Method for inducing early T memory response with short peptides anti-tumor vaccine

Abstract

The present invention relates to a therapeutic peptide T specific immune therapy for use in the treatment of a cancer of an HLA-A2 (Human Leukocyte Antigen A2) positive patient, said treatment comprises a priming period consisting in two to three administrations of said therapeutic peptide T specific immune therapy, thereby inducing a memory T cell response.

Claims

1. A method of treating cancer in an HLA-A2 (Human Leukocyte Antigen A2) positive patient, said method comprising a priming period followed by a maintenance period, the priming period consisting of two or three administrations of a therapeutic peptide T specific immune therapy to said patient every two or three weeks during the priming period, thereby inducing a central memory T cell response, and the maintenance period comprising the administration of said therapeutic peptide T specific immune therapy to said patient every two to three months for at least one year, wherein: the cancer is a Non Small Cell Lung Cancer (NSCLC) expressing at least one tumor antigen selected from the group consisting of HER2/ErbB2, CEA, p53, MAGE2 and MAGE3, and said therapeutic peptide T specific immune therapy comprises the peptides aKXVAAWTLKAAa (SEQ ID No 10), with X and a, respectively, indicating cyclohexylalanine and d-alanine, RLLQETELV (SEQ ID No 1), YLQLVFGIEV (SEQ ID No 2), LLTFWNPPV (SEQ ID No 3), KVFGSLAFV (SEQ ID No 4), KLBPVQLWV (SEQ ID No 5, with B indicating α-aminoisobutyric acid), SMPPPGTRV (SEQ ID No 6), IMIGHLVGV (SEQ ID No 7), KVAEIVHFL (SEQ ID No 8), and YLSGADLNL (SEQ ID No 9).

2. The method according to claim 1, wherein the therapeutic peptide T specific immune therapy consists of the following peptides aKXVAAWTLKAAa (SEQ ID No 10), with X and a respectively indicating cyclohexylalanine and d-alanine, RLLQETELV (SEQ ID No 1), YLQLVFGIEV (SEQ ID No 2), LLTFWNPPV (SEQ ID No 3), KVFGSLAFV (SEQ ID No 4), KLBPVQLWV (SEQ ID No 5), with B indicating α-aminoisobutyric acid, SMPPPGTRV (SEQ ID No 6), IMIGHLVGV (SEQ ID No 7), KVAEIVHFL (SEQ ID No 8), and YLSGADLNL (SEQ ID No 9).

3. The method according to claim 1, wherein said priming period consists of three administrations of said therapeutic peptide T specific immune therapy.

4. The method according to claim 1, wherein said patient suffers from an advanced or late-stage NSCLC.

5. The method according to claim 1, wherein said patient suffers from metastases.

6. The method according to claim 1, wherein said patient has a malignant pleural effusion.

7. The method according to claim 1, wherein the doses of therapeutic peptide T specific immune therapy are administered parenterally.

8. The method according to claim 1, wherein the peptides are emulsified in incomplete Freund's adjuvant, Montanide ISA-51, mineral oil adjuvant, aluminum hydroxide or alum.

9. The method according to claim 1, wherein the amount of each peptide ranges from 0.1 to 10 mg of peptide in each dose.

10. The method according to claim 9, wherein the amount of total peptide in each dose is 5.0 mg.

11. The method according to claim 1, wherein said patient has already received treatment for the cancer prior to treatment with the therapeutic peptide T specific immune therapy.

12. The method according to claim 1, further comprising administering to the patient an anticancer drug and/or radiotherapy.

13. The method according to claim 1, said method comprising the measurement of central T memory cell response after said priming period and prior to the maintenance period.

14. The method according to claim 13, wherein central T memory response is measured using a IFN-γ enzyme-linked immunospot (cultured ELISPOT) assay.

15. The method according to claim 1, wherein the peptides are administered in combination with GM-CSF as an adjuvant.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1: Phase 1/2 W9 W18 magnitude of central memory T cell responses induced by OSE2101.

(2) FIG. 2: Phase 2 Central memory T cells responses induced by OSE2101 for several epitopes through the number of doses.

(3) FIG. 3: Correlation between OSE-2101-induced PADRE HTL responses and CTL/central memory T cell responses.

(4) FIG. 4: Kaplan-Meier estimate of TTP.

EXAMPLES

Example 1

Early Immune Response Though Central Memory T Cells Involvement

(5) In the Phase 1/2 clinical studies, the safety and immunogenicity of a 10-peptide enhanced epitope combination, OSE-2101, rationally designed to induce broad multi-epitope CTL responses in early stage colon and NSCLC patients. In addition to multi-epitope coverage, OSE-2101 also targeted epitopes from five Tumor antigens which are widely expressed on breast, colon and non-small cell lung, ovarian, tumors (CEA, HER-2/neu, p53, MAGE2 and MAGE3) making this product suitable for therapy against different cancer indications. As a source of T-cell helper for CTL induction, the universal HTL epitope Pan DR Epitope was also included and a mineral oil adjuvant was used for the final formulation of this T specific cancer immunotherapy.

(6) Patient eligibility criteria. OSE-2101 was tested in two disease-specific phase I clinical trials enrolling HLA-A2.sup.+ patients with histologically confirmed stage IIB/IIIA NSCLC or stage III colon cancer. All patients were diagnosed as NED within the past 6 months after undergoing standard therapy. Patients met normal laboratory parameters for blood chemistry and white cell counts and had an Eastern Cooperative Oncology Group performance status of 0 or 1. They were excluded if treated with immunomodulatory agents within one month of study entry or with other cancer immunotherapies. Patients with a history of other cancers, except basal or squamous cell carcinoma of the skin or in situ cervical cancer, were also excluded as were patients with concurrent acute medical conditions or specified autoimmune diseases.

(7) Peptides. The immunogenicity of all immune monitoring epitopes was confirmed by stimulating CTL induced by treatment of HLA-A2.1/K.sup.b transgenic mice with a pre-clinical lot of OSE-2101 (standard Elispot assay).

(8) Clinical study design. Both trials were designed as phase 1/2, open label, multi-center, single dose, multiple administration studies to evaluate the safety and immunogenicity of the OSE-2101 immunotherapy. Patients were treated with 1 ml OSE-2101 every 3 weeks for a total of six doses. Each dose was administered subcutaneously in the same vicinity in the deltoid or upper thigh region, or at a contralateral site if local side-effects were observed. The study duration for each completed patient was 18 weeks. Clinical responses or patient survival were not measured in either phase 1/2 studies.

(9) Clinical sample processing. Blood or leukapheresis product was obtained from patients at the pre-treatment, the Week 9 and Week 18 time points, 3 weeks after the third and sixth dose of OSE-2101 respectively. Peripheral blood mononuclear cells (PBMC) were isolated from samples within 24 hours of collection using a FICOLL-PAQUE density gradient and cryopreserved in containers designed to ensure optimal freezing (Mr. Frosty, Nalgene). For use, cells were rapidly thawed at 37° C. then transferred to human AB serum-containing medium for work-up.

(10) Measurement of central T memory cells responses and T effector memory cells. The CTL responses in 16 total patients (10 colon and six NSCLC) were monitored for CTL responses against each epitope and against the wild-type epitope of epitopes analogs. For each patient, the pre-treatment, Week 9 and Week 18 time points were batch-tested in the same experiment to allow pre- versus post-treatment response comparison in the same experiment. Central T memory cells responses were measured using an IFN-γ enzyme-linked immunospot (cultured ELISPOT) assay following in vitro stimulation of PBMC for 10 days with each vaccine epitope. Briefly, PBMC from each time point were stimulated on day 0 with 10 μg/ml of each epitope individually in replicate in 48-well culture plates (2×10.sup.6 PBMC/well). All cultures were fed with rIL-2 (Endogen, Woburn, Mass.; 10 U/ml final concentration) on days 1, 4 and 7. Ten days after initiation of culture, cells were harvested and tested for activity against specific vaccine peptides and corresponding wild-type peptides of vaccine analogs in the T memory ELISPOT assay. Cells were tested in Millipore IP 96-well plates pre-coated with mouse anti-human IFN-γ antibody (Mabtech USA, Cincinnati, Ohio). Five×10.sup.4 cells and 1.25×10.sup.4 cells from each culture were plated in triplicate wells together with 10.sup.5 irradiated autologous PBMC and 10 μg/ml peptide. As a control, CTL were also tested against an irrelevant HLA-A2.1-binding HBV peptide. After 20 hours incubation, T memory ELISPOT plates were developed by performing sequential incubations with biotinylated anti-human IFN-γ antibody (Mabtech USA), Avidin-Peroxidase Complex (APC, Vector Laboratories, Burlingame, Calif.), and 3-amino-9-ethyl carbazole (AEC) substrate (Sigma Aldrich, St. Louis, Mo.). Spot-forming cells (SFC) were enumerated using a computer-assisted image analysis system (Zeiss KS ELISPOT Reader, Carl Zeiss MicroImaging, Thornwood, N.J.). Data is reported as the net SFC per 5×10.sup.4 cells after subtracting spots induced with the irrelevant HBV peptide.

(11) The central T memory cultured ELISPOT assay was qualified using HLA-A2.sup.+ PBMC from patients who demonstrated a recall T effector memory response against an EBV BMLF1 CTL epitope (sequence, GLCTLVAML, SEQ ID NO: 12) under identical stimulation conditions used for testing clinical samples. Specific response generated from these donors were titrated at limiting cell doses and a linear response was measured (correlation coefficient=0.99). The lower detection limit of the assay was determined to be 5 SFC/well and the upper limit was 600 SFC. The inter-experiment reproducibility was evaluated by repeated testing of cryopreserved pre-vaccination PBMC samples from positive donors on separate days, and the coefficient of variation (CV) ranged from 7-12% in these assays. To assess inter-operator reproducibility, two operators tested pre-treatment PBMC from the same patient on different days and the CV was 13-16% at the optimal cell dose. The CV values were considered to be within an acceptable range of variability and strongly supported the use of our assay for analyses of clinical immune responses.

(12) Response criteria. Positive response criteria were established prospectively after analyzing the variability of pre-treatment responses against each epitope and the irrelevant HBV control epitope. The mean SFC response in a post-treatment sample was considered a positive epitope-induced T memory cell response if it met all of the following: 1) was greater than 5 SFC above the irrelevant epitope response, 2) was greater than the mean SFC of the irrelevant epitope response, plus 2 SD, and 3) was two-fold greater than the SFC response in the pre-treatment sample from the same patient, plus 2 SD. The inclusion of “plus two standard deviations” was used to accommodate the assay variability and served to make the criteria more stringent.

(13) Results

(14) Patient characterization. Fourteen patients with stage III colon cancer enrolled in the trial and ten patients completed the study after receiving six doses of OSE-2101. In the NSCLC trial ten patients with stage IIB/IIIA disease were enrolled and six patients completed the study. OSE-2101 was deemed safe and tolerated by patients in the two clinical trials with typical side-effects common to peptides prepared in mineral oil adjuvant being observed.

(15) Immunogenicity of OSE-2101 A total of 16 patients (10 colon cancer and 6 NSCLC) receiving the full course of six OSE-2101 doses were evaluated for the frequency, breadth and magnitude of TAA-specific central T memory cell responses induced by the specific immunotherapy. To improve detection of central memory T cell responses PBMC were stimulated in vitro for 10 days with each epitope. The effector activity of the in vitro expanded PBMC was measured with an IFN-γ ELISPOT assay against the respective epitope and an irrelevant HLA-A*0201-binding HBV epitope. If the epitope was an analog the corresponding wild-type epitope was also tested.

(16) Results from immune monitoring of the 16 patients indicated that OSE-2101 was capable of inducing a wide breadth of central memory T cell responses in patients. In the colon cancer trial, eight of the 10 patients surprisingly generated CTL responses against four or more vaccine epitopes at the Week 9 and/or Week 18 time points (FIG. 1). The average magnitude of the cultured ELISPOT was in the same range between Week 9 and Week 18.

(17) Patient 607 demonstrated the widest breadth and highest magnitude of central T cell memory responses, displaying responses between 60-200 SFC per 5×10.sup.4 cells against seven epitopes at the Week 9 time point. More importantly, five of the seven induced T memory responses in this patient were directed against wild-type epitopes. At the Week 18 time point, patient 607 generated central memory T cell responses, some exceeding 1000 SFC, against six of the same epitopes at Week 9.

(18) Equally noteworthy were the multi-epitope responses observed in colon cancer patients 601, 603, 604 and 606 to five or more epitopes surprisingly at the Week 9 and/or also at Week 18 time points.

(19) Multi-epitope central memory T cell responses were also observed in NSCLC patients, surprisingly at the Week 9 and/or also at Week 18 time points. All of the data described utilized a testing protocol where PBMC samples were cultured in vitro for 10 days with individual OSE-2101 epitopes to expand in vivo-primed CTL prior to testing in the ELISPOT assay and the measure central memory T cell response and the in vitro stimulation step as cultured Elispot was required to see responses to epitopes.

(20) Immunogenicity of different epitope classes. Analysis of the frequency and magnitude of CTL responses indicated that most of the epitopes and all of the epitope classes represented in the product were immunogenic in patients. Overall, eight of the nine vaccine epitopes induced central memory T cell responses in at least one colon cancer patient and six vaccine epitopes were immunogenic in at least one NSCLC patient. Three of the fixed-anchor analogs (CEA.24V9 (SEQ ID No 3), HER2.369V2V9 (SEQ ID No 4) and p53.139L2B3 (SEQ ID No 5)) and two heteroclitic analogs (CEA.691H5 (SEQ ID No 7) and CEA.605D6 (SEQ ID No 9)) were particularly immunogenic as 60-80% of colon cancer patients and 40-80% of the HLA-A*0201-typed NSCLC patients responded to each of the analogs (Table 1A and 1B week 9 or week 18 responses). The heightened immunogenicity of the analogs was also indicated by average response magnitudes ranging from 70-180 SFC at Week 9 and from 90-315 SFC at Week 18 in colon cancer patients (Table 1A) and 60-138 SFC at Week 18 in NSCLC patients (Table 1B).

(21) Immunological testing of the 16 colon and NSCLC patients who completed treatment indicated that OSE-2101 was successful in inducing a wide breadth of CTL and memory T cell responses in individual patients as soon as after 3 injections, characterized by the simultaneous induction of CTL specificities directed against several epitopes. The broad CTL/though central memory T cell responses observed in individual patients in both cohorts indicated the potential long term efficacy for immunotherapy in early and late stage patients. Instead, simultaneous CTL and central Memory T cell responses is addressing a long term clinical benefit of the multi-epitope approach to cancer immunotherapy.

(22) TABLE-US-00001 TABLE 1A A. Summary of CTL responses in 10 colon patients CEA.24V9 CEA.605D6 CEA.691H5 HER2.369L2V9 MAGE2.157 Patient Sample A.sup.a) WT.sup.b) A WT A WT A WT WT 551 Pre-vacc 9.3.sup.c) 18.6 15.6 0.8 0.0 0.0 28.7 1.8 1.3 Week 9 42.7.sup.d) —.sup.e) — — 92.7 — 134.7 119.7 — Week 18 — — — — 68.7 — 80.7 22.7 45.7 601 Pre-vacc 0.0 0.5 0.0 3.0 0.0 1.3 0.0 0.7 0.0 Week 9 118.0 92.3 88.3 74.3 417.3 — 112.7 102.0 — Week 18 96.0 55.0 — — 133.7 — 52.3 55.7 — 602 Pre-vacc 0.0 0.0 8.5 3.8 0.0 1.0 0.0 3.3 0.0 Week 9 — — — — — — — — — Week 18 — — — — — — — — — 603 Pre-vacc 0.0 0.5 6.0 1.0 0.0 0.7 6.3 0.0 0.3 Week 9 63.0 60.3 114.7 101.0 32.7 — 30.0 26.3 320.0 Week 18 20.7 32.7 — — 8.0 — — 11.3 — 604 Pre-vacc 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0 Week 9 55.3 75.0 70.0 62.3 109.3 — 88.3 66.3 — Week 18 187.0 161.3 413.3 — 397.3 — 314.7 220.0 — 605 Pre-vacc 0.0 3.9 0.0 0.0 5.0 13.7 0.0 0.0 20.3 Week 9 43.7 30.0 — — 65.7 — 32.7 35.0 — Week 18 109.7 129.7 — — — — 33.7 — — 606 Pre-vacc 3.0 1.3 5.2 0.0 2.0 1.2 3.7 5.7 3.7 Week 9 — — — — 24.3 — — — — Week 18 — — — — 45.0 — 71.0 38.3 24.7 607 Pre-vacc 4.2 1.7 2.7 0.0 0.0 0.0 3.3 2.2 0.7 Week 9 196.7 165.7 72.7 30.3 593.3 — 389.3 176.7 172.0 Week 18 586.7 426.7 414.7 372.0 1648.0 — 1642.7 1658.7 1184.0 608 Pre-vacc 8.5 0.0 4.3 0.0 3.7 0.5 0.0 2.0 1.8 Week 9 — — — 6.3 — — — — — Week 18 — — — — 18.0 — — — — 609 Pre-vacc 3.7 4.5 6.2 0.5 0.0 0.0 1.5 2.0 6.8 Week 9 — 28.3 75.3 100.7 89.0 — 58.0 24.7 — Week 18 31.7 29.0 22.0 17.0 86.0 — 14.7 9.3 — Mean Week 9 86.5 75.3 84.2 62.5 178.0 — 120.8 78.7 246.0 SFC Week 18 172.0 139.1 283.3 194.5 300.6 — 315.7 288.0 418.1 No. Positive MAGE3.112I5 p53.139L2B3 p53.149M2 Epitopes Patient Sample A WT A WT A WT Vaccine WT.sup.f) 551 Pre-vacc 10 17 13.5 12.8  0.0 2.7 Week 9 — — — — — — 3 1 Week 18 8.7 7.7 — — — — 4 3 601 Pre-vacc 0.0 1.0 0.3 2.8 0.0 0.0 Week 9 27.0 — 129.0 — — — 6 3 Week 18 — — 96.0 — — — 4 2 602 Pre-vacc 2.0 1.5 0.0 0.0 0.5 1.0 Week 9 — — — — — — 0 0 Week 18 — — 22.7 — — — 1 0 603 Pre-vacc 3.5 1.8 6.0 0.8 1.0 0.0 Week 9 — — 85.3 — — — 6 4 Week 18 16.0 12.3 — — — — 3 3 604 Pre-vacc 0.0 0.0 0.0 0.0 0.2 4.5 Week 9 60.3 43.7 41.0 — — — 6 4 Week 18 268.0 — 188.7 — — — 6 2 605 Pre-vacc 0.0 0.0 1.0 1.8 0.0 9.3 Week 9 — — 9.7 — — — 4 2 Week 18 — — 44.7 — — — 3 1 606 Pre-vacc 0.7 1.7 0.0 0.3 0.0 1.0 Week 9 — — 43.7 — — — 2 0 Week 18 18.7 — 37.7 — — — 5 2 607 Pre-vacc 4.3 0.0 4.2 0.7 1.0 0.0 Week 9 60.3 23.0 114.3 — — — 7 5 Week 18 — — 146.7 — — — 6 4 608 Pre-vacc 2.7 0.0 24.0 2.8 2.0 2.3 Week 9 — — — — 18.0  — 1 1 Week 18 — — — — — — 1 0 609 Pre-vacc 1.7 1.0 35.8 0.0 0.0 4.2 Week 9 — — — — — — 3 3 Week 18 — — — — — — 4 3 Mean Week 9 49.2 33.3 70.5 — 18.0  — SFC Week 18 77.8 10.0 89.4 — — — .sup.a)A, CTL were tested against the vaccine analog. .sup.b)WT, CTL were tested against the vaccine wild type epitope corresponding to the vaccine analog. .sup.c)Value indicates the net pre-vaccination SFC per 50,000 cells tested against the indicated epitope. .sup.d)Value indicates the net SFC per 50,000 cells of vaccine positive responses. .sup.e)—, indicates SFC response did not meet criteria and vaccine response was negative. .sup.f)Total number of vaccine positive response against a vaccine wild type epitope or the wild type epitope corresponding to the vaccine analog.

(23) TABLE-US-00002 TABLE 1B B. Summary of CTL responses in 6 NSCLC patients CEA.24V9 CEA.605D6 CEA.691H5 HER2.369L2V9 MAGE2.157 Patient Sample A.sup.a) WT.sup.b) A WT A WT A WT WT 201 Pre-vacc 0.0.sup.c) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 32.7 Week 9 — —.sup.e) — — — — — — — Week 18 — — — — — — — — — 502 Pre-vacc 0.0 0.0 0.0 9.3 4.2 4.0 4.7 2.2 0.7 Week 9 — — — — — — — — 9.3 Week 18 — — — — — — — — — 504 Pre-vacc 0.0 0.0 3.3 0.3 0.0 0.5 1.7 1.0 1.7 Week 9 — — 20.7 — 42.7 — 84.3 71.0 50.7 Week 18 25.3.sup.d) 23.3  214.3 15.7  284.0 — 284.0 155.7 124.7 505 Pre-vacc 5.2 1.5 8.8 9.7 6.7 11.7  16.7 32.0 7.5 Week 9 — — — — — — — — — Week 18 — — 60.7 33.0  45.3 — 53.0 — — 532 Pre-vacc 0.0 0.0 0.0 0.2 0.0 0.0 0.0 0.0 0.0 Week 9 — — — — 125.7 — — — — Week 18 43.3 — — — — — 78.3 — — 651 Pre-vacc 0.2 0.7 0.0 0.0 1.7 0.2 2.3 1.2 2.0 Week 9 — — — — — — — — — Week 18 — — — — 68.7 — 22.0 — 9.0 Mean Week 9 — — 20.7 — 84.2 — 84.3 71.0 30.0 SFC Week 18 34.3 23.3  137.5 24.3  132.7 — 109.3 155.7 66.8 No. Positive Week 9 0 0   1 0   2 0   1 1 2 Responses Week 18 2 1   2 2   3 0   4 1 2 No. Positive MAGE3.112I5 p53.139L2B3 p53.149M2 Epitopes Patient Sample A WT A WT A WT Vaccine WT.sup.f) 201 Pre-vacc 22.8  51.5  0.0 0.0 16.5  16.5  Week 9 — — — — — — 0 0 Week 18 — — — — — — 0 0 502 Pre-vacc 3.5 2.5 0.0 0.0 5.7 6.2 Week 9 — — — — — — 1 1 Week 18 — — — — — — 0 0 504 Pre-vacc 1.8 0.3 1.3 1.8 1.8 0.8 Week 9 — — 18.7 — — — 5 2 Week 18 — — 90.3 — — — 6 4 505 Pre-vacc 13.3  13.8  0.0 5.8 21.7  12.5  Week 9 — — — — — — 0 0 Week 18 — — 20.3 — — — 4 1 532 Pre-vacc 0.0 7.0 25.2 0.5 2.7 0.0 Week 9 — — 53.0 — — — 2 0 Week 18 — — 117.3 — — — 3 0 651 Pre-vacc 2.7 0.8 0.0 1.0 3.3 2.8 Week 9 — — 6.0 — — — 1 0 Week 18 — — 20.0 — — — 4 1 Mean Week 9 — — 25.9 — — — SFC Week 18 — — 62.0 — — — No. Positive Week 9 0   0   3 0   0   0   Responses Week 18 0   0   4 0   0   0   .sup.a)A, CTL were tested against the vaccine analog. .sup.b)WT, CTL were tested against the vaccine wild type epitope corresponding to the vaccine analog. .sup.c)Value indicates the net pre-vaccination SFC per 50,000 cells tested against the indicated epitope. .sup.d)Value indicates the net SFC per 50,000 cells of vaccine positive responses. .sup.e)—, indicates SFC response did not meet criteria and vaccine response was negative. .sup.f)Total number of vaccine positive response against a vaccine wild type epitope or the wild type epitope corresponding to the vaccine analog.

Example 2

Early T Memory Cell Involvement Confirmed in Phase 2

(24) CTL Immune responses measured though cultured Elispot. The immunogenicity was measured in Phase 2 clinical trial on cryopreserved PBMC from each test sample were thawed in 5% human culture medium (RPMI-1640 medium with 25 mM HEPES, supplemented with 5% human AB serum, 4 mM L-glutamine, 0.5 mM sodium pyruvate, 0.1 mM MEM non-essential amino acids, 100 μg/ml streptomycin, and 100 U/ml penicillin) containing 30 μg/ml DNAase. After centrifugation for 5 minutes at 1200 rpm, the cell pellets were resuspended in 5% human culture medium and washed 2 times. For the central Memory T cell cultured ELISPOT assay, 2×106/ml PBMC were placed in replicate wells in a 48-well plates and stimulated for 10 days with 10 μg/ml of each peptide. As a positive control, PBMC were also stimulated with a pool of recall viral peptides. Human rIL2 (10 U/ml) was added to the peptide-stimulated cultures at day 1, day 4 and day 7. After 10 days the stimulated cells were harvested and plated at a concentration of 5×104/well. Assay wells also received irradiated autologous PBMC (1×105/well) and 10 μg/ml peptide, either the vaccine peptide, irrelevant peptide or positive control peptides. Cells stimulated in vitro with each analog epitope were also tested against the corresponding wild-type epitope.

(25) HTL Immune responses measured though standard Elispot. For the HTL ELISPOT assay measuring T helper responses to the PADRE epitope, 4×106/ml PBMC were placed in a 12 well-plate for overnight culture. Cells were then harvested and placed at 2×105/well in flat-bottom 96-well nitrocellulose plates which had been pre-coated with anti-IFN-γ monoclonal antibody (mAb) (10 μg/ml; clone 1-D1K; Mabtech). Cells plated in 6-well replicates were stimulated with 10 μg/ml PADRE peptide or with an irrelevant malaria SSP2 peptide. After 20 hrs incubation at 37° C., the assay plates were washed with PBS/0.05% Tween-20 and 100 μl/well of biotinylated anti-IFN-γ mAb (2 μg/ml; clone 7-B6-1; Mabtech) was added to wells. The plates were incubated for 2 hrs at 37° C. then washed 6 times. Finally, spots from IFN-γ-secreting cells were developed by sequentially incubating wells with Vectastain ABC and 3-amino-9-ethyl carbazole (AEC) solutions. Spots were counted by a computer-assisted image analysis reader (Zeiss KS ELISPOT Reader).

(26) Data analysis and acceptance criteria. Mean and standard deviation (SD) of spots in replicate wells were calculated in all assays by transferring raw ELISPOT data from each experiment to an Excel-based computer program. Positive vaccine-induced T-cell responses were determined according to the criteria described below.

(27) Acceptance Criteria for peptide-Induced specific T-cell response through central memory T cells: The positive criteria for CTL responses used in the phase 2 trial was identical to the criteria in the phase 1/2 trials which was established prospectively after analyzing the variability of pre-treatment responses in patients against each vaccine epitope and the irrelevant HBV control epitope. A positive peptide-induced CTL/T memory response to a given epitope met all of the following conditions: 1) was greater than 5 SFC above the irrelevant epitope response, 2) was greater than the mean SFC of the irrelevant epitope response, plus 2 SD, and 3) was two-fold greater than the SFC response in the pre-vaccination sample from the same patient, plus 2 SD. The inclusion of “plus two standard deviations” was used to accommodate the assay variability and served to increase the criteria stringency.

(28) The criteria for a positive HTL response to the HTL PADRE epitope, measured without prior expansion of PBMC, were as follows: 1) a PADRE-specific response >5 net SFC per 2×105 cells after subtracting background; 2) for each sample tested in 6-well replicates, a t-test p value<0.05 when comparing SFC from wells stimulated with the irrelevant HLA-DR binding malaria peptide versus wells stimulated with the PADRE peptide; and 3) a t-test p value<0.05 when comparing SFC induced by stimulation with the PADRE peptide in the pre- versus post-vaccination samples. All three criteria had to be fulfilled before a HTL response was considered to be induced by OSE-2101 vaccination.

(29) Results

(30) Patient enrollment and immune monitoring criteria. A total of 64 HLA-A2+ patients with stage IIIB, IV or recurrent NSCLC in the phase 2 trial were treated with at least one dose of OSE-2101. Thirty three patients completed the initial phase of the study consisting of six doses of OSE-2101 administered at 3-week intervals and were monitored for epitopes-induced T-cell/T memory cells responses. Results of tests from this patient cohort are described below with a particular attention on early response at W9 (after 3 injections) and W18 (after 6 injections).

(31) The breadth of CTL/central memory T cell responses induced in each of the 11 first patients and the immunogenicity profile of individual vaccine epitopes was very similar to the phase 1/2 trials in early-stage NSCLC and colon cancer patient with less burden disease.

(32) Most of the CTL effector/central memory T cells responses in treated patients were induced during the initial 3 to 6-dose/18-week treatment phase and surprisingly as early as after 3 weeks (3 doses). Preferably, the CTL/central memory T cell responses induced during this period, including those directed to Wild Type epitopes, have to be maintained by continued boosting with OSE-2101 sub-cutaneous injections at 2-3 month intervals.

(33) For the remaining 22 patients able to have a leukapheresis and an immunogenicity testing, the overall data indicated that immune monitoring of samples against five of the more immunogenically relevant epitopes in the product (CEA.24V9 (SEQ ID No 3), CEA.605D6 (SEQ ID No9), HER2.369V2V9 (SEQ ID No 4), MAGE3.112I5 (SEQ ID No 8) and MAGE2.157 (SEQ ID No 2)) was sufficient for determining T cell and central memory T cell immunogenicity. The clinical timepoints selected for batch testing were the pre-treatment, Week 9, Week 18 and Week 30 timepoints since most CTL/central memory T cells responses observed among the first 11 patients who were tested indicated were already induced by Week 9 and Week 18 and some were maintained at Week 30.

(34) The immunogenicity of OSE 2101 was similar in phase 2 advanced patients (NSCLC HLA A2 positive patients in advanced stage invasive or metastatic and after at least first line therapy failure) to that observed previously in the two phase 1/2 trials in terms of the overall breadth of CTL+/central memory T cells responses induced in patients and the level of immunogenicity of individual epitopes, thus confirming the overall potency of the product in different patient populations. Multi-epitope CTL+/central memory T cells responses, defined by responses to at least 3 of 5 representative immunogenic epitopes in the OSE-2101 treatment, were observed in 22 of the 33 patients (67%) who were monitored in the phase 2 trial and were achieved as early as Week 9.

(35) TABLE-US-00003 TABLE 2 week 9 week 18 week 30 month 9 month 12 Antigen Epitope % % % % % CEA CEA24-ANA 13/33 39% 10/32 31%  9/23 28% 4/7 57% 2/4 50% CEA24-WT 12/33 36%  7/32 22%  5/23 22% 2/7 29% 1/4  0% CEA605-ANA  9/33 27% 10/32 31%  8/23 35% 1/7 14% 1/4 25% CEA605-WT 10/33 30%  5/32 16%  8/23 35% 1/7 14% 0/4  0% CEA691-ANA  7/11 64% 10/11 91% 2/6 33% 3/7 43% 2/4 50% CEA691-WT  0/11  0%  0/11  0% 0/6  0% 0/7  0% 0/4  0% HER2 HER2.369-ANA 14/33 42% 14/32 44% 13/23 57% 2/7 29% 2/4 50% HER2.369-WT 11/33 33%  9/32 28% 10/23 43% 2/7 29% 2/4 50% HER2-689-WT  4/11 36%  3/11 27% 0/6  0% 0/7  0% 0/4  0% MAGE MAGE2.157-WT  9/33 27%  9/32 28% 10/23 43% 4/7 57% 2/4 50% MAGE3.112-ANA 10/33 30%  8/32 25% 10/23 43% 0/7  0% 0/4  0% MAGE3.112-WT 10/33 30%  3/32  9%  5/23 22% 0/7  0% 0/4  0% p53 p53.139-ANA  6/11 55%  4/11 36% 3/6 50% 2/7 29% 2/4 50% p53.139-WT  2/11 18%  1/11  9% 0/6  0% 0/7  0% 0/4  0% p53.149-ANA  1/11  9%  0/11  0% 0/6  0% 0/7  0% 0/4  0% p53.149-WT  0/11  0%  1/11  9% 0/6  0% 0/7  0% 0/4  0% ANA = Analog peptide, WT = Wild-type peptide

(36) The first 11 patients were tested with all 9 peptide epitopes and the remaining 22 patients were tested with 5 shaded peptide epitopes (CEA24 (SEQ ID No 3), CEA605 (SEQ ID No 9), HER2.369 (SEQ ID No 4), MAGE2.157 (SEQ ID No 2) and MAGE3.112 (SEQ ID No8)). Results are also shown in FIG. 2.

(37) The early W9 response was at the same level as the W18 response and the long term response was still present at one year for patients able to receive a leukapheresis. The long term response was maintained though additive injections.

(38) HTL responses were measured from PBMCs without an in vitro expansion step by standard Elispot. PBMCs were thawed, rested overnight in medium, and 2*10.sup.5 PBMCs/well were stimulated with 10 μg/mL Pan DR epitope (HTL) or irrelevant malaria peptide in the interferon gamma ELISPOT assay.

(39) IFN-γ producing helper T-cells against PADRE were detected in 18 of 33 patients tested (55%), without short-term in vitro expansion of PBMCs with peptide and was in the same range at Week 9 or Week 18 demonstrating an early HTL response to the epitopes combination.

(40) Then, a correlation between OSE-2101-induced PADRE HTL responses and CTL/central memory T cell responses exists (FIG. 3). The correlation coefficient for this analysis is 0.405.

Example 3

Impact on Time-to-Progression (TTP) Though Early T memory Cells Involvement

(41) TTP results of the short peptide combination in advanced NSCLC after at least first line failure (OSE 2101 phase 2 data internal report). Clinically in oncology, the presence of high levels of infiltrating memory T cells, evaluated immunohistochemically, correlated with the absence of signs of early metastatic invasion, a less advanced pathological stage, and increased survival in 959 specimens of resected colorectal cancer (Pages, F et al, 2005, N Engl J Med; 353:2654-2666). The TTP is interesting as a coherent surrogate item correlated with effector memory T cells for long term and disease free survival.

(42) Sixty-three (63) patients who were HLA-A2 and received OSE-2101 were included in the Time-to-Progression (TTP) analysis. Twenty-eight (28) patients had documented disease progression. Using the Kaplan-Meier estimator, the median time to progression was determined to be 285 days.

(43) The median of the Time to progression (TTP median) after short peptides combination OSE-2101 was 285 days or 9.4 months (SD 86 days). This important clinical item is related to the effector memory CD8+cytotoxic T cells early stimulation (TTP is defined as the time from randomization until objective tumor progression; TTP does not include deaths. PFS is defined as the time from randomization until objective tumor progression or death).

(44) In the same type of advanced NSCLC population (invasive or metastatic) and after at least first line failure (second line treatment), the Progression-Free Survival (PFS) was described at 2.2 months with a Tyrosine kinase inhibitor as Erlotinib (Shepherd F A, et al., 2005, N Engl J Med.; 353, 123-132).

(45) Two chemotherapeutic agents, docetaxel and pemetrexed, and erlotinib are currently approved for the second line treatment of NSCLC patients. The observed TTP in the two clinical phase 3 for docetaxel was between 10.6 and 26 weeks. From pemetrexed phase 3 results, the median PFS was 2.9 months (M A Bareschino; J Thorac Dis 2011; 3:122-133). The median PFS was 3.5 months in the nivolumab phase 3 study in squamous NSCLC (Julie Brahmer, et al, 2015, New England Journal of Medicine May 31).

(46) The unexpected early results of CTL induction through central memory T cell induction by short epitope sequences from tumor antigens of OSE-2101 vaccine, establish the clinical utility of epitopes combination as T specific immunotherapy against cancer and is of particular interest for short term T memory immune responses providing long term efficacy in poor prognosis cancer patients.

Example 4

Results on Advanced Cancer Patients with Malignant Pleural Effusion (MPE)

(47) Patients present an MPE as a complication of far-advanced cancer or as the initial manifestation of an underlying malignancy. Common cancer types causing MPEs include lymphomas, mesotheliomas, and carcinomas of the breast, lung, gastrointestinal tract, and ovaries. The annual incidence of malignant pleural effusions in the United States is estimated to be greater than 150,000 cases. Survival curves for more than 8,000 patients with nonsmall-cell lung cancer (NSCLC) with pleural effusion (i.e., stage IIIB) from the SEER database showed that long-term survival is uncommon in this group. The median survival time is approximately 3 months. Pleural effusion restricts ventilation and causes progressive shortness of breath by compression of lung tissue as well as paradoxical movement of the inverted diaphragm. Pleural deposits of tumor cause pleuritic pain.

(48) Pleural effusions occur more commonly in patients with advanced-stage tumors, who frequently have metastases to the brain, bone, and other organs; physiologic deficits; malnutrition; debilitation; and other comorbidities. Because of these numerous clinical and pathologic variables, it is difficult to perform prospective trials in patients with pleural effusions. For the same reason, it is often difficult to predict a potential treatment outcome or anticipated duration of survival for the specific patient with multiple interrelated clinical problems. Pleural effusion was the first symptom of cancer in 41% of 209 patients with malignant pleural effusion; lung cancer in men (42%) and ovarian cancer in women (27%) were most common.

(49) The discovery of malignant cells in pleural fluid and/or parietal pleura signifies disseminated or advanced disease and a reduced life expectancy in patients with cancer.

(50) In order to understand the role of central memory T cells discovered in phase 2 Cancer patients, the inventors have analyzed retrospectively a sub group of patients presenting Malignant Pleural Effusion. The study was designed to evaluate the safety, efficacy (response and survival), and immunogenicity of OSE-2101 in patients with advanced NSCLC (stage IIIb and IV) who were HLA-A2 positive. The multi-epitope combination was administered subcutaneously at a dose of 5 mg every 3 weeks for the first 15 weeks, then every 2 months through year 1, then quarterly through year 2.

(51) A subgroup of 5 patients was presenting pleural effusion, 2 patients were NSCLC stage IIIB and 3 patients were NSCLC stage IV metastatic.

(52) According to the literature, patients with Malignant Pleural effusions (MPEs) present a severe prognosis with intrathoracic and extrathoracic malignancies. Median survival after diagnosis of an MPE is between 3-4 months. These patients were supposed to have the worse survival time and were thus supposed to be the first to die, shortly in the study.

(53) These 5 patients with MPE were achieving, after receiving the OSE-2101 T specific immunotherapy, a long time without progression and also a very long term survival.

(54) TABLE-US-00004 TABLE 4A MPE on NSCLC Patients description Patient Number 166 (site 115) 104 (site121) 172 (site 116) 144 (site 217) 170 (site 217) NSCLC NSCLC NSCLC NSCLC NSCLC gender female female male male Female age 58 Y 73 Y 88 Y 55 Y 45 Y Ethnic Asian Caucasian Caucasian Caucasian African origin American NSCLC IIIB IIIB IV IV IV Stage MPE pleural effusion Pleural Pleural effusion Pleural effusion Pleural effusion plus pericardial effusion effusion Previous pericardiocentesis Thoracentesis Chest Chest RXth Thoracentesis treatments Chest Chest RXth Radiotherapy (5040 CY) and 3 lines of Radiotherapy (70.2 CGY) (5940 GY) and 4 lines Carboplatin + (10300 cGY) and 1 line of and 1 line of of paclitaxel + and 1 line of chemotherapy chemotherapy chemotherapy gemzar chemotherapy Carboplatin + cisplatin + VP16 Carboplatine + TRM 1 carboplatin + paclitaxel paclitaxel investigational paclitaxel Tarceva drug; Topotecan Tarceva Alimta

(55) TABLE-US-00005 TABLE 4B Time to progression - Survival OS - number of injections Patient Number 166 121 172 144 170 NSCLC NSCLC NSCLC NSCLC NSCLC OS 20 months 19 months 18 months 6 months 26 months Time to Stable Disease 19 months  6 months 5 months  3 months progression lost of follow up at 20 months CTL + CTL+/central CTL+/central CTL+/central Not done Not done central memory T versus memory T memory T Memory T 4 epitopes Versus 4 versus 4 cell epitopes epitopes responses Number of 3 + 9 3 + 7 3 + 6 3 + 2 3 injections

(56) The time to progression achieved in such poor prognosis MPE population is impressive with a median over than 6 months (3 to 20 months). The median survival achieved is 18 months (6 to 26 months). These long term clinical results are related to an initial priming of 3 injections though the early involvement of central memory T Cells recruiting effector cells CD8.sup.+ T cells. In addition, 3 patients/5 are presenting strong positive responses versus 4 epitopes.