Associations among cytokines, EGF and lymphocyte subpopulations in patients diagnosed with advanced lung cancer

Aging is considered the single most significant risk factor for the majority of common malignances including lung cancer. Together immunosenescence, changes occurring with aging in the immune system, and inflammaging, characterizes by a chronic, subclinical accumulation of pro-inflammatory factors, are suggested to stand at the origin of most of the diseases of the elderly, such as cancer. The aim of this study was to determine associations among lymphocyte subpopulations, pro-inflammatory cytokines and epidermal growth factor (EGF) in patients diagnosed with non-small cell lung cancer (NSCLC). Forty-six advanced NSCLC patients were enrolled. Sixteen patients with newly diagnosed and before treatment and 30 patients after first-line platinum-based chemotherapy. Peripheral blood subpopulations were studied by flow cytometry and serum concentrations of soluble factors by ELISA. The frequency of naïve CD4⁺ T cells, naïve B cells and central memory CD8⁺ T cells were significantly lower in NSCLC patients after chemotherapy, while effector memory CD4⁺ T cells and terminally differentiated CD8⁺ T cells were significantly higher. IL-1β and TNFα significantly correlated among them before and after platinum-based chemotherapy. Terminally differentiated T cells expressing CD57⁺ significantly correlated with TNFα and IL-1β. For the first time, associations between EGF serum levels and terminally differentiated CD4⁺ T cells, and memory B cells were detected. This study confirms the association among terminally differentiated lymphocytes and pro-inflammatory cytokines in patients diagnosed with lung cancer, reinforcing the interconnection between terminally differentiated lymphocytes and pro-inflammatory cytokines. Clinical trial registration number: RPCEC00000205, http://registroclinico.sld.cu/.

Anti-EGF antibodies as surrogate biomarkers of clinical efficacy in stage IIIB/IV non-small-cell lung cancer patients treated with an optimized CIMAvax-EGF vaccination schedule

We previously reported that CIMAvax-EGF vaccine is safe, immunogenic and efficacious to treat advanced non-small-cell lung cancer (NSCLC) patients. A phase III trial was designed using an optimized immunization schedule. It included higher antigen dose and injections at multiple sites. Immune response and circulating biomarkers were studied in a subset of patients. EGF-specific antibody titers, IgG subclasses, peptide immunodominance and circulating biomarkers were assessed by ELISA. In vitro EGF-neutralization capacity of immune sera and EGF-IgG binding kinetics was evaluated by Western Blot and Surface Plasmon Resonance (SPR) technology, respectively. We show that CIMAvax-EGF elicited mainly IgG3/IgG4 antibodies at titers exceeding 1:4000 in 80% of vaccinated patients after 3 months of treatment. The EGF-specific humoral response was directed against the central region of the EGF molecule. For the first time, the kinetic constants of EGF-specific antibodies were measured evidencing affinity maturation of antibody repertoire up to month 12 of vaccination. Notably, the capacity of post-immune sera to inhibit EGFR phosphorylation significantly increased during the course of the immunization scheme and was related to clinical outcome (P = .013, log-rank test). Basal concentrations of EGF and TGFα in the serum were affected by EGF-based immunization. In conclusion, the CIMAvax-EGF vaccine induces an EGF-specific protective humoral response in a high percent of NSCLC vaccinated patients, the quantity and quality of which were associated with clinical benefit (clinical trial registration number: RPCEC00000161, http://registroclinico.sld.cu/).

Abbreviations

EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; Ab: antibody; AR: amphiregulin; NSCLC: non-small-cell lung cancer; rhEGF: recombinant human epidermal growth factor; BSC: best supportive care; TGFα: tumor growth factor alpha; IL-8: interleukin 8; MAb: monoclonal antibody; SPR: surface plasmon resonance

Differential effects of two therapeutic cancer vaccines on short- and long-term survival populations among patients with advanced lung cancer

BACKGROUND

Progress in immunotherapy has revolutionized the treatment landscape for advanced lung cancer, with emerging evidence of patients experiencing long-term survivals. The goal of this study was to explore the existence of short- and long-term survival populations and to assess the effect of immunotherapy on them.

METHODS

Data from two randomized, multicenter, controlled clinical trials was used to evaluate the effect of two therapeutic vaccines (anti-idiotypic vaccine VAXIRA and anti-EGF vaccine CIMAVAX) on survival curves in advanced non-small cell lung cancer patients. Data were fitted to Kaplan-Meier, standard Weibull survival, and two-component Weibull mixture models. Bayesian Information Criterion was used for model selection.

RESULTS

VAXIRA did not modify, neither the fraction of patients with long-term survivals (0.18 in the control group v 0.19 with VAXIRA, P = .88), nor the median overall survival of the patients in the short-term survival subpopulation (6.8 v 7.8 months, P = .24). However, this vaccine showed great benefit for the patients belonging to the subpopulation of patients with long-term survival (33.8 v 76.6 months, P <.0001). CIMAVAX showed impact in the overall survival of both short- and long-term populations (6.8 v 8.8 months, P = .005 and 33.8 v 61.8 months, P = .007). It also increased the proportion of patients with long-term survival (from 0.18 to 0.28, P = .02).

CONCLUSIONS

This study shows that therapeutic vaccines produce differential effects on short- and long-term survival populations and illustrates the application of advanced statistical methods to deal with the long-term evolution of patients with advanced lung cancer in the era of immunotherapy.

CIMAvax-EGF: Toward long-term survival of advanced NSCLC

Lung cancer remains one of the leading causes of cancer-related deaths. Non-small cell lung cancer (NSCLC) is the most common histologic type of lung cancer. Medical and scientific progress has led to longer survival in an increasing number of patients suffering from cancer. Concerning patients with advanced NSCLC, there is a subgroup with long-term survival. The human epidermal growth factor receptor (EGFR) family plays a key role in tumor development. This cluster of genes is associated with augmented angiogenesis and enhanced proliferation, survival, and migration of tumor cells. The CIMAvax-EGF vaccine consists of a chemical conjugate of the EGF with the P64 protein derived from the Meningitis B bacteria and the Montanide ISA 51, as adjuvant. The vaccine induces antibodies against EGF that results in EGF withdrawal. CIMAvax-EGF has been demonstrated to be safe and immunogenic in advanced NSCLC patients. Here we summarize the current knowledge of the mechanism of action of CIMAvax-EGF, highlighting the impact of this anti-EGF-based vaccine on the long-term survival of advanced NSCLC patients.

A Phase III Clinical Trial of the Epidermal Growth Factor Vaccine CIMAvax-EGF as Switch Maintenance Therapy in Advanced Non-Small Cell Lung Cancer Patients

PURPOSE

EGFR is a well-validated target for patients with non-small cell lung cancer (NSCLC). CIMAvax-EGF is a therapeutic cancer vaccine composed of human recombinant EGF conjugated to a carrier protein and Montanide ISA51 as adjuvant. The vaccine is intended to induce antibodies against self EGFs that block EGF-EGFR interaction.

EXPERIMENTAL DESIGN

To evaluate overall survival, safety, immunogenicity, and EGF concentration in serum after CIMAvax-EGF, a randomized phase III trial was done in patients with advanced NSCLC. Four to 6 weeks after first-line chemotherapy, 405 patients with stage IIIB/IV NSCLC were randomly assigned to a vaccine group, which received CIMAvax-EGF or a control group, treated with best supportive care.

RESULTS

Long-term vaccination was very safe. Most frequent adverse reactions were grade 1 or 2 injection-site pain, fever, vomiting, and headache. Vaccination induced anti-EGF antibodies and decreased serum EGF concentration. In the safety population, median survival time (MST) was 10.83 months in the vaccine arm versus 8.86 months in the control arm. These differences were not significant according the standard log rank (HR, 0.82; P = 0.100), but according a weighted log rank (P = 0.04) that was applied once the nonproportionality of the HR was verified. Survival benefit was significant (HR, 0.77; P = 0.036) in the per-protocol setting (patients receiving at least four vaccine doses): MST was 12.43 months for the vaccine arm versus 9.43 months for the control arm. MST was higher (14.66 months) for vaccinated patients with high EGF concentration at baseline.

CONCLUSIONS

Switch maintenance with CIMAvax-EGF was well tolerated and significantly increased MST of patients that completed induction vaccination. Baseline EGF concentration predicted survival benefit. Clin Cancer Res; 22(15); 3782-90. ©2016 AACR.

Biomarkers related to immunosenescence: relationships with therapy and survival in lung cancer patients

PURPOSE

There are well-known alterations occurring within the immune system with aging. Collectively, these changes are known as immunosenescence. The incidence of malignancies also increases with age. The aim of this study was to determine the presence of immunosenescence biomarkers in non-small cell lung cancer (NSCLC) patients and to evaluate some of them as predictive biomarkers of CIMAvax-EGF cancer vaccine efficacy.

METHODS

Sixty-six NSCLC patients, vaccinated or not with CIMAvax-EGF cancer vaccine, and 37 age-matched controls were enrolled. Peripheral blood samples were studied for CD19+, CD4+, CD8+, CD28-, CD57+ and CD45RA+ subpopulations by flow cytometry.

RESULTS

Absolute count of CD19+ and the CD4/CD8 ratio were significantly lower in NSCLC patients than in age-paired controls, while highly differentiated T cells increased in NSCLC patients treated with platinum-based chemotherapy. Using Cox regression, we were able to dichotomize the patient population according to biomarkers. Vaccinated patients with frequency <24 % of CD8 + CD28- T cells, >40 % of CD4 T cells and CD4/CD8 ratio higher than two at the beginning of immunotherapy achieved a 20-month increase in median survival regarding control patients.

CONCLUSIONS

Distribution of lymphocyte subsets was influenced by cancer and chemotherapy in NSCLC patients. CD19 + B cells decrease by cancer disease and not by chemotherapy, and CD28- subpopulations increase by chemotherapy and not by cancer. The proportion of CD8 + CD28- T cells, CD4+ T cells and CD4/CD8 ratio can be used as predictive biomarkers of CIMAvax-EGF efficacy in NSCLC patients and thereby could, be a useful tool for a personalized treatment.

Therapeutic Vaccination with Epidermal Growth Factor (EGF) in Advanced Lung Cancer: Analysis of Pooled Data from Three Clinical Trials

We have undertaken the analysis of pooled data from three pilot clinical trials of vaccination with Epidermal Growth Factor (EGF) in patients with advanced non small cell lung cancer (NSCLC), addressing particularly the issue of the relationship between immunization and survival. Eighty-three patients with advanced disease were included in three pilot clinical trials and vaccinated with the EGF Vaccine. The trials were designed to evaluate the immunogenicity and safety of the vaccine using different adjuvants, cyclophosphamide pretreatment or not, and different dosage levels of the vaccine. The vaccine elicited specific anti-EGF antibody titers in 83% of subjects, and 49% developed a good anti-EGF antibody response. The adjuvant, the vaccine dose, and cyclophosphamide pretreatment significantly influenced immunogenicity. Patients that seroconverted survived significantly longer than patients who did not. Good antibody responders survived significantly longer than poor responders. Pooled results from these trials confirm that vaccination with EGF is safe and immunogenic in advanced NSCLC patients. The association between good antibody responses and survival consistently appeared in every single trial independently of the specific trial designs. Although these were small pilot nonrandomized clinical trials not intended to confirm therapeutic effect, the survival of the pooled patient population was statistically greater compared with 163 control patients receiving standard treatment.

Active immunotherapy in patients with progressive disease (PD) after first-line therapy: Racotumomab experience

3086

Background: Racotumomab is a therapeutic vaccine that induces a cellular and humoral immune response against NeuGc-containing gangliosides expressed in several tumors but not in normal human tissues. A previous randomized, double blinded, placebo-controlled trial has demonstrated low toxicity of racotumomab and a statistically significant benefit in overall survival (OS) in patients with advanced non-small-cell lung cancer (NSCLC) who had achieved partial or complete response or disease stabilization after first line therapy. Methods: An open, non-randomized study was performed to evaluate if racotumomab could also be beneficial in patients with progressive disease. Patients with recurrent and advanced stages (IIIB/IV) of NSCLC, in progression after completion of first-line onco-specific treatment as per the NCCN Oncology Therapeutic Guidelines (surgery, chemotherapy and/or radiotherapy) were included in the study. Most of them had received 4 to 6 cycles of cisplatin/vinblastin. Vaccination consisted of 5 intradermic doses of racotumomab (1 every 14 days), followed by 1 dose every 28 days until patient refusal or worsening of ECOG status. The patients did not receive second-line therapy. Results: 180 patients were included in an intent to treat (ITT) survival analysis (Kaplan Meier estimate), after at least 10 months of follow-up. Median survival was 8.06 months. OS rate (%) at 24 months was 21%. A control group of 85 consecutive patients treated at the same institution by the same investigators, who did not receive second-line therapy or racotumomab showed a median survival of 6.26 months (log rank test p= 0.011). OS rate (%) at 24 months was only 7%. A per protocol survival analysis including only the 124 patients (68.8%) who received ≥ 5 doses of racotumomab showed a median survival of 12 months. OS rate (%) at 24 months was 30%. Conclusions: Patients with PD after first-line treatment show favorable results in survival when vaccinated with racotumomab. This result is similar to previous clinical trials where racotumomab was administered to patients with objective response (partial or complete) or stable disease after first line therapy.

EGF-based cancer vaccine: Optimizing predictive and surrogate biomarkers

3013

Background: EGFR is overexpressed in many epithelial tumors. EGF is one of the most important growth factors that stimulates EGFR, in a paracrine way. CIMAvax-EGF is a therapeutic cancer vaccine intended to induce antibodies against EGF. It is composed by recombinant EGF conjugated to P64 from N.Meningitides as a carrier and Montanide, as adjuvant. Methods: Two controlled trials were done in advanced NSCLC and castration-resistant prostate cancer patients (CRPC). A multicentric, randomized Phase III trial was designed to assess the efficacy, immunogenicity, and safety of CIMAVAx-EGF in advanced NSCLC patients. Patients with histology- or cytology-proven NSCLC at stage IIIB/ IV were enrolled. All subjects received 4 platinum-based cycles before entering the study. On the other hand, a multicentric, randomized Phase II trial was designed to assess the immunogenicity and safety of the vaccine in CRPC patients. The EGF cancer vaccine was administered in combination with mitoxantrone and prednisone. Results: 405 patients bearing NSCLC and 200 men with CRPC were enrolled in the 2 trials. In both studies the vaccine was immunogenic. Antibody titers against EGF increased with vaccination and EGF concentration in sera showed a fast reduction after immunization. The anti-EGF antibody response was directly correlated with overall survival. CIMAVax-EGF was safe and most prevalent adverse events were grade 1-2 injection site pain, fever, headache, nausea, vomiting, and chills. The vaccine significantly increased the survival of the NSCLC patients while it did not augment significantly the overall survival of the CRPC patients. In both studies, EGF concentration was measured at baseline and it was found to be much higher than in normal subjects. High EGF concentration predicted greater benefit after vaccination. On the contrary, NSCLC and prostate control patients with high levels of EGF had a poorer outcome. Conclusions: Antibody response against EGF is a surrogate marker of survival. High EGF concentration might be a predictive marker of vaccine efficacy and a poor prognostic biomarker for non-vaccinated NSCLC and CRPC patients. The predictive and prognostic value of the EGF concentration will be validated prospectively. Clinical trial information: IIC EC 081.

EGF-based cancer vaccine for advanced NSCLC: Results from a phase III trial

2527

Background: The prognosis of patients with advanced non small cell lung cancer (NSCLC) remains dismal. Epidermal Growth Factor Receptor (EGFR) is overexpressed in epithelial tumors and its role in the development of NSCLC is widely proven. The EGF vaccine is a therapeutic cancer vaccine composed by recombinant Epidermal Growth Factor (EGF) conjugated to a carrier protein, P64K from Neisseria Meningitides and Montanide, as adjuvant. The vaccine is intended to induce antibodies against self EGF that would block EGF-EGFR interaction. Methods: A multicentric, randomized Phase III trial was designed to assess the efficacy, immunogenicity and safety of the EGF cancer vaccine in advanced NSCLC patients. Patients older than 18 years with histology or cytology proven NSCLC at stage IIIB and IV were enrolled in the trial. All patients received no less than 4 platinum-based cycles and achieved at least stable disease, before entering the trial. A low-dose of cyclophosphamide was administered 3 days before the first immunization. Then, patients received 4 quarterly immunizations followed by monthly re-immunizations. Control patients received best supportive care. Results: In total, 405 patients bearing stage IIIB/IV NSCLC were recruited in 21 sites. The vaccine was very well tolerated. The most frequent adverse events consisted in grade 1/2 injection site pain, fever, headache, vomiting and chills. The vaccine was immunogenic. Antibody titers against EGF significantly increased with vaccination and on the contrary, EGF concentration in sera showed a fast reduction after immunization. There was an inverse correlation between the anti-EGF antibody titers and the EGF concentration in sera. Baseline EGF concentration was a worse prognostic factor for the control patients and a predictive factor for vaccinated subjects. The overall survival was significantly better for vaccinated patients as compared to controls. There was a direct correlation between the antibody titers and survival. Conclusions: The EGF cancer vaccine was very well tolerated and significantly increased overall survival of the vaccinated patients. Baseline EGF concentration predicted survival benefit. The EGF vaccine is a new therapeutic option for advanced NSCLC patients.

Response to epidermal growth factor vaccine in patients with metastatic non-small cell lung cancer (NSCLC) after progressing to first-line therapy

2531

Background: A direct correlation between anti–epidermal growth factor (EGF)antibody titers and survival was demonstrated in vaccinated patients with novel NSCLC advanced in Phase II studies. We show the results of treatment with anti-EGF vaccine in a cohort of patients with metastatic NSCLC after progressing to first line therapy. We evaluated immunogenicity, safety, treatment response and effect on survival. Methods: 12 patients with metastatic NSCLC after progressing to first-line therapy received anti EGF-vaccine alone or in combination with chemotherapy. Results: From October 2009 until August 2011, 12 patients started treatment with anti EGF vaccine; mean age 56.5 (42-79 y); 66.7% male; ECOG 0 and 1: 41.7% and 58,3% respectively. Adenocarcinoma (50%), bronchioloalveolar (33.3%), adenosquamous (16.7%). Metastatic sites: lung (41.7%), pleura (25%), CNS (16.7%), Kidney (8.3%). In addition to chemotherapy previous used: radiotherapy (50%), surgery (41.7%), erlotinib (41.7%), bevacizumab (25%). The 50% patients received vaccine alone. The 83.3% of patients had titers 1/4000 sera dilutions or more (good responders). According to RECIST 1.1: CR: 8.3%, PR: 16.7%, SD: 41.7%, PD 25%. Median overall survival was 18.8 months (95% CI: 13.3- 24.4 m). Median progression-free survival was 7.3 months (95% CI: 6.4 -8.2 m). We found no statistically significant differences in OS and PFS when comparing vaccine alone or combined (p = 0.181 and p = 0.801). 75% of patients had adverse effect: more frequently were: 42.4% application site pain, 15.1% fever and 10.38% chills, none of them serious. Conclusions: Vaccination anti EGF in patients with metastatic NSCLC after progressing to first line, alone or in combination, was safe and provoked an increase in anti-EGF antibody titers, produced clinical benefit, improved overall survival and progression free survival.

Safety, immunogenicity and preliminary efficacy of multiple-site vaccination with an Epidermal Growth Factor (EGF) based cancer vaccine in advanced non small cell lung cancer (NSCLC) patients

The prognosis of patients with advanced non small cell lung (NSCLC) cancer remains dismal. Epidermal Growth Factor Receptor is over-expressed in many epithelial derived tumors and its role in the development and progression of NSCLC is widely documented. CimaVax-EGF is a therapeutic cancer vaccine composed by human recombinant Epidermal Growth Factor (EGF) conjugated to a carrier protein, P64K from Neisseria Meningitides. The vaccine is intended to induce antibodies against self EGF that would block EGF-EGFR interaction. CimaVax-EGF has been evaluated so far in more than 1000 advanced NSCLC patients, as second line therapy. Two separate studies were compared to assess the impact of high dose vaccination at multiple anatomic sites in terms of immunogenicity, safety and preliminary efficacy in stage IIIb/IV NSCLC patients. In both clinical trials, patients started vaccination 1 month after finishing first line chemotherapy. Vaccination at 4 sites with 2.4 mg of EGF (high dose) was very safe. The most frequent adverse events were grade 1 or 2 injection site reactions, fever, headache and vomiting. Patients had a trend toward higher antibody response. The percent of very good responders significantly augmented and there was a faster decrease of circulating EGF. All vaccinated patients and those classified as good responders immunized with high dose at 4 sites, had a large tendency to improved survival.

Effective inhibition of the epidermal growth factor/epidermal growth factor receptor binding by anti-epidermal growth factor antibodies is related to better survival in advanced non-small-cell lung cancer patients treated with the epidermal growth factor cancer vaccine

PURPOSE

Epidermal growth factor (EGF) might be a suitable immunotherapeutic target in non-small-cell lung cancer (NSCLC). Our approach consists of active immunotherapy with EGF. The aim of the study is to characterize the humoral response and its effects on signal transduction in relation with the clinical outcome.

EXPERIMENTAL DESIGN

Eighty NSCLC patients treated with first-line chemotherapy were randomized to receive the EGF vaccine or supportive care. EGF concentration in sera, anti-EGF antibodies and their capacity to inhibit the binding between EGF/EGF receptor (EGFR), and the EGFR phosphorylation were measured.

RESULTS

Seventy-three percent of vaccinated patients developed a good antibody response, whereas none of the controls did. In good antibody-responder patients, self EGF in sera was significantly reduced. In 58% of vaccinated patients, the post-immune sera inhibited EGF/EGFR binding; in the control group, no inhibition occurred. Post-immune sera inhibited the EGFR phosphorylation whereas sera from control patients did not have this capacity. Good antibody-responder patients younger than 60 years had a significantly better survival. A high correlation between anti-EGF antibody titers, EGFR phosphorylation inhibition, and EGF/EGFR binding inhibition was found. There was a significantly better survival for vaccinated patients that showed the higher capacity to inhibit EGF/EGFR binding and for those who showed an immunodominance by the central region of EGF molecule.

CONCLUSIONS

Immunization with the EGF vaccine induced neutralizing anti-EGF antibodies capable of inhibiting EGFR phosphorylation. There was a significant positive correlation between antibody titers, EGF/EGFR binding inhibition, immunodominance of anti-EGF antibodies, and survival in advanced NSCLC patients.

Active immunotherapy with 1E10 anti-idiotype vaccine in patients with small cell lung cancer: report of a phase I trial

1E10 is an anti-idiotype murine monoclonal antibody (Ab2 MAb) specific to an Ab1 MAb which reacts with NeuGc-containing gangliosides, sulfatides and with antigens expressed in some human tumors. Preparations containing this Ab2 were capable to induce a strong anti-metastatic effect in tumor-bearing mice. We conducted a Phase I clinical trial to evaluate the toxicity and humoral immune response elicited by 1E10 vaccine in patients with small cell lung cancer (SCLC). Eligible patients were those who after received chemotherapy and/or radiotherapy had partial or complete response to treatment. Patients received four biweekly injections with 2 mg of aluminum hydroxide-precipitated 1E10 MAb, then other six doses at 28-day intervals, and later the patients who maintained a good performance status were reimmunized. Six patients with limited-stage disease and three with extensive-stage disease were enrolled in the study. Most of the patients who received at least four doses of 1E10 vaccine developed strong specific antibody responses against 1E10 MAb and NeuGc-GM3 ganglioside. Antibodies able to react with lung carcinoma tissue sections were detected in sera from vaccinated patients. A prolonged survival was observed in several patients treated with the anti-idiotype vaccine. No evidence of serious adverse effects was found.

Phase I/II clinical trial of the humanized anti-EGF-r monoclonal antibody h-R3 labelled with 99mTc in patients with tumour of epithelial origin

AIM

To evaluate the biodistribution, internal radiation dosimetry and toxicity of the humanized MAb h-R3 labelled with Tc in humans.

METHODS

Twenty-five patients with suspected epithelial-derived tumours were included in this study and divided into two groups: group I consisted of 10 patients who received 3 mg/1110 MBq (3 mg/30 mCi); and group II consisted of 15 patients who received 6 mg/2220 MBq (6 mg/60 mCi). Single photon emission computed tomography (SPECT) and planar images, and multiple blood and urine samples were collected up to 24 h after injection. Haematological parameters and adverse effects were classified according to the WHO criteria. Biodistribution, human anti-mouse antibody (HAMA) response and absorbed doses were estimated and reported.

RESULTS

Liver, spleen, kidneys and heart were identified as source organs. Their higher uptakes were 53.3+/-6.4%ID, 2.0+/-1.4%ID, 9.8+/-4.3%ID and 2.8+/-0.9%ID, respectively. The urinary bladder and large intestine also had a significant uptake. The mean urinary excretion was around 22%ID. The liver received the highest absorbed doses followed by the kidneys and the urinary bladder wall. There were no haematological or biochemical abnormalities with clinical significance related to the product. No patient developed HAMA response. Preliminary analysis of clinical results showed a sensitivity of 76.5% and a specificity of 100%.

CONCLUSIONS

The results of this study suggest that Tc-h-R3 could be used in patients in a safe and effective way, for the diagnosis of epithelial-derived tumours at the two evaluated dose levels.

Epidermal growth factor-based cancer vaccine for non-small-cell lung cancer therapy

BACKGROUND

The role that growth factors and their receptors play in human cancer growth and progression makes them interesting targets for novel treatment modalities. Our approach consisted of active immunotherapy with the epidermal growth factor (EGF). Two pilot clinical trials were conducted to examine the safety and immunogenicity of a five-dose immunization protocol and to compare different adjuvants and treatment designs.

PATIENTS AND METHODS

Forty patients with advanced non-small-cell lung cancer were enrolled in both trials. They were randomized to be treated with aluminum hydroxide or montanide ISA 51 as adjuvants in the EGF vaccine preparation. The use of cyclophosphamide prevaccination treatment was evaluated in the second trial.

RESULTS

Pooled data from both trials showed that the use of montanide as adjuvant increased the percentage of good antibody responders (GAR). Cyclophosphamide prevaccination treatment did not provoke improvements in antibody response. GAR had a significant increase in survival as compared with poor antibody responders. Response duration was also related to a significant improvement in survival rates.

CONCLUSIONS

Vaccination with five doses of EGF vaccine is safe and immunogenic. Montanide ISA 51 increased the percentage of GAR. There is a direct relationship between anti-EGF antibody titers and immune response duration with survival time.

Pharmacological evaluation of humanized anti-epidermal growth factor receptor, monoclonal antibody h-R3, in patients with advanced epithelial-derived cancer

Epidermal growth factor receptor (EGFR) overexpression has been detected in many tumors of epithelial origin, and it is often associated with tumor growth advantages and poor prognosis. h-R3 is a genetically engineered humanized antibody (mAb) that recognizes an epitope located in the extracellular domain of human EGFR. The antibody exhibited potent in vitro and in vivo antitumor effect on EGFR overexpressing cell lines. To study safety, pharmacokinetics, and biodistribution, 12 patients with advanced epithelial-derived tumors received single intravenous infusion of h-R3 at four dose levels. Safety evaluation was made according to World Health Organization toxicity criteria. For biodistribution, 3 mg of the total dose were labeled with Technetium and then pooled with the rest of the dose. Anterior and posterior whole-body images were acquired using a gamma camera. Blood samples were taken for pharmacokinetics, antiidiotypic response, and for soluble EGFR detection. After hR3 administration, no evidence of severe toxicity was observed. Secondary reactions were mild and moderate and mainly consisted of tremors, fever, and vomiting. No anaphylactic or skin reactions were detected. Qualitative analysis of whole-body images showed that the liver had the highest mAb uptake. Pharmacokinetic analysis revealed that elimination half-lives and the AUC increased linearly with dose, while total body clearance decreased when increasing doses of h-R3. No relation between shed EGFR and mAb clearance was found. No antiidiotypic response against h-R3 was detected. Several phase II trials are now underway to evaluate the efficacy of h-R3 in the treatment of advanced cancer patients.

Phase I clinical evaluation of a neutralizing monoclonal antibody against epidermal growth factor receptor

Ior egf/r3, a neutralizing monoclonal antibody (mAb) against Epidermal Growth Factor Receptor (EGFR) was generated at the Cuban Institute of Oncology. Immunoscintigraphic studies in 148 patients with this 99-m Technetium (99Tc) labeled mAb, showed a high sensitivity and specificity for in vivo detection of epithelial tumors. To study safety, pharmacokinetic and immunogenicity of ior egf/r3 at high doses, a phase I clinical trial was conducted. Nineteen patients with advanced epithelial tumors received 4 mAb intravenous infusions at 6 dose levels: from 50 to 500 mg. Previously, immunoscintigraphic images using the same mAb labeled with 99Tc were acquired. Blood samples were collected for pharmacokinetic analysis and HAMA response. After mAb therapy, objective response was classified according to WHO criteria. Ior egf/r3 was well tolerated in spite of the high-administered doses. Only a severe adverse reaction consisting of hypotension and lethargy was observed. In 13 patients, selective accumulation of 99Tc-labeled mAb was observed at the site of the primary tumor or the metastasis. Pharmacokinetic analysis revealed that elimination half-life and the area under the time-concentration curve increased linearly with dose. HAMA response was detected in 17 patients. After 6 months of mAb therapy, 4 patients had stable disease. One patient had a tumor partial remission after 3 cycles of ior egf/r3.