CIOS 2017

ORLANDO – Patients with metastatic melanoma who have high blood levels of the soluble form of the programmed death-ligand 1 (sPD-L1) have poor clinical outcomes, decreased overall survival, and disease that is resistant to PD-L1 checkpoint inhibitors, compared with patients with low levels of sPD-L1, investigators have found.

High sPD-L1 levels are also associated with an immunosuppressive disease phenotype and with higher levels of pro-inflammatory cytokines, said Roxana S. Dronca, MD, from the Mayo Clinic in Rochester, Minn.

Tumor-induced immune suppression

Membrane-bound, tumor associated PD-L1 has been shown to play a key role in tumor-induced immunosuppression in melanoma and many other malignancies. Expression of PD-L1 on tumors has been shown to be associated with more aggressive tumor biology and with decreased survival in various tumor types, and it was previously thought to be prognostic, she said.

“However, other investigators more recently have found that expression of PD-L1, for instance in metastatic melanoma, is associated with improved survival, possibly reflective of endogenous anti-tumor immunity. So, therefore, the prognostic role of tumor associated PD-L1 is unclear. And also, PD-L1 has been found to be a suboptimal predictive biomarker for response to PD-1 blockade, likely due to heterogeneous and dynamic expression in the tumor tissues, which really cannot be captured with a single-time-point, random tumor biopsy,” she added.

In 2011, Mayo investigators reported on the presence of sPD-L1 (then called B7-H1) in the sera of patients with advanced renal-cell carcinoma and that it was associated with advanced tumor stage and negative clinicopathologic tumor characteristics.

“It seems that the molecule is biologically able to engage PD-1 on circulating T cells, and therefore, it may represent an unanticipated contributing factor to immune homeostasis beyond the tumor microenvironment,” Dr. Dronca said.
 

Higher levels correlate with outcomes

To see whether sPD-L1 levels are related to outcome and response to immune checkpoint inhibitor therapy in patients with metastatic melanoma, the investigators collected baseline peripheral blood samples from 276 patients with advanced melanoma prior to enrollment in nonimmunotherapy clinical trials, as well as samples from 36 healthy blood donors at their center.

They also evaluated samples from 80 patients who were undergoing anti-PD-1 based immunotherapy, with peripheral blood collected at baseline and each subsequent radiographic tumor evaluation, and serial monthly blood samples from healthy pregnant women (number not specified), with samples taken at 2 hours and at 6 weeks post delivery. Levels of PD-L1 were measured by enzyme-linked immunosorbent assay.

The investigators first observed that sPD-L1 levels rose steadily during pregnancy then fell sharply after delivery, showing the presence of PD-L1 levels in healthy subjects and in a normal model of immune tolerance (that is, pregnancy). This finding is not especially surprising given that PD-L1 was first cloned from human placentas, where it is present in abundant levels and forms a barrier at the fetal-maternal interface, Dr. Dronca said.

They also found that sPD-L1 was significantly higher among melanoma patients than among controls, with a mean level of 1.73 ng/mL, compared with 0.77 ng/mL in controls.

Using receiver operating characteristic analysis, the researchers determined a cutoff value of 0.239 ng/mL to distinguish between low and high levels of sPD-L1.

They found that melanoma patients with levels above 0.293 ng/mL had a median overall survival of 11.3 months, compared with 14.8 months for those with levels of 0.293 ng/mL or lower (P = .04).

They also found that high sPD-L1 levels were associated with resistance to anti-PD-1 therapy. Patients who had complete or partial objective responses had a mean level of 0.3 ng/mL, whereas patients who had unequivocal disease progression at 12 weeks had levels 7.5 times higher.

“Interestingly, at 12 weeks the levels were actually quite stable, both in responders and progressors, suggesting that, maybe, soluble PD-L1 is not only a direct reflection of the tumor load, but as mentioned, it can be released by other immune cells and is possibly a more global marker of immune dysfunction,” Dr. Dronca said.
 

‘A little bit curious’

Douglas G. McNeel, MD, PhD, from the University of Wisconsin–Madison, the invited discussant, commended the authors for their study and noted that it raises important questions about the role of PD-L1 in healthy and malignant cells.

[email protected]

ORLANDO – Patients with metastatic melanoma who have high blood levels of the soluble form of the programmed death-ligand 1 (sPD-L1) have poor clinical outcomes, decreased overall survival, and disease that is resistant to PD-L1 checkpoint inhibitors, compared with patients with low levels of sPD-L1, investigators have found.

High sPD-L1 levels are also associated with an immunosuppressive disease phenotype and with higher levels of pro-inflammatory cytokines, said Roxana S. Dronca, MD, from the Mayo Clinic in Rochester, Minn.

Tumor-induced immune suppression

Membrane-bound, tumor associated PD-L1 has been shown to play a key role in tumor-induced immunosuppression in melanoma and many other malignancies. Expression of PD-L1 on tumors has been shown to be associated with more aggressive tumor biology and with decreased survival in various tumor types, and it was previously thought to be prognostic, she said.

“However, other investigators more recently have found that expression of PD-L1, for instance in metastatic melanoma, is associated with improved survival, possibly reflective of endogenous anti-tumor immunity. So, therefore, the prognostic role of tumor associated PD-L1 is unclear. And also, PD-L1 has been found to be a suboptimal predictive biomarker for response to PD-1 blockade, likely due to heterogeneous and dynamic expression in the tumor tissues, which really cannot be captured with a single-time-point, random tumor biopsy,” she added.

In 2011, Mayo investigators reported on the presence of sPD-L1 (then called B7-H1) in the sera of patients with advanced renal-cell carcinoma and that it was associated with advanced tumor stage and negative clinicopathologic tumor characteristics.

“It seems that the molecule is biologically able to engage PD-1 on circulating T cells, and therefore, it may represent an unanticipated contributing factor to immune homeostasis beyond the tumor microenvironment,” Dr. Dronca said.
 

Higher levels correlate with outcomes

To see whether sPD-L1 levels are related to outcome and response to immune checkpoint inhibitor therapy in patients with metastatic melanoma, the investigators collected baseline peripheral blood samples from 276 patients with advanced melanoma prior to enrollment in nonimmunotherapy clinical trials, as well as samples from 36 healthy blood donors at their center.

They also evaluated samples from 80 patients who were undergoing anti-PD-1 based immunotherapy, with peripheral blood collected at baseline and each subsequent radiographic tumor evaluation, and serial monthly blood samples from healthy pregnant women (number not specified), with samples taken at 2 hours and at 6 weeks post delivery. Levels of PD-L1 were measured by enzyme-linked immunosorbent assay.

The investigators first observed that sPD-L1 levels rose steadily during pregnancy then fell sharply after delivery, showing the presence of PD-L1 levels in healthy subjects and in a normal model of immune tolerance (that is, pregnancy). This finding is not especially surprising given that PD-L1 was first cloned from human placentas, where it is present in abundant levels and forms a barrier at the fetal-maternal interface, Dr. Dronca said.

They also found that sPD-L1 was significantly higher among melanoma patients than among controls, with a mean level of 1.73 ng/mL, compared with 0.77 ng/mL in controls.

Using receiver operating characteristic analysis, the researchers determined a cutoff value of 0.239 ng/mL to distinguish between low and high levels of sPD-L1.

They found that melanoma patients with levels above 0.293 ng/mL had a median overall survival of 11.3 months, compared with 14.8 months for those with levels of 0.293 ng/mL or lower (P = .04).

They also found that high sPD-L1 levels were associated with resistance to anti-PD-1 therapy. Patients who had complete or partial objective responses had a mean level of 0.3 ng/mL, whereas patients who had unequivocal disease progression at 12 weeks had levels 7.5 times higher.

“Interestingly, at 12 weeks the levels were actually quite stable, both in responders and progressors, suggesting that, maybe, soluble PD-L1 is not only a direct reflection of the tumor load, but as mentioned, it can be released by other immune cells and is possibly a more global marker of immune dysfunction,” Dr. Dronca said.
 

‘A little bit curious’

Douglas G. McNeel, MD, PhD, from the University of Wisconsin–Madison, the invited discussant, commended the authors for their study and noted that it raises important questions about the role of PD-L1 in healthy and malignant cells.

[email protected]

ORLANDO – Patients with metastatic melanoma who have high blood levels of the soluble form of the programmed death-ligand 1 (sPD-L1) have poor clinical outcomes, decreased overall survival, and disease that is resistant to PD-L1 checkpoint inhibitors, compared with patients with low levels of sPD-L1, investigators have found.

High sPD-L1 levels are also associated with an immunosuppressive disease phenotype and with higher levels of pro-inflammatory cytokines, said Roxana S. Dronca, MD, from the Mayo Clinic in Rochester, Minn.

Tumor-induced immune suppression

Membrane-bound, tumor associated PD-L1 has been shown to play a key role in tumor-induced immunosuppression in melanoma and many other malignancies. Expression of PD-L1 on tumors has been shown to be associated with more aggressive tumor biology and with decreased survival in various tumor types, and it was previously thought to be prognostic, she said.

“However, other investigators more recently have found that expression of PD-L1, for instance in metastatic melanoma, is associated with improved survival, possibly reflective of endogenous anti-tumor immunity. So, therefore, the prognostic role of tumor associated PD-L1 is unclear. And also, PD-L1 has been found to be a suboptimal predictive biomarker for response to PD-1 blockade, likely due to heterogeneous and dynamic expression in the tumor tissues, which really cannot be captured with a single-time-point, random tumor biopsy,” she added.

In 2011, Mayo investigators reported on the presence of sPD-L1 (then called B7-H1) in the sera of patients with advanced renal-cell carcinoma and that it was associated with advanced tumor stage and negative clinicopathologic tumor characteristics.

“It seems that the molecule is biologically able to engage PD-1 on circulating T cells, and therefore, it may represent an unanticipated contributing factor to immune homeostasis beyond the tumor microenvironment,” Dr. Dronca said.
 

Higher levels correlate with outcomes

To see whether sPD-L1 levels are related to outcome and response to immune checkpoint inhibitor therapy in patients with metastatic melanoma, the investigators collected baseline peripheral blood samples from 276 patients with advanced melanoma prior to enrollment in nonimmunotherapy clinical trials, as well as samples from 36 healthy blood donors at their center.

They also evaluated samples from 80 patients who were undergoing anti-PD-1 based immunotherapy, with peripheral blood collected at baseline and each subsequent radiographic tumor evaluation, and serial monthly blood samples from healthy pregnant women (number not specified), with samples taken at 2 hours and at 6 weeks post delivery. Levels of PD-L1 were measured by enzyme-linked immunosorbent assay.

The investigators first observed that sPD-L1 levels rose steadily during pregnancy then fell sharply after delivery, showing the presence of PD-L1 levels in healthy subjects and in a normal model of immune tolerance (that is, pregnancy). This finding is not especially surprising given that PD-L1 was first cloned from human placentas, where it is present in abundant levels and forms a barrier at the fetal-maternal interface, Dr. Dronca said.

They also found that sPD-L1 was significantly higher among melanoma patients than among controls, with a mean level of 1.73 ng/mL, compared with 0.77 ng/mL in controls.

Using receiver operating characteristic analysis, the researchers determined a cutoff value of 0.239 ng/mL to distinguish between low and high levels of sPD-L1.

They found that melanoma patients with levels above 0.293 ng/mL had a median overall survival of 11.3 months, compared with 14.8 months for those with levels of 0.293 ng/mL or lower (P = .04).

They also found that high sPD-L1 levels were associated with resistance to anti-PD-1 therapy. Patients who had complete or partial objective responses had a mean level of 0.3 ng/mL, whereas patients who had unequivocal disease progression at 12 weeks had levels 7.5 times higher.

“Interestingly, at 12 weeks the levels were actually quite stable, both in responders and progressors, suggesting that, maybe, soluble PD-L1 is not only a direct reflection of the tumor load, but as mentioned, it can be released by other immune cells and is possibly a more global marker of immune dysfunction,” Dr. Dronca said.
 

‘A little bit curious’

Douglas G. McNeel, MD, PhD, from the University of Wisconsin–Madison, the invited discussant, commended the authors for their study and noted that it raises important questions about the role of PD-L1 in healthy and malignant cells.

[email protected]

ORLANDO – Patients with advanced hematologic malignancies of B-cell lineage had robust immune responses following infusion of a chimeric antigen receptor (CAR)–T-cell construct designed to deliver a specific balance of antigens, investigators reported.

Adults with relapsed or refractory B-lineage acute myeloid leukemia (ALL), non–Hodgkin lymphoma (NHL), and chronic lymphocytic leukemia (CLL) who received a CAR-T cell construct consisting of autologous CD4-positive and CD-8-positive T cells that were transduced separately, recombined, and then delivered in a single infusion had comparatively high overall response and complete response rates, reported Cameron Turtle, MBBS, PhD, from the Fred Hutchinson Cancer Research Center in Seattle.

“We know that patients have a highly variable CD4 to CD8 ratio, so by actually controlling this and separately transducing, expanding, and then reformulating in this defined composition, we’re able to eliminate one source of variability in CAR-T cell products,” Dr. Turtle said at the ASCO-SITC Clinical Immuno-Oncology Symposium.

In preclinical studies, an even balance of CD4-positive and CD8-positive central memory T cells or naive T cells evoked more potent immune responses against B-cell malignancies in mice than CD19-positive cells, he explained

To see whether this would also hold true in humans, the investigators enrolled into a phase I/II trial adults with relapsed/refractory B-cell malignancies, including ALL (36 patients), NHL (41), and CLL (24). No patients were excluded on the basis of either absolute lymphocyte, circulating tumors cells, history of stem cell transplant, or results of in vitro test expansions.

All patients underwent leukapheresis for harvesting of T-cells, and populations of CD4- and CD8-positive cells were separated and transduced with a lentiviral vector to express a CD19 CAR and a truncated human epidermal growth factor receptor that allowed tracing of the transduced cells via flow cytometry. The patients underwent lymphodepleting chemotherapy with cyclophosphamide (for the earliest patients), or cyclophosphamide plus fludarabine. Fifteen days after leukapheresis, the separated, transduced, and expanded cells were combined and delivered back to patients in a single infusion at one of three dose levels: 2 x 105, 2 x 106, or 2 x 107 CAR-T cells/kg.
 

ALL results

Two of the 36 patients with ALL died from complications of the CAR-T cell infusion process prior to evaluation. The 34 remaining patients all had morphologic bone marrow complete responses (CR). Of this group, 32 also had bone marrow CR on flow cytometry.

Using immunoglobulin H (IgH) deep sequencing in a subset of 20 patients 3 weeks after CAR-T cell infusion, the investigators could not detect the malignant IgH index clone in 13 of the patients, and found fewer than 10 copies in the bone marrow of 5 patients.

Six of seven patients with extramedullary disease at baseline had a complete response. The remaining patient in this group had an equivocal PET scan result, and experienced a relapse 2 months after assessment.

The investigators also determined that the lymphodepletion regimen may affect overall results, based on the finding that 10 of 12 patients who received cyclophosphamide alone achieved a CR, but seven of these 10 patients had a relapse within a few months. Of these seven patients. five received a second T-cell infusion, but none had significant T-cell expansion. The investigators traced the failure of the second attempt to a CD8-mediated transgene immune response to a murine single-chain variable fragment used in the construct.

For subsequent patients, they altered the lymphodepletion regimen to include fludarabine to prevent priming of the anti-CAR transgenic immune response. This modification resulted in improved progression-free survival and overall survival for subsequent patients receiving a second infusion, Dr. Turtle said.
 

NHL results

Of the 41 patients with NHL, 30 (73%) had aggressive histologies, including diffuse large B-cell lymphoma, primary mediastinal large B-cell lymphoma, T-cell/histiocyte-rich large B-cell, and Burkitt lymphomas, and 11 (27%) had indolent histologies, including mantle cell and follicular lymphomas. Most of the patients had received multiple prior lines of therapy, and 19 (46%) had undergone either an autologous or allogeneic stem cell transplant.

Of the 39 evaluable patients who completed therapy, the overall response rate was 67%, including 13 (39%) with CR. Dr. Turtle noted that the CR rate was substantially higher among patients who received cyclophosphamide and fludarabine lymphodepletion, compared with cyclophosphamide alone.

There were also a few responses, including two CRs, among patients with indolent histologies, he said.

CLL, safety results

All 24 patients with CLL had previously received ibrutinib (Imbruvica). Of this group, 19 either had no significant responses to the drug, inactivating mutations, or intolerable toxicities. All but 1 of the 24 patients also had high-risk cytogenetics.

Of the 16 ibrutinib-refractory patients who were evaluable for restaging, 14 had no evidence of disease in bone marrow by flow cytometry at 4 weeks. The overall response rate in this group was 69%, which included four CRs.

Among a majority of all patients, toxicity with the CAR-T cell therapy was mild to moderate. Early cytokine changes appeared to be predictive of serious adverse events such as the cytokine release syndrome, a finding that may allow clinicians to intervene early to prevent complications, Dr. Turtle said.

In the CAR-T cell therapy, “multiple things affect the response and toxicity, including CAR T-cell dose, disease burden, the anti-CAR transgene immune response and the lymphodepletion regimen, not to mention other patient factors that we’re still sorting out,” he commented.

The trial was funded by the National Institutes of Health, Life Science Development Fund, Juno Therapeutics and the Bezos Family Foundation. Dr. Turtle disclosed consultancy, honoraria, and/or research funding from Juno Therapeutics and Seattle Genetics.

ORLANDO – Patients with advanced hematologic malignancies of B-cell lineage had robust immune responses following infusion of a chimeric antigen receptor (CAR)–T-cell construct designed to deliver a specific balance of antigens, investigators reported.

Adults with relapsed or refractory B-lineage acute myeloid leukemia (ALL), non–Hodgkin lymphoma (NHL), and chronic lymphocytic leukemia (CLL) who received a CAR-T cell construct consisting of autologous CD4-positive and CD-8-positive T cells that were transduced separately, recombined, and then delivered in a single infusion had comparatively high overall response and complete response rates, reported Cameron Turtle, MBBS, PhD, from the Fred Hutchinson Cancer Research Center in Seattle.

“We know that patients have a highly variable CD4 to CD8 ratio, so by actually controlling this and separately transducing, expanding, and then reformulating in this defined composition, we’re able to eliminate one source of variability in CAR-T cell products,” Dr. Turtle said at the ASCO-SITC Clinical Immuno-Oncology Symposium.

In preclinical studies, an even balance of CD4-positive and CD8-positive central memory T cells or naive T cells evoked more potent immune responses against B-cell malignancies in mice than CD19-positive cells, he explained

To see whether this would also hold true in humans, the investigators enrolled into a phase I/II trial adults with relapsed/refractory B-cell malignancies, including ALL (36 patients), NHL (41), and CLL (24). No patients were excluded on the basis of either absolute lymphocyte, circulating tumors cells, history of stem cell transplant, or results of in vitro test expansions.

All patients underwent leukapheresis for harvesting of T-cells, and populations of CD4- and CD8-positive cells were separated and transduced with a lentiviral vector to express a CD19 CAR and a truncated human epidermal growth factor receptor that allowed tracing of the transduced cells via flow cytometry. The patients underwent lymphodepleting chemotherapy with cyclophosphamide (for the earliest patients), or cyclophosphamide plus fludarabine. Fifteen days after leukapheresis, the separated, transduced, and expanded cells were combined and delivered back to patients in a single infusion at one of three dose levels: 2 x 105, 2 x 106, or 2 x 107 CAR-T cells/kg.
 

ALL results

Two of the 36 patients with ALL died from complications of the CAR-T cell infusion process prior to evaluation. The 34 remaining patients all had morphologic bone marrow complete responses (CR). Of this group, 32 also had bone marrow CR on flow cytometry.

Using immunoglobulin H (IgH) deep sequencing in a subset of 20 patients 3 weeks after CAR-T cell infusion, the investigators could not detect the malignant IgH index clone in 13 of the patients, and found fewer than 10 copies in the bone marrow of 5 patients.

Six of seven patients with extramedullary disease at baseline had a complete response. The remaining patient in this group had an equivocal PET scan result, and experienced a relapse 2 months after assessment.

The investigators also determined that the lymphodepletion regimen may affect overall results, based on the finding that 10 of 12 patients who received cyclophosphamide alone achieved a CR, but seven of these 10 patients had a relapse within a few months. Of these seven patients. five received a second T-cell infusion, but none had significant T-cell expansion. The investigators traced the failure of the second attempt to a CD8-mediated transgene immune response to a murine single-chain variable fragment used in the construct.

For subsequent patients, they altered the lymphodepletion regimen to include fludarabine to prevent priming of the anti-CAR transgenic immune response. This modification resulted in improved progression-free survival and overall survival for subsequent patients receiving a second infusion, Dr. Turtle said.
 

NHL results

Of the 41 patients with NHL, 30 (73%) had aggressive histologies, including diffuse large B-cell lymphoma, primary mediastinal large B-cell lymphoma, T-cell/histiocyte-rich large B-cell, and Burkitt lymphomas, and 11 (27%) had indolent histologies, including mantle cell and follicular lymphomas. Most of the patients had received multiple prior lines of therapy, and 19 (46%) had undergone either an autologous or allogeneic stem cell transplant.

Of the 39 evaluable patients who completed therapy, the overall response rate was 67%, including 13 (39%) with CR. Dr. Turtle noted that the CR rate was substantially higher among patients who received cyclophosphamide and fludarabine lymphodepletion, compared with cyclophosphamide alone.

There were also a few responses, including two CRs, among patients with indolent histologies, he said.

CLL, safety results

All 24 patients with CLL had previously received ibrutinib (Imbruvica). Of this group, 19 either had no significant responses to the drug, inactivating mutations, or intolerable toxicities. All but 1 of the 24 patients also had high-risk cytogenetics.

Of the 16 ibrutinib-refractory patients who were evaluable for restaging, 14 had no evidence of disease in bone marrow by flow cytometry at 4 weeks. The overall response rate in this group was 69%, which included four CRs.

Among a majority of all patients, toxicity with the CAR-T cell therapy was mild to moderate. Early cytokine changes appeared to be predictive of serious adverse events such as the cytokine release syndrome, a finding that may allow clinicians to intervene early to prevent complications, Dr. Turtle said.

In the CAR-T cell therapy, “multiple things affect the response and toxicity, including CAR T-cell dose, disease burden, the anti-CAR transgene immune response and the lymphodepletion regimen, not to mention other patient factors that we’re still sorting out,” he commented.

The trial was funded by the National Institutes of Health, Life Science Development Fund, Juno Therapeutics and the Bezos Family Foundation. Dr. Turtle disclosed consultancy, honoraria, and/or research funding from Juno Therapeutics and Seattle Genetics.

ORLANDO – Patients with advanced hematologic malignancies of B-cell lineage had robust immune responses following infusion of a chimeric antigen receptor (CAR)–T-cell construct designed to deliver a specific balance of antigens, investigators reported.

Adults with relapsed or refractory B-lineage acute myeloid leukemia (ALL), non–Hodgkin lymphoma (NHL), and chronic lymphocytic leukemia (CLL) who received a CAR-T cell construct consisting of autologous CD4-positive and CD-8-positive T cells that were transduced separately, recombined, and then delivered in a single infusion had comparatively high overall response and complete response rates, reported Cameron Turtle, MBBS, PhD, from the Fred Hutchinson Cancer Research Center in Seattle.

“We know that patients have a highly variable CD4 to CD8 ratio, so by actually controlling this and separately transducing, expanding, and then reformulating in this defined composition, we’re able to eliminate one source of variability in CAR-T cell products,” Dr. Turtle said at the ASCO-SITC Clinical Immuno-Oncology Symposium.

In preclinical studies, an even balance of CD4-positive and CD8-positive central memory T cells or naive T cells evoked more potent immune responses against B-cell malignancies in mice than CD19-positive cells, he explained

To see whether this would also hold true in humans, the investigators enrolled into a phase I/II trial adults with relapsed/refractory B-cell malignancies, including ALL (36 patients), NHL (41), and CLL (24). No patients were excluded on the basis of either absolute lymphocyte, circulating tumors cells, history of stem cell transplant, or results of in vitro test expansions.

All patients underwent leukapheresis for harvesting of T-cells, and populations of CD4- and CD8-positive cells were separated and transduced with a lentiviral vector to express a CD19 CAR and a truncated human epidermal growth factor receptor that allowed tracing of the transduced cells via flow cytometry. The patients underwent lymphodepleting chemotherapy with cyclophosphamide (for the earliest patients), or cyclophosphamide plus fludarabine. Fifteen days after leukapheresis, the separated, transduced, and expanded cells were combined and delivered back to patients in a single infusion at one of three dose levels: 2 x 105, 2 x 106, or 2 x 107 CAR-T cells/kg.
 

ALL results

Two of the 36 patients with ALL died from complications of the CAR-T cell infusion process prior to evaluation. The 34 remaining patients all had morphologic bone marrow complete responses (CR). Of this group, 32 also had bone marrow CR on flow cytometry.

Using immunoglobulin H (IgH) deep sequencing in a subset of 20 patients 3 weeks after CAR-T cell infusion, the investigators could not detect the malignant IgH index clone in 13 of the patients, and found fewer than 10 copies in the bone marrow of 5 patients.

Six of seven patients with extramedullary disease at baseline had a complete response. The remaining patient in this group had an equivocal PET scan result, and experienced a relapse 2 months after assessment.

The investigators also determined that the lymphodepletion regimen may affect overall results, based on the finding that 10 of 12 patients who received cyclophosphamide alone achieved a CR, but seven of these 10 patients had a relapse within a few months. Of these seven patients. five received a second T-cell infusion, but none had significant T-cell expansion. The investigators traced the failure of the second attempt to a CD8-mediated transgene immune response to a murine single-chain variable fragment used in the construct.

For subsequent patients, they altered the lymphodepletion regimen to include fludarabine to prevent priming of the anti-CAR transgenic immune response. This modification resulted in improved progression-free survival and overall survival for subsequent patients receiving a second infusion, Dr. Turtle said.
 

NHL results

Of the 41 patients with NHL, 30 (73%) had aggressive histologies, including diffuse large B-cell lymphoma, primary mediastinal large B-cell lymphoma, T-cell/histiocyte-rich large B-cell, and Burkitt lymphomas, and 11 (27%) had indolent histologies, including mantle cell and follicular lymphomas. Most of the patients had received multiple prior lines of therapy, and 19 (46%) had undergone either an autologous or allogeneic stem cell transplant.

Of the 39 evaluable patients who completed therapy, the overall response rate was 67%, including 13 (39%) with CR. Dr. Turtle noted that the CR rate was substantially higher among patients who received cyclophosphamide and fludarabine lymphodepletion, compared with cyclophosphamide alone.

There were also a few responses, including two CRs, among patients with indolent histologies, he said.

CLL, safety results

All 24 patients with CLL had previously received ibrutinib (Imbruvica). Of this group, 19 either had no significant responses to the drug, inactivating mutations, or intolerable toxicities. All but 1 of the 24 patients also had high-risk cytogenetics.

Of the 16 ibrutinib-refractory patients who were evaluable for restaging, 14 had no evidence of disease in bone marrow by flow cytometry at 4 weeks. The overall response rate in this group was 69%, which included four CRs.

Among a majority of all patients, toxicity with the CAR-T cell therapy was mild to moderate. Early cytokine changes appeared to be predictive of serious adverse events such as the cytokine release syndrome, a finding that may allow clinicians to intervene early to prevent complications, Dr. Turtle said.

In the CAR-T cell therapy, “multiple things affect the response and toxicity, including CAR T-cell dose, disease burden, the anti-CAR transgene immune response and the lymphodepletion regimen, not to mention other patient factors that we’re still sorting out,” he commented.

The trial was funded by the National Institutes of Health, Life Science Development Fund, Juno Therapeutics and the Bezos Family Foundation. Dr. Turtle disclosed consultancy, honoraria, and/or research funding from Juno Therapeutics and Seattle Genetics.

ORLANDO – In patients with advanced cervical cancer, combining chemotherapy with a vaccine against human papillomavirus (HPV) type 16 resulted in a robust, T-cell–mediated immune response and long duration survival for a large proportion of patients, reported investigators from the Netherlands.

Patients with advanced, HPV16-positive cervical cancer who were treated with standard chemotherapy and vaccinated with HPV16 synthetic long peptides (HPV16-SLP) had substantially increased T-cell responses, and these responses correlated with survival, said Marij Welters, PhD, from Leiden (the Netherlands) University Medical Center.

Neil Osterweil/Frontline Medical News

Combination required

Although therapeutic vaccination with HPV16-SLP has been shown to evoke T-cell–mediated shrinkage of HPV16-induced cervical neoplasia, the investigators found in a previous study that vaccination did not result in either tumor regression or prolonged progression-free survival of patients with advanced or recurrent HPV16-induced cervical cancer.

In the phase I trial reported here, the investigators explored whether combination HPV16-SLP with chemotherapy could potentiate T-cell responses.

In a second study, Welters et al. also showed that vaccination with HPV16-SLP after the second round of chemotherapy, when myeloid cells were at their nadir, resulted in robust T-cell responses in both mice and humans.

In the phase I trial reported here, the authors reported on the feasibility and efficacy of the technique in a larger cohort of patients with late-stage, HPV16-positive cervical cancer.

The investigators enrolled cohorts of 12 patients each and delivered one HPV16-SLP vaccine dose 2 weeks after the second, third, and fourth cycles of a total of six chemotherapy cycles with carboplatin and paclitaxel. The vaccine was test dosed at levels of 20, 40, 100, and 300 mcg/peptide, with or without 1 mcg/kg of pegylated interferon-alpha at each peptide dose level. The peptides covered the length of the HPV16 E6 and E7 proteins.

“Upon vaccination, we see a very strong T-cell response induced by the vaccine,” Dr. Welters said.

They also tested general immune responses to various microbial antigens and saw no significant differences in responses among the various dose cohorts.

Early response data was available for a total of 59 patients, 35 of whom received the vaccine/chemotherapy combination as first-line therapy and 24 of whom received it in the second line.

Two of the first-line patients had a complete response, as did one patient who received the combination as second-line therapy. Respective rates of partial responses were 22 and 5, stable disease was seen in 9 and 13 patients, and disease progression in 2 and 5 patients.

The overall response rate for patients treated in the first line was 69%, and the combined overall response and stable-disease rates were 94%. Among patients treated in the second line, the respective rates were 25% and 79%.

Median overall survival (OS) from the time of the first chemotherapy dose was 16.8 months among the first-line patients vs. 7.9 months among second-line patients (P = .0110)

At the data cutoff, median OS had not been reached for the two highest peptide dose levels (100 and 300 mcg).

The investigators also found that OS was independent of general immune status among the patients, suggesting that the benefit was derived specifically from induced T-cell responses.

‘Provocative and promising’

Invited discussant Heather McArthur, MD, MPH, from Cedars-Sinai Medical Center, Los Angeles, called the finding “provocative and promising.”

Neil Osterweil/Frontline Medical News

ORLANDO – In patients with advanced cervical cancer, combining chemotherapy with a vaccine against human papillomavirus (HPV) type 16 resulted in a robust, T-cell–mediated immune response and long duration survival for a large proportion of patients, reported investigators from the Netherlands.

Patients with advanced, HPV16-positive cervical cancer who were treated with standard chemotherapy and vaccinated with HPV16 synthetic long peptides (HPV16-SLP) had substantially increased T-cell responses, and these responses correlated with survival, said Marij Welters, PhD, from Leiden (the Netherlands) University Medical Center.

Neil Osterweil/Frontline Medical News

Combination required

Although therapeutic vaccination with HPV16-SLP has been shown to evoke T-cell–mediated shrinkage of HPV16-induced cervical neoplasia, the investigators found in a previous study that vaccination did not result in either tumor regression or prolonged progression-free survival of patients with advanced or recurrent HPV16-induced cervical cancer.

In the phase I trial reported here, the investigators explored whether combination HPV16-SLP with chemotherapy could potentiate T-cell responses.

In a second study, Welters et al. also showed that vaccination with HPV16-SLP after the second round of chemotherapy, when myeloid cells were at their nadir, resulted in robust T-cell responses in both mice and humans.

In the phase I trial reported here, the authors reported on the feasibility and efficacy of the technique in a larger cohort of patients with late-stage, HPV16-positive cervical cancer.

The investigators enrolled cohorts of 12 patients each and delivered one HPV16-SLP vaccine dose 2 weeks after the second, third, and fourth cycles of a total of six chemotherapy cycles with carboplatin and paclitaxel. The vaccine was test dosed at levels of 20, 40, 100, and 300 mcg/peptide, with or without 1 mcg/kg of pegylated interferon-alpha at each peptide dose level. The peptides covered the length of the HPV16 E6 and E7 proteins.

“Upon vaccination, we see a very strong T-cell response induced by the vaccine,” Dr. Welters said.

They also tested general immune responses to various microbial antigens and saw no significant differences in responses among the various dose cohorts.

Early response data was available for a total of 59 patients, 35 of whom received the vaccine/chemotherapy combination as first-line therapy and 24 of whom received it in the second line.

Two of the first-line patients had a complete response, as did one patient who received the combination as second-line therapy. Respective rates of partial responses were 22 and 5, stable disease was seen in 9 and 13 patients, and disease progression in 2 and 5 patients.

The overall response rate for patients treated in the first line was 69%, and the combined overall response and stable-disease rates were 94%. Among patients treated in the second line, the respective rates were 25% and 79%.

Median overall survival (OS) from the time of the first chemotherapy dose was 16.8 months among the first-line patients vs. 7.9 months among second-line patients (P = .0110)

At the data cutoff, median OS had not been reached for the two highest peptide dose levels (100 and 300 mcg).

The investigators also found that OS was independent of general immune status among the patients, suggesting that the benefit was derived specifically from induced T-cell responses.

‘Provocative and promising’

Invited discussant Heather McArthur, MD, MPH, from Cedars-Sinai Medical Center, Los Angeles, called the finding “provocative and promising.”

Neil Osterweil/Frontline Medical News

ORLANDO – In patients with advanced cervical cancer, combining chemotherapy with a vaccine against human papillomavirus (HPV) type 16 resulted in a robust, T-cell–mediated immune response and long duration survival for a large proportion of patients, reported investigators from the Netherlands.

Patients with advanced, HPV16-positive cervical cancer who were treated with standard chemotherapy and vaccinated with HPV16 synthetic long peptides (HPV16-SLP) had substantially increased T-cell responses, and these responses correlated with survival, said Marij Welters, PhD, from Leiden (the Netherlands) University Medical Center.

Neil Osterweil/Frontline Medical News

Combination required

Although therapeutic vaccination with HPV16-SLP has been shown to evoke T-cell–mediated shrinkage of HPV16-induced cervical neoplasia, the investigators found in a previous study that vaccination did not result in either tumor regression or prolonged progression-free survival of patients with advanced or recurrent HPV16-induced cervical cancer.

In the phase I trial reported here, the investigators explored whether combination HPV16-SLP with chemotherapy could potentiate T-cell responses.

In a second study, Welters et al. also showed that vaccination with HPV16-SLP after the second round of chemotherapy, when myeloid cells were at their nadir, resulted in robust T-cell responses in both mice and humans.

In the phase I trial reported here, the authors reported on the feasibility and efficacy of the technique in a larger cohort of patients with late-stage, HPV16-positive cervical cancer.

The investigators enrolled cohorts of 12 patients each and delivered one HPV16-SLP vaccine dose 2 weeks after the second, third, and fourth cycles of a total of six chemotherapy cycles with carboplatin and paclitaxel. The vaccine was test dosed at levels of 20, 40, 100, and 300 mcg/peptide, with or without 1 mcg/kg of pegylated interferon-alpha at each peptide dose level. The peptides covered the length of the HPV16 E6 and E7 proteins.

“Upon vaccination, we see a very strong T-cell response induced by the vaccine,” Dr. Welters said.

They also tested general immune responses to various microbial antigens and saw no significant differences in responses among the various dose cohorts.

Early response data was available for a total of 59 patients, 35 of whom received the vaccine/chemotherapy combination as first-line therapy and 24 of whom received it in the second line.

Two of the first-line patients had a complete response, as did one patient who received the combination as second-line therapy. Respective rates of partial responses were 22 and 5, stable disease was seen in 9 and 13 patients, and disease progression in 2 and 5 patients.

The overall response rate for patients treated in the first line was 69%, and the combined overall response and stable-disease rates were 94%. Among patients treated in the second line, the respective rates were 25% and 79%.

Median overall survival (OS) from the time of the first chemotherapy dose was 16.8 months among the first-line patients vs. 7.9 months among second-line patients (P = .0110)

At the data cutoff, median OS had not been reached for the two highest peptide dose levels (100 and 300 mcg).

The investigators also found that OS was independent of general immune status among the patients, suggesting that the benefit was derived specifically from induced T-cell responses.

‘Provocative and promising’

Invited discussant Heather McArthur, MD, MPH, from Cedars-Sinai Medical Center, Los Angeles, called the finding “provocative and promising.”

Neil Osterweil/Frontline Medical News