A phase I study of a DNA plasmid based vaccine encoding the HER2/neu (HER2) intracellular domain (ICD) in subjects with HER2+ breast cancer

3054

Background: HER2 is overexpressed in 25% of breast cancers and plays a role in the malignant transformation of cells. Vaccine-induced immunity against the HER2 ICD correlates with antitumor responses in animal models. DNA-based vaccines offer a strategy to immunize against multiple tumor antigens and are able to elicit both CTL and T helper immune responses. Plasmid DNA can also remain at the vaccine site, providing a constant source of antigen. However, DNA vaccines have been poorly immunogenic due in part to inefficient APC transfection. Intradermal (i.d.) delivery of DNA vaccines with GM-CSF as adjuvant may enhance immunogenicity due to local influx of dermal Langerhans cells. A phase I study was conducted to evaluate the safety and immunogenicity of a DNA-based vaccine encoding the HER2 ICD. Methods: 44 subjects with stage III and IV HER2+ breast cancer in complete remission were enrolled sequentially into 2 vaccine arms (22 subjects/arm) and received 10μg pNGVL3-hICD (Arm 1) or 100μg pNGVL3-hICD (Arm 2). All vaccines were admixed with 100μg GM-CSF and given i.d. monthly for a total of 3 vaccines. Toxicity was assessed at baseline, during vaccination, and at follow-up. Immune responses were assessed with IFN-γ ELISPOT at baseline and post-vaccination. Vaccine site biopsies were analyzed for plasmid persistence via RT-PCR, 1 and 6 months after vaccination. Results: 43 subjects (21 in Arm 1; 22 in Arm 2) completed 3 vaccines. Vaccine-related toxicity in both arms was primarily grade I/II; no cardiac or grade IV toxicity was observed. 13/21 (62%) subjects in Arm 1 developed T-cell immunity, defined as HER2-specific T cell precursors:PBMC, to the HER2 protein (median 1:5,972, range 1:717–1:3,000,000) and to p776, a HER2 pan DR binding epitope (median 1:3,150, range 1:543–1:108,696). 13/19 (68%) subjects in Arm 1 had persistent plasmid DNA at the vaccine site. ELISPOT and RT-PCR analysis for Arm 2 are on-going. Conclusions: Immunization with a DNA plasmid-based HER2 vaccine is safe and immunogenic. Moreover, plasmid DNA persists at the vaccine site post-immunization and HER2+ cancer patients are able to develop immunity to the HER2 ICD.

No significant financial relationships to disclose.

Association of the level of HER2/neu (HER2) gene amplification in breast cancer and the magnitude of antigen specific T-cell immunity achieved after HER2 vaccination

3059

Background: Studies have demonstrated that the level of HER2 gene amplification in breast cancer, assessed by fluorescence in situ hybridization (FISH), correlates with favorable clinical response after treatment with trastuzumab. We questioned whether HER2 gene amplification impacted the development of HER2-specific T-cell immunity following immunization with a HER2 vaccine. Methods: Patients with HER2+ stage III or IV breast cancer, treated to complete remission or stable bone only disease, were enrolled in one of two concurrent clinical trials of HER2-specific vaccines. Eligibility criteria between the two studies were similar. Patients received either a plasmid DNA-based vaccine encoding the HER2 intracellular domain or a peptide-based vaccine composed of 3 HER2 class II epitopes. Peripheral blood was assessed for HER2-specific T-cell responses by interferon gamma (IFN-g) ELISPOT prior to, immediately after, and 6 months to 1 year after the end of vaccinations. Both immune response and FISH data were available on 31 patients. Results: Correlation of FISH levels to IFN-g spots/well in evaluable patients revealed the level of HER2 gene amplification was not related to the presence of pre-existent HER2-specific T-cell immunity prior to vaccination (p=0.43), the generation of a HER2-specific immune response after vaccination (p=0.35), or the persistence of the HER2-specific T-cell response (p=0.33). However, the magnitude of the T-cell response achieved was less as HER2 gene amplification increased (p=0.05). Conclusions: The level of HER2 gene amplification in the primary tumor can adversely impact the magnitude of HER2-specific T-cell immunity achieved after vaccination.

No significant financial relationships to disclose.

Sources of referral to early phase clinical trials: a case for putting all your eggs in one basket

Abstract #3116

Background: Studies suggest that only 2% to 3% of all adult cancer patients and approximately 5% of breast cancer patients enroll in clinical trials. To better understand the factors that contribute to enrollment we collected data from patients on sources that prompted them to contact us.
 Methods: From Jan 2005 to Apr 2008 we screened nearly 400 patients for 8 Phase I/II clinical trials focused on immunotherapy of breast and ovarian cancer. We queried subjects about informational sources that led them to consider our clinical studies. Patients learned about our trials from sources including: Clinicians, the Internet (advocacy group websites, search engines, government/university sites), Other patients, Family/friends, Media, Community events and Postings seeking research participants. Many patients who cited a clinician as their referral source specifically referenced a private, multi-site breast cancer clinic in Southern California with which our clinical group has formed a partnership, or consortium. To ensure that this was represented in the data and because the clinician category comprised a large percentage of the referral sources we split the category into 2 groups-one being the private practice in California (to be referred to as “consortium”) and the other being all other clinicians.
 Results: Of the 399 patients screened, 336 (84%) were considered potentially eligible for study. A total of 72 patients, or 18% of those screened have enrolled in one of our trials to date.
 Among patients screened, most learned about our trials from clinicians outside the consortium (34%), the Internet (27%), and consortium clinicians (15%). Patients most often named her2support.org (35%) and clinicaltrials.gov (23%) as their specific Internet sources. The remaining sources, family/friends, patients, media sources, community events and postings in medical facilities, were each cited by <5% of patients.
 Although consortium clinicians were responsible for only 15% of referrals, 50% of their referrals enrolled in a study. Only 16% of patients referred by other clinicians and 9% referred via the Internet were enrolled. Though other clinicians and the Internet are the most common referral sources, referrals from our consortium were significantly more likely to enroll than any other source (p<0.001).
 This may be due to the fact that patients referred by the consortium were more likely to meet eligibility criteria. Relative to 93% of consortium referrals, 87% of other clinician and 79% of Internet referrals were potentially eligible for trial (p<0.05). Patients referred by our consortium were significantly more likely to meet study criteria relative to those referred by other sources.
 Discussion: Physician referrals often lead to higher accrual to clinical trials relative to other referral sources. Our data reveal that accrual can be further improved by forming a close collaborative relationship with a single select practice of clinicians.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3116.

Multicenter retrospective development and validation of a clinical prediction rule for nosocomial invasive candidiasis in the intensive care setting

The study presented here was performed in order to create a rule that identifies subjects at high risk for invasive candidiasis in the intensive care setting. Retrospective review and statistical modelling were carried out on 2,890 patients who stayed at least 4 days in nine hospitals in the USA and Brazil; the overall incidence of invasive candidiasis in this group was 3% (88 cases). The best performing rule was as follows: Any systemic antibiotic (days 1-3) OR presence of a central venous catheter (days 1-3) AND at least TWO of the following-total parenteral nutrition (days 1-3), any dialysis (days 1-3), any major surgery (days -7-0), pancreatitis (days -7-0), any use of steroids (days -7-3), or use of other immunosuppressive agents (days -7-0). The rate of invasive candidiasis among patients meeting the rule was 9.9%, capturing 34% of cases in the units, with the following performance: relative risk 4.36, sensitivity 0.34, specificity 0.90, positive predictive value 0.01, and negative predictive value 0.97. The rule may identify patients at high risk of invasive candidiasis.

Endocrine outcome for children with embryonal brain tumors treated with craniospinal irradiation on the SJMB96 trial

9571

Background: To investigate the relationship between endocrine deficits with the radiation (RT) dose to the hypothalamic- pituitary axis (HPA) in medulloblastoma/PNET patients treated with risk-adapted craniospinal irradiation (CSI) followed by chemotherapy. Methods: 88 patients who survived at least 2 years from diagnosis were included in this analysis. CSI doses were 23.4 Gy or 36–39.6 Gy depending on clinical risk; the primary tumor site received 55.8 Gy. All pts had regular endocrine follow-up and screening to test for growth hormone (GH), thyroid hormone (TH) and adrenocorticotrophin hormone (ACTH) deficiency. Patients that had abnormal results on the screening tests underwent further evaluation by stimulation testing of the HPA. Only patients diagnosed with central hypothyroidism were included in the analysis for TH deficiency. Results: Of the 88 pts included in the study cohort, 77 pts had abnormal screening tests and underwent provocative testing. The median radiation dose to the hypothalamus was 42 Gy (26–57 Gy) and pituitary was 44 Gy (26–58 Gy). Patients receiving higher RT doses to the pituitary had a significantly higher incidence of growth hormone deficiency with 4-year estimates of 100 ±3% for those receiving = 44Gy and 82±7% for those receiving < 44 Gy (p=0.024). Four-year estimates of thyroid hormone deficiency for patients receiving = 44 Gy to the pituitary were 67±21% and 18±14% for those receiving < 44 Gy (p<0.010). There was no correlation between the dose to the pituitary with the incidence of ACTH deficiency. The estimated change in height z-score for patients receiving < 44 Gy to the pituitary was - 0.53 units per year (-0.44 to -0.63) compared with -0.70 units per year (-0.62 to -0.78) for those receiving = 44 Gy. Conclusions: Data from this prospective study demonstrate that RT to the HPA is the key determinant for developing endocrinopathies in patients with medulloblastoma/PNET.

No significant financial relationships to disclose.

Role of amifostine as a cytoprotectant in children ≥ 3 years with average risk (AR) medulloblastoma (MB) treated with craniospinal irradiation (CSI) and 4 courses of cisplatin (CDDP)-based high dose chemotherapy

9063

Background: Therapy for MB (CSI and CDDP-based chemotherapy) results in hearing loss before completion of therapy in 30%-50% of patients, who consequently require a reduced cisplatin dose. Cytoprotection against cisplatin-induced ototoxicity may be provided by amifostine, a thiol prodrug that protects many normal tissues against therapy-induced damage without diminishing antitumor effects. Method: This study was designed to detect a 20% decrease (80% power) in CDDP induced ototoxicity (defined as needing hearing aids) in AR MB patients with the use of amifostine (n=62) compared to historical controls (n=35) one year from diagnosis. An interim analysis was conducted after accrual of 32 pts on the experimental arm. A total of 67 AR MB patients received CSI (23.4 Gy) followed by 3-dimensional conformal boost to the tumor bed (total 55.8 Gy) and 4 cycles of high-dose cyclophsophamide (4,000 mg/m2 per cycle), cisplatin (75 mg/m2 per cycle), and vincristine (two 1.5 mg/m2 doses per cycle). When used, amifostine (600 mg/m2 per cycle) was given before and 3 hours into the cisplatin infusion. Results: The median age of the 40 male, 27 female patients was 8.7 (range, 3.2–20.2) yrs. The 2 groups had similar median ages (amifostine, 9.1; control, 7.8 years) and gender (male: amifostine, 66%; control, 54%). One year after the start of treatment, the objective criteria for needing a hearing aid in at least 1 ear were met by 13 (37%) of control-group patients and 6 (18.8%) of those who received amifostine. Conclusion: The interim analysis has demonstrated that the need for hearing aids in AR MB children treated with the above-described regimen is halved by using amifostine during CDDP administration.

No significant financial relationships to disclose.

Rofecoxib versus Hydrocodone/Acetaminophen for Postoperative Analgesia in Functional Endoscopic Sinus Surgery

OBJECTIVES/HYPOTHESIS

Functional endoscopic sinus surgery (FESS) is less invasive and more tissue sparing than extirpative techniques, with an assumed benefit of diminished postoperative pain. Oral opioids are commonly prescribed after sinus surgery but are associated with adverse effects, including gastrointestinal and neurologic symptoms. Nonopioid analgesics have been suggested to offer similar pain control efficacy with fewer adverse effects.

STUDY DESIGN

To investigate postoperative analgesia in FESS, a prospective randomized, double-blinded comparison of hydrocodone/acetaminophen 7.5/750 mg (an opioidderivative) with rofecoxib 50 mg (a cyclooxygenase-2 inhibitor) was performed.

METHODS

Forty subjects were enrolled, of which 28 successfully completed the study. Subjects recorded peak pain levels and requirement for rescue analgesia on the day of surgery and for 4 days thereafter. On postoperative day 5, subjects completed an exit survey in which adverse effects and overall satisfaction with pain control were recorded.

RESULTS

In this study, there were no statistical differences in peak pain levels between the groups at any point in the postoperative period, regardless of extent of surgery. Adverse effect profiles were also similar for the two groups.

CONCLUSIONS

The use of nonopioid analgesics after FESS may provide similar pain control to oral opioids.

Altered CD45 expression in C77G carriers influences immune function and outcome of hepatitis C infection

BACKGROUND

A polymorphism in exon 4 (C77G) of CD45 that alters CD45 splicing has been associated with autoimmune and infectious diseases in humans.

OBJECTIVE

To investigate the effect of C77G in hepatitis C virus (HCV) infected individuals and study the phenotype and function of peripheral blood mononuclear cells (PBMC) from healthy and hepatitis C infected C77G carriers.

RESULTS

C77G individuals showed an increased proportion of primed CD45RA and effector memory CD8 T cells and more rapid activation of the lymphocyte specific protein tyrosine kinase (Lck) following CD3 stimulation. Transgenic mice with CD45 expression mimicking that in human C77G variants had more activated/memory T cells, more rapid proliferative responses, and activation of Lck.

CONCLUSIONS

Changes in CD45 isoform expression can alter immune function in human C77G variants and CD45 transgenic mice. The C77G allele may influence the outcome of HCV infection.

An unusual presentation of metastatic testicular tumour

We report a unique case of metastatic malignant teratoma from an undescended testis which presented with acute pulmonary embolism. After chemotherapy, the undescended right testicle was resected along with a cord of non- obstructing inferior venal caval tumour which extended into the right atrium with tumour floating free within the atrium at the end of the cord of tumour. The presentation, diagnosis and treatment of testicular tumours is described and the literature pertaining to testicular tumours in military personnel reviewed.

Ginkgo biloba and Acetazolamide Prophylaxis for Acute Mountain Sickness

BACKGROUND

Acute mountain sickness (AMS) commonly occurs when unacclimatized individuals ascend to altitudes above 2000 m. Acetazolamide and Ginkgo biloba have both been recommended for AMS prophylaxis; however, there is conflicting evidence regarding the efficacy of Ginkgo biloba use. We performed a randomized, placebo-controlled trial of acetazolamide vs Ginkgo biloba for AMS prophylaxis.

METHODS

We randomized unacclimatized adults to receive acetazolamide, Ginkgo biloba, or placebo in double-blind fashion and took them to an elevation of 3800 m for 24 hours. We graded AMS symptoms using the Lake Louise Acute Mountain Sickness Scoring System (LLS) and compared the incidence of AMS (defined as LLS score > or =3 and headache).

RESULTS

Fifty-seven subjects completed the trial (20 received acetazolamide; 17, Ginkgo biloba, and 20, placebo). The LLS scores were significantly different between groups; the median score of the acetazolamide group was significantly lower than that of the placebo group (P=.01; effect size, 2; and 95% confidence interval [CI], 0 to 3), unlike that of the Ginkgo biloba group (P=.89; effect size, 0; and 95% CI, -2 to 2). Acute mountain sickness occurred less frequently in the acetazolamide group than in the placebo group (effect size, 30%; 95% CI, 61% to -15%), and the frequency of occurrence was similar between the Ginkgo biloba group and the placebo group (effect size, -5%; 95% CI, -37% to 28%).

CONCLUSIONS

In this study, prophylactic acetazolamide therapy decreased the symptoms of AMS and trended toward reducing its incidence. We found no evidence of similar efficacy for Ginkgo biloba.

Ossifying fibroma of the jugum sphenoidale

We report a rare case of an eight year old boy with an ossifying fibroma of the jugum sphenoidale who presented with rapid onset bilateral blindness. This benign tumour was initially debulked and required re-operation with decompression of both optic nerves due to progressive visual deterioration. Post-operatively, there was good visual recovery in the left eye, but visual acuity in the right eye remained at <1/60. A 17 years follow period is described, in which there has been no clinical or radiological evidence of tumour recurrence.

A link between irritable bowel syndrome and fibromyalgia may be related to findings on lactulose breath testing

BACKGROUND

An association between irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO) has been found.

OBJECTIVE

To compare the prevalence and test results for bacterial overgrowth between IBS and fibromyalgia.

METHODS

Subjects with independent fibromyalgia and IBS were compared with controls in a double blind study. Participants completed a questionnaire, and a lactulose hydrogen breath test was used to determine the presence of SIBO. The prevalence of an abnormal breath test was compared between study participants. Hydrogen production on the breath test was compared between subjects with IBS and fibromyalgia. The somatic pain visual analogue score of subjects with fibromyalgia was compared with their degree of hydrogen production.

RESULTS

3/15 (20%) controls had an abnormal breath test compared with 93/111 (84%) subjects with IBS (p<0.01) and 42/42 (100%) with fibromyalgia (p<0.0001 v controls, p<0.05 v IBS). Subjects with fibromyalgia had higher hydrogen profiles (p<0.01), peak hydrogen (p<0.0001), and area under the curve (p<0.01) than subjects with IBS. This was not dependent on the higher prevalence of an abnormal breath test. The degree of somatic pain in fibromyalgia correlated significantly with the hydrogen level seen on the breath test (r = 0.42, p<0.01).

CONCLUSIONS

An abnormal lactulose breath test is more common in fibromyalgia than IBS. In contrast with IBS, the degree of abnormality on breath test is greater in subjects with fibromyalgia and correlates with somatic pain.

Deletion of the alpha1 or beta2 subunit of GABAA receptors reduces actions of alcohol and other drugs

Enhancement of the activation of GABAA receptors is a common feature of many sedative and hypnotic drugs, and it is probable that the GABAA receptor complex is a molecular target for these drugs in the mammalian central nervous system. We set out to elucidate the role of the two predominant (alpha1 and beta2) subunits of GABAA receptor in sedative drug action by studying mice lacking these two subunits. Both alpha1 (-/-) and beta2 (-/-) null mutant mice showed markedly decreased sleep time induced by nonselective benzodiazepine, flurazepam, and GABAA agonist, 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol. The sleep time induced by the beta-selective drug etomidate was decreased only in beta2 (-/-) knockout mice. In contrast, alpha1 (-/-) mice were more resistant to the alpha1-selective drug zolpidem than beta2 (-/-) or wild-type animals. Knockout mice of both strains were similar to wild-type mice in their responses to pentobarbital. The duration of loss of the righting reflex produced by ethanol was decreased in male mice for both null alleles compared with wild-type mice, but there were no differences in ethanol-induced sleep time in mutant females. Deletion of either the alpha1 or beta2 subunits reduced the muscimol-stimulated 36Cl36 influx in cortical microsacs suggesting that these mutant mice have reduced number of functional brain GABAA receptors. Our results show that removal of either alpha1 or beta2 subunits of GABAA receptors produce strong and selective decreases in hypnotic effects of different drugs. Overall, these data confirm the crucial role of the GABAA receptor in mechanisms mediating sedative/hypnotic effects.

Hyperactivity and dopamine D1 receptor activation in mice lacking girk2 channels

RATIONALE

G-protein-coupled inwardly rectifying potassium channels (GIRKs) regulate synaptic transmission and neuronal firing rates. Co-localization of GIRK2 channels and dopamine receptors in the mesolimbic system suggests a role in regulation of motor activity.

OBJECTIVES

To explore the role of GIRK channels in the regulation of motor behavior.

METHODS

GIRK2 null mutant mice (knockout) were used. Locomotor activity in a mildly stressful situation was conducted either in a circular open field with video tracking or in standard mouse cages equipped with infrared sensors. Drugs were injected intraperitoneally or subcutaneously.

RESULTS

GIRK2 knockout mice demonstrated a transient "hyperactive" behavioral phenotype with initially higher motor activity and slower habituation in a novel situation, increased levels of spontaneous locomotor activity during dark phase in their home cages, and impaired habituation in the open-field test. After habituation, GIRK2 knockout mice showed higher motor activity, which was inhibited by the D(1) receptor antagonist SCH 23390 and was more sensitive to the activating effects of the D(1) receptor partial agonist SKF 38393. In a novel environment (open-field) only the highest dose of SKF 38393 used (20 mg/kg) produced significant activation, perhaps due to a ceiling effect in GIRK2 knockout mice. SCH 23390 inhibited the basal activity levels of mice of both genotypes.

CONCLUSIONS

Activation of the dopamine D(1)receptor in a stressful environment may be stronger in GIRK2 deficient mice, and this modified function of D(1) receptors may cause the transient hyperactive behavioral phenotype of these mice.