric or GEJ adenocarcinoma in light of currently available clinical trial data as well as the rapidly evolving treatment landscape for this patient population. The committee voted 6-2 to recommend rescinding the current indication.

Sponsor Position:

  • Pembrolizumab monotherapy addresses a significant unmet medical need for treatment of heavily pre-treated patients who may not be able to tolerate chemotherapy
  • Data provided by KEYNOTE-059 are consistent with data supporting alternative approvals in this patient population with a generally poor prognosis (ex. median OS is 6 months across clinical trials currently supporting treatment approvals)
  • Pembrolizumab has an acceptable safety profile and is well tolerated in the third-line, PD-L1+ patient population
  • By 2024, four ongoing clinical trials will provide data that may be able to confirm pembrolizumab clinical benefit in this patient population
  • KEYNOTE-061 may not serve as appropriate comparisons for approval confirmation, as more recent data suggest earlier lines of gastric and GEJ treatment require chemotherapy addition
  • KEYNOTE-590 data revealed an OS benefit of pembrolizumab addition to chemotherapy for the treatment of patients with esophageal or GEJ adenocarcinoma and supported FDA approval for first-line treatment

FDA Position:

  • Recent approvals, including first-line PD-1 inhibitor nivolumab + FOLFOX or CAPEOX for patients with gastric and GEJ adenocarcinoma, may address the unmet medical need served by the discussed pembrolizumab indication
  • ORR within the PD-L1+ patient population from Cohort 1 of KEYNOTE-059 may have been contaminated through the inclusion of patients with unknown tumor microsatellite instability/tumor mutational burden status
  • Ongoing clinical trials by the sponsor evaluate pembrolizumab in combination with chemotherapy and are not assessing monotherapy as described within the current indication
  • Given the low ORR demonstrated within KEYNOTE-059, the risk/benefit may not support approval given possibility of immune-related adverse events

Public Comment:

  • This treatment addresses and unmet medical need for patients in third-line setting who have not received IO and those who cannot tolerate chemotherapy

Committee members cited currently available clinical trial data as not supporting the risk/benefit ratio of retaining the indication. They also noted that none of the currently ongoing clinical trials would serve to answer whether pembrolizumab monotherapy provides clinical benefit. Lastly, there was discussion on how recent first-line immunotherapy indications would likely become standard of care, and that future patients requiring third-line treatment may not be eligible for checkpoint inhibitor therapy. Given the recommendation to rescind the indication, committee members emphasized the importance of delaying any planned market removal to ensure that patients currently receiving the therapy could enter into an expanded access program or single patient IND to continue treatment. The FDA was in support of these measures and emphasized that they were cognizant of the impact upon patients if the indication were to be ultimately rescinded.


Hepatocellular Carcinoma

Anti PD-1 nivolumab, the first checkpoint inhibitor to be marketed for treatment of patients with hepatocellular carcinoma (HCC) whose disease progresses after treatment with the first-line vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) sorafenib, gained accelerated approval in September 2017. Approval was based on the results of one of the treatment arms of the multicenter, open-label, phase I/II trial CheckMate 040, which showed a confirmed ORR in this patient population of 14.3% (95% CI: 9.2, 20.8), with 91% of responders having responses lasting 6 months or longer and 55% having responses lasting 12 months or longer. A second anti-PD-1 agent, pembrolizumab, received accelerated approval for the same indication based on an independent central review-assessed ORR of 17% (95% CI: 11, 26) with 89% of responders having durations of 6 months or longer and 56% having response durations of 12 months or longer in the single-arm, multicenter, phase I/II study KEYNOTE-244.

Advanced HCC is associated with a very poor prognosis and the disease almost always develops against a background of cirrhosis, complicating therapy selection in patients with poor liver function and high burden of comorbidities. Since the initial accelerated approvals of pembrolizumab and nivolumab, the treatment landscape for HCC has changed, with the combination of the anti-PD-L1 atezolizumab plus the anti-VEGF bevacizumab attaining full approval for first-line treatment of HCC based on significant OS and PFS improvements in the multi-center, open-label IMbrave150 trial. However, up to 15% to 20% of patients with HCC cannot be treated with bevacizumab due to bleeding risk. Nivolumab in combination with anti-CTLA-4 ipilimumab also received accelerated approval for patients with HCC who have been previously treated with sorafenib in March 2020. This indication was not under consideration at this meeting.

Review of the HCC indications for nivolumab and pembrolizumab monotherapies was motivated by the low response rates in their respective registration studies as well as failure to verify clinical benefit in the designated confirmatory studies CheckMate 459, which did not meet efficacy thresholds for OS benefit in the first-line setting, and KEYNOTE-240, which did not achieve pre-specified statistically significant OS improvement in the identical to the registration trial post-sorafenib setting.

Pembrolizumab

On April 29, 2021, FDA ODAC voted 8 to 0 in favor of maintaining the accelerated approval of pembrolizumab for patients with HCC who have previously been treated with sorafenib. The unanimous decision was based on the substantial unmet need for second-line immunotherapy options in the population ineligible for bevacizumab treatment as well as the panel’s opinion that KEYNOTE-240 demonstrated clinically meaningful benefit despite not meeting pre-specified significance thresholds in OS.

Sponsor Position:

  • Pembrolizumab monotherapy represents an important option for the significant proportion of patients with HCC who cannot receive first-line bevacizumab and whose disease progresses after sorafenib
  • The incremental benefit of second-line pembrolizumab is analogous to the approved second-line TKIs, and the toxicities associated with pembrolizumab monotherapy are largely manageable
  • Durable responses seen with pembrolizumab monotherapy are clinically meaningful

FDA Position:

  • ORR with pembrolizumab monotherapy was low in the registration trial KEYNOTE-244 and the confirmatory trial KEYNOTE-240
  • Recognizing that the bevacizumab-ineligible population represents a significant unmet need, patients at high risk for bleeding with bevacizumab were not included in KEYNOTE-244 and KEYNOTE-240

Public Comment:

  • HCC is associated with very poor prognosis and significant unmet need, especially for the patients with poor underlying liver function or who cannot receive first-line atezolizumab + bevacizumab due to bleeding risk
  • Removing options for second-line therapies is not in the best interest of patients with HCC

Alternative confirmatory trials for pembrolizumab have completed accrual and results are anticipated soon. Specifically, the final analysis of KEYNOTE-394, which is evaluating benefit in the post-sorafenib setting in an East Asian population is expected as early as June or July of 2021, and the results of the LEAP-002 trial comparing first-line pembrolizumab in combination with the VEGF-TKI lenvatinib to lenvatinib monotherapy will be available in 2023.

Nivolumab

In a 4 to 5 vote, ODAC recommended rescinding the indication for nivolumab for the treatment of patients with HCC and prior sorafenib therapy. There was unanimous agreement from committee members that voting was difficult due to the many factors, including the earlier vote to maintain the indication for pembrolizumab monotherapy. Those in favor of continued accelerated approval for nivolumab in this patient population highlighted the unmet need for second-line options. Rationale against continuing the indication centered on the lack of OS benefit in CheckMate 459 and the inadequacy of the proposed alternative studies to generate satisfactory evidence for efficacy in the second-line setting. Discussion also narrowed in on whether data exist to recommend nivolumab monotherapy over an ipilimumab + nivolumab combination regimen, including debate over whether the group of patients deemed unfit for the dual checkpoint inhibitor combination represent a new indication that was not formally defined nor evaluated in trials to date.

Sponsor Position:

  • Nivolumab fills an unmet medical need for the patients who cannot receive bevacizumab in the first-line and whose disease progresses after TKI therapy
  • Nivolumab monotherapy is well-tolerated in patients with HCC and associated with fewer toxicities than the ipilimumab-containing combination regimen
  • Exploratory analyses in CheckMate 459 favor benefit for healthcare-related quality of life with nivolumab
  • Delayed benefit was seen at longer follow-up in CheckMate 459, possibly due to subsequent systemic therapy use in sorafenib arm, including immunotherapy

FDA Position:

  • Availability of first-line atezolizumab + bevacizumab (in addition to other second-line options, including combination ipilimumab + nivolumab) has changed the HCC treatment landscape
  • Statistically significant OS benefit with nivolumab monotherapy was not shown in the designated confirmatory trial, CheckMate 459
  • Alternative confirmatory trials CheckMate 9DX (adjuvant nivolumab) and CheckMate 9DW (first-line ipilimumab + nivolumab) will not provide evidence for benefit with second-line monotherapy
  • Data are lacking on efficacy of the monotherapy in the population of patients who cannot tolerate first-line bevacizumab as well as those deemed ineligible for other second-line therapies, such as ipilimumab + nivolumab

Public Comment:

  • Nivolumab monotherapy is an important option for many HCC patients, especially given the increased potential for toxicity with ipilimumab-containing combinations
  • The safety and adverse event profile of nivolumab is favorable compared to other available second-line therapies for HCC

The FDA is not required to implement the recommendations of ODAC. Committee members also noted that nivolumab is widely available for other FDA-approved indications and that off-label use remains a possibility for the patients with second-line HCC. If the indication were to be ultimately rescinded, expanded access programs and single patient INDs also remain possibilities to allow for continued access.