Local and Systemic Immunity During Five Vaccinations Against SARS-CoV-2 in Zanubrutinib-Treated Patients With Chronic Lymphocytic Leukemia

Background

Patients with chronic lymphocytic leukemia (CLL) are vulnerable to coronavirus disease 2019 (COVID-19) and are at risk of inferior response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, especially if treated with the first-generation Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib. We aimed to evaluate the impact of the third-generation BTKi, zanubrutinib, on systemic and mucosal response to SARS-CoV-2 vaccination.

Methods

Nine patients with CLL with ongoing zanubrutinib therapy were included and donated blood and saliva during SARS-CoV-2 vaccination, before vaccine doses 3 and 5 and 2 - 3 weeks after doses 3, 4, and 5. Ibrutinib-treated control patients (n = 7) and healthy aged-matched controls (n = 7) gave blood 2 - 3 weeks after vaccine dose 5. We quantified reactivity and neutralization capacity of SARS-CoV-2-specific IgG and IgA antibodies (Abs) in both serum and saliva, and reactivity of T cells activated with viral peptides.

Results

Both zanubrutinib- and ibrutinib-treated patients had significantly, up to 1,000-fold, lower total spike-specific Ab levels after dose 5 compared to healthy controls (P < 0.01). Spike-IgG levels in serum from zanubrutinib-treated patients correlated well to neutralization capacity (r = 0.68; P < 0.0001) and were thus functional. Mucosal immunity (specific IgA in serum and saliva) was practically absent in zanubrutinib-treated patients even after five vaccine doses, whereas healthy controls had significantly higher levels (tested in serum after vaccine dose 5) (P < 0.05). In contrast, T-cell reactivity against SARS-CoV-2 peptides was equally high in zanubrutinib- and ibrutinib-treated patients as in healthy control donors.

Conclusions

In our small cohort of zanubrutinib-treated CLL patients, we conclude that up to five doses of SARS-CoV-2 vaccination induced no detectable IgA mucosal immunity, which likely will impair the primary barrier defence against the infection. Systemic IgG responses were also impaired, whereas T-cell responses were normal. Further and larger studies are needed to evaluate the impact of these findings on disease protection.

Abstract 3184: Differential expression of viral agents in lymphoma tissues of patients with ABC diffuse large B-cell lymphoma from high and low endemic infectious disease region

Environmental factors play an important role in the development of cancer. Infectious organisms are one of the major causes of cancer among environmental factors. Several viruses have been classified as infectious agents causing cancer as EBV, HTLV-1, herpes virus-8 and hepatitis. Since the introduction of vaccines against viral infections as HPV and HBV, the incidence of cervical cancer and HCC respectively has decreased.

The aim of the study was to investigate the detection of viral and microbial agents in the lymphoma tissues of ABC DLBCL patients from Sweden (low infectious disease region) and Egypt (high infectious disease region) according to WHO classification. Microbial detection array (MDA) technique was used to identify viral detection in the tissue samples as well as antigen and antibody detection of serum samples of patients.

A differential detection of viruses in lymphoma tissues was noted comparing Swedish and Egyptian patients. Viruses that were detected in all groups (both controls and patients) were excluded leaving exclusively found viruses in each group. HBV had the highest expression including the complete genome and was only found in Egyptian patients. JCV was found both in Egyptian and Swedish patients but with a higher expression in the Egyptian patients while not detected in Swedish and Egyptian controls. Generally, the highest expressions were found in Egyptian patients compared to Swedish patients and controls from both countries. Few viruses were found in the control groups.

Based on serum HBV PCR, Egyptian patients were divided into a HBV antigen positive (HBV+) and HBV negative (HBV-) group. The relative expression of STAT3 did not differ between HBV+ and HBV- Egyptian patients but was significantly higher in the Swedish patients compared to the total Egyptian patient population. Since, miR-1234 might regulate STAT3, we also related the relative miR-1234 expression to HBV status. There was no difference in the relative expression of miR-1234 between HBV+ and HBV- Egyptian patients, while Swedish patients (HBV-) showed a significantly lower relative expression of miR-1234, compared to the total Egyptian patient population. miR-1234 related inversely to the expression patterns of STAT3.

The results indicate that Egyptian patients have a higher viral load and that HBV was the most common virus. However, our results may be of importance for treatment strategies in Egyptian patients since previous data have shown HBV reactivation in patients from high endemic infectious area during Rituximab treatment.

In summary, indicated that viral agents as JCV and HBV may be involved in the tumorigenesis of ABC DLBCL. We could not detect a relation of STAT3 expression to HBV. However, the regulation of STAT3 by miR-1234 might be associated to other viral infections and to the higher viral load as noted in the Egyptian patients.

Citation Format: Ali Moshfegh, Therese Högfeldt, Crystal Jaing, Joachim Lundahl, Anders Osterborg, Kevin Mc Loughlin, Shea N. Gardner, Baback Gharizadeh, Anna Porwit, Abeer A. Bahnassy, Abdel-Rahman N. Zekri, Hussein M. Khaled, Hakan Mellstedt. Differential expression of viral agents in lymphoma tissues of patients with ABC diffuse large B-cell lymphoma from high and low endemic infectious disease region. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3184. doi:10.1158/1538-7445.AM2014-3184

Apoptosis induction mediated through PI3-kinase/AKT/mTOR pathway using anti-ROR1 monoclonal antibody in chronic lymphocytic leukemia cells

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Background: The PI3K/AKT/mTOR is a central pathway activated in many types of cancer. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase regulating cell growth, proliferation and survival. In CLL cells PI3K pathway is constitutively activated leading to AKT activation with subsequent phosphorylation of other downstream signaling molecules. ROR1 is a type I transmembrane RTK, overexpressed and constitutively phosphorylated in CLL. A unique anti-ROR1 mAb directed against CRD region of ROR1 was capable of inducing direct apoptosis as well as dephosphorylating the ROR1 molecule. Here, we investigated the apoptotic effect of the anti-ROR1 mAb and effects on the PI3K/AKT/mTOR pathway using primary CLL cells. Methods: Apoptosis was detected by the MTT assay and Annexin V/PI methods in a 24 h assay. Antibody untreated and treated cell lysates were prepared and subjected to Western blot analysis for identification of the signaling molecules involved in apoptosis induced by the ROR1 mAb. We analysed total and phosphorylated levels of the following signaling proteins: AKT, p-AKT, PI3K, p-PI3K, mTOR, p-mTOR, ERK, p-ERK, PKC and p-PKC. Phosphoproteins were measured before incubation with the mAb and after 20 min-24 h. Results: ROR1 detection on surface of the CLL cells was 80-85% and apoptotic frequency 45-50%. Western blot analysis showed decreased levels of p-AKT, p85 isoform of p-PI3K and p-mTOR in treated compared to untreated samples. No changes in the phosphorylation levels of ERK and PKC proteins were seen. Conclusions: Incubation of CLL cells with the anti-ROR1 mAb induced apoptosis of CLL cells. Apoptosis was preceded by dephosphorylation of PI3K, AKT and mTOR proteins indicating deactivation of these proteins by the ROR1 mAb. In untreated CLL cells no effect was noted. Furthermore no dephosphorylation of PKC or ERK was seen. We suggest that activation of mTOR might occur via the PI3K/AKT pathway and may be a survival signal in CLL cells associated with the aberrant expression of ROR1. Further studies are warranted to understand better the signaling pathways associated with ROR1 and the downstream signaling effects of ROR1 targeting drugs.

Awareness and understanding of cancer immunotherapy in Europe

3053

Background: Use of immunotherapies in the treatment of cancer is growing and a range of new immunotherapeutic strategies are being evaluated. It is important that healthcare providers (HCP) understand these treatments and how they compare with and may complement established therapies. As part of the activities of the POINT expert group, we commissioned a survey of current awareness, attitudes and perceptions of cancer immunotherapy in Europe. Methods: From August-September 2011, 426 healthcare professionals (HCPs: oncologists, surgeons and oncology nurses) from France, Germany, Italy, Spain and the UK (~85 respondents/country) completed online interviews. Representatives of patient advocacy groups (PAGs) in each country were surveyed by telephone interview. Results: Nearly all (98%) HCPs were aware of cancer immunotherapy. While 68% of HCPs indicated a high level of interest, knowledge levels were lower. Only 24% of the HCPs had direct experience with cancer immunotherapies, while others reported they knew a lot (12%), a reasonable amount (28%) or little (34%) about immunotherapy strategies but had not used them (76%). Overall perceptions of cancer immunotherapy among HCPs were largely positive (60%) and rarely negative (3%). The key advantages of cancer immunotherapy were perceived to be good safety and tolerability (75%), a targeted mechanism of action (61%) and good efficacy (48%). The leading barriers to use of immunotherapies were costs of treatment (58%), past clinical trial failures (45%) and access/formulary restrictions (44%). Most (75%) HCPs had already discussed cancer immunotherapy with their patients and 70% of patients were reported as being receptive to the concept. The majority of PAGs indicated they were currently unable to advise patients about cancer immunotherapy due to a lack of or confusing information and poor understanding. Conclusions: Awareness of cancer immunotherapy in Europe is high and it is generally perceived as a positive addition to established treatment options. However, the understanding varies and the direct experience is limited. There is a clear need for further educational activities concerning cancer immunotherapy, as well as further clinical data on long-term efficacy and safety.

Inhibition of the receptor tyrosine kinase ROR1 by anti-ROR1 monoclonal antibodies and siRNA induced apoptosis of melanoma cells

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Background: The receptor tyrosine kinase ROR1 has important functions during normal embryogenesis. It is overexpressed and of importance for the survival of different malignancies, including lung adenocarcinoma, breast cancer and chronic lymphocytic leukemia (CLL). ROR1 inhibition in CLL cells and cell lines with high expression of ROR1 induced specific apoptosis of the cells. There is however little information on the expression and function of ROR1 in melanoma. Here, we investigated ROR1 expression, phosphorylation and the effects of anti-ROR1 monoclonal antibodies (mAbs) and ROR1 suppressing siRNA on seven melanoma cell lines. Methods: ROR1 expression and phosphorylation was analysed in a series of malignant melanoma cell lines using RT-PCR, immunocytochemistry, flow cytometry and western blot. Annexin V/PI staining, MTT assay, PARP and caspase 8 and 9 cleavage as well as MCL-1 protein were used for detection of apoptosis induced by anti-ROR1 mAbs. The cytotoxic effects of anti-ROR1 mAbs were evaluated in the absence or presence of complement (CDC) or immune effector cells (ADCC). Transfection of melanoma cell lines using ROR1 siRNA was used for gene silencing. Results: ROR1 was shown to be overexpressed to a varying degree at protein level. ROR1 was phosphorylated at tyrosine and serine residues. Three out of four anti-ROR1 mAbs (clones 3H9, 5F1 and 1A8) induced a significant direct apoptosis of the ESTDAB049, ESTDAB112, DFW and A375 cell lines as well as cell death in the presence of complement or immune effector cells. ESTDAB081 and 094 cell lines were resistant to direct apoptosis of the four anti-ROR1 mAbs alone compared to the other melanoma cell lines, but not to complement dependent cytotoxicity (CDC) and antibody dependent cell mediated cytotoxicity (ADCC). ROR1 siRNA transfection induced down-regulation of the ROR1 expression both at the mRNA and protein levels proceeded by a significant apoptosis of the melanoma cells. Conclusions: The results indicate that ROR1 may play an important role in the survival of melanoma cells. The surface expression of ROR1 on melanoma cells may support the notion that ROR1 might be a suitable targeted for mAb therapy.

Inhibition of the receptor tyrosine kinase ROR1 by anti-ROR1 monoclonal antibodies and siRNA induced apoptosis of melanoma cells

The receptor tyrosine kinase (RTK) ROR1 is overexpressed and of importance for the survival of various malignancies, including lung adenocarcinoma, breast cancer and chronic lymphocytic leukemia (CLL). There is limited information however on ROR1 in melanoma. In the present study we analysed in seven melanoma cell lines ROR1 expression and phosphorylation as well as the effects of anti-ROR1 monoclonal antibodies (mAbs) and ROR1 suppressing siRNA on cell survival. ROR1 was overexpressed at the protein level to a varying degree and phosphorylated at tyrosine and serine residues. Three of our four self-produced anti-ROR1 mAbs (clones 3H9, 5F1 and 1A8) induced a significant direct apoptosis of the ESTDAB049, ESTDAB112, DFW and A375 cell lines as well as cell death in complement dependent cytotoxicity (CDC) and antibody dependent cellular cytotoxicity (ADCC). The ESTDAB081 and 094 cell lines respectively were resistant to direct apoptosis of the four anti-ROR1 mAbs alone but not in CDC or ADCC. ROR1 siRNA transfection induced downregulation of ROR1 expression both at mRNA and protein levels proceeded by apoptosis of the melanoma cells (ESTDAB049, ESTDAB112, DFW and A375) including ESTDAB081, which was resistant to the direct apoptotic effect of the mAbs. The results indicate that ROR1 may play a role in the survival of melanoma cells. The surface expression of ROR1 on melanoma cells may support the notion that ROR1 might be a suitable target for mAb therapy.

Different dose regimens of the mouse monoclonal-antibody 17-1a for therapy of patients with metastatic colorectal-carcinoma

Seventy-one patients with metastatic colorectal carcinoma(CRC) were treated with varying doses of the mouse monoclonal antibody (MAb) 17-1A. One patient achieved a partial remission (PR) (1%) with a survival duration of 114+ months. Further 10 patients showed a minor response (MR) or stable disease > 3 months (SD) (14%). In patients receiving a total dose of MAb17-1A < 2 g the overall response rate was 22% (10/45) (1 PR, 2 MR, 7 SD) while patients treated with a total dose > 2 g had a corresponding figure of 4% (1/26) (1 MR) (p < 0.05). Responding patients (n = 11) survived significantly longer than non-responding patients (n = 60) (median: 20 vs 10 months) (p < 0.0027). In the most intensive treatment group (total 12 g), 14 patients received 500 mg of MAb17-1A tiw for 8 weeks. The frequency and intensity of side-effects were mild and did not cause withdrawal or dose reduction of MAb17-1A, even in the 12 g dose schedule. Patients with a pretreatment ADCC (antibody dependent cellular cytotoxicity) activity above the median of all patients, survived significantly longer than those with a low value (p < 0.05).

Metabolic intervention targeting 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) using a structure-based design

e13518

Background: By producing fructose-2,6-bisphosphate, PFKFB3 functions as an activator of anaerobic glycolysis. PFKFB3 is both over expressed and over activated in many of the types of human cancer. Specific inhibition of the PFKFB3 enzyme results in a reduction in metabolism and cell growth in oxygen-deficient cancer environments. Methods: High-throughput screening. Medicinal Chemistry. Structure-Based Drug Design, X-ray Crystallography. NMR. Isothermal Calorimetry. Dynamic Light Scatttering. ADME. Results: A high-throughput screening of 50.000 selected compounds, by means of a biochemical assay, generated 105 hits including both ATP-and non-ATP competitive hits as identified by NMR binding experiments. The latter type was prioritized and two hits with a similar “ring-linker-ring structure” were selected for further expansions. Interestingly, although structurally similar, the two hits were found by means of X-ray crystallography to exhibit different binding modes within the fructose pocket. Based on their respective binding mode, two chemical series were developed displaying different ADME properties and PFKFB isoenzyme selectivity. Calorimetry verified a reversible strong enthalpy driven, direct binding for both chemical series. A third chemical series was developed towards yet another unoccupied binding pocket within the fructose-site, yielding a 5-fold increase in potency. Strong interactions within the new pocket were confirmed using X-ray crystallography. Our PFKFB3 inhibitors were shown to reduce tumor cell growth in vitro and to exhibit combinatory effects with Cisplatin. Conclusions: We have targeted the fructose-binding pocket of PFKFB3, developed compounds with nM binding potency and have gained a detailed understanding of SAR via structural information. The structure-based analysis has provided a good understanding of the molecular interactions, which is important for further biological/clinical positioning: e.g., combination with chemotherapy, optimization of PK properties and proof of principle in vivo.

Prognostic value of epithelial cell adhesion molecule (EpCAM) in patients with primary epithelial ovarian cancer

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Background: EpCAM, a well known cancer antigene is currently experiencing a renaissance in its use as a binding site for targeted oncologic therapy and prognostic marker in various epithelial carcinomas such as breast cancer or carcinomas of the oral cavity. Goal of this retrospective study was to identify EpCAM as a potential prognostic marker for patients with primary epithelial ovarian cancer (EOC). Methods: EpCAM expression was assessed in tumor tissue by immunohistochemistry using the Avidin-Biotin-Complex method on paraffin-embedded ovarian cancer tissue samples. EpCAM overexpression was defined as an expression of EpCAM as high as 76-100%. Clinical data as well as tumor tissue samples were collected within the validated “Tumor bank Ovarian Cancer Network (TOC)”. Results: Seventy-four patients with the primary diagnosis of EOC between 01/1994 and 12/2009 were included in this study. Median age at diagnosis was 56 years. The vast majority of the patients (75.4%) presented an advanced stage disease (FIGO III/IV). Forty-one (55.4%) patients were diagnosed with a serous, 19 (25.6%) a endometrioid and 14 (19%) a mucinous histology. EpCAM was overexpressed in 87.7% of the patients. Serous tumors expressed EpCAM in significantly higher rates than mucinous tumors ( p=0.045). EpCAM overexpression correlated in univariate analysis with a significantly better overall survival. Multivariate analysis including histological subtype identified EpCAM expression of 76-100% to be independently associated with a significantly better overall survival compared to a lower EpCAM expression of ≤50% (p=0.008). Conclusions: EpCAM overexpression in EOC appears to be associated with significantly higher overall survival rates. Larger, prospectively assessed multicenter studies are warranted to further evaluate and confirm these novel findings and possibly establish EpCAM as a potent therapeutic target in EOC.

Effect of ROR1-targeting small molecules on chronic lymphocytic leukemia (CLL) cells

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Background: There is a great interest to develop targeting drugs for CLL, both MAbs and small molecules, to improve the outcome for the disease. ROR1, a receptor tyrosine kinase, is overexpressed on CLL cells but not on normal cells. ROR1 is constitutively phosphorylated and siRNA transfection induces leukemic cell death. The aim of the study is to produce small molecules inhibiting the cytoplasmic tyrosine kinase activity of ROR1, which could induce specific killing of leukemic cells. Methods: A high-throughput screening assay in 384-format has been developed measuring phosphorylation of a substrate peptide by human recombinant intracellular ROR-1 kinase domain. A collection of 80.000 small molecules has been screened generating two chemical series. Novel leads have been synthesized and structure-activity-relationship has been developed using the assay. Results: Three compounds were selected (KAN0173631, KAN0438063, KAN0438175T). Freshly isolated leukemic CLL cells were used as targets in addition to PBMC from healthy donors to test cytotoxicity. The three compounds induced specific apoptosis of CLL cells (Annexin V/PI and MTT) both at 24 and 48h. Efficacy index (EI), i.e. killing of leukemic cells in relation to normal PBMC was favourable. The most promising drug KAN0438063 had an EI of 40 i.e. killed 40 times more CLL cells than PBMC at an IC50 of 10µM. The compounds induced PARP cleavage and cleavage of caspases 8 and 9 as well as down regulation of Mcl-1 and Bcl-xl (Western Blot). ROR1 was dephosphorylated (Western Blot). The selective apoptotic effect was compared to other small molecules targeting non-ROR1 structures in CLL (PCI-32765, CAL-101, R406, R788, STK-156485, STK-156133) and our compounds were significantly more effective (EI) (p<0.001). Conclusions: We have developed effective and selective series of compounds targeting ROR1 with promising ADMET properties. ROR1 targeting small molecules might also be effective for other tumor cells expressing ROR1 as has been noted for e.g. pancreatic carcinoma cells. Our model molecules will be further optimized and tested in animal tumor models. These molecules represent the first small molecules targeting ROR1 – a “survival factor” in CLL.

Cancer vaccines for non-small-cell lung cancer

Lung cancer is globally the second most common form of cancer in both men and women and the single largest cause of cancer-related mortality in the world. It is a disease with poor prognosis and the survival statistics have scarcely improved since historical times. The advent of targeted therapies has caused an incremental increase in survival figures. Nevertheless, significant progress in treatment outcomes need to be achieved before any perceptible improvement in overall survival of lung cancer patients becomes evident. The use of active-specific immunotherapy or cancer vaccines for the treatment of lung cancer is still in its infancy. Nevertheless several cancer vaccines have demonstrated clinical effects and improvements in overall survival in phase II and phase III trials and several more clinical trials are currently ongoing. This review summarizes the recent developments in NSCLC vaccines.

Intermittent melphalan and prednisolone therapy in plasma cell myeloma

Thirty-two consecutive, previously untreated patients with plasma cell myeloma were treated with 4-day courses of melphalan (0.25 mg/kg/day) and prednisolone (2 mg/kg/day) every sixth week. The observation period ranged from 26 to 75 months and the total median survival time was 29 months. 75% of the patients responded to therapy and their median survival time was 42 months. Sex did not influence either the response rate or the survival time. Most patients were treated in an out-patient clinic and required a minimum of check-ups.

Skin capillary abnormalities in patients with Raynaud's phenomenon

The digital skin microcirculation was studied by vital capillaroscopy in 32 consecutive patients with Raynaud's phenomenon. A detailed classification (stages 0-6) of the capillary abnormalities based upon observations of the capillaries in many different sites of the fingers was used. Associated diseases were searched for by an extensive clinical and immunological investigation. Seventeen (53%) of the patients had distinct structural changes in the capillaries but only 6 of them showed a restricted total digital circulation. Fifteen (88%) of these 17 patients displayed an underlying disease and/or immunological abnormalities. The corresponding figure for patients with mild or no capillary changes was 40% (p less than 0.01). Thus, the presence of marked (greater than or equal to stage 3) skin capillary abnormalities seems to be a good indicator of an associated systemic disease. The majority of patients in this category improved their capillary status during successful treatment of the underlying disease. We conclude that the form of capillaroscopy used in this study is a sensitive method for evaluating disturbances of the skin microcirculation in patients with Raynaud's phenomenon. The method may also contribute to the clinical evaluation of patients with this syndrome by identifying those with an underlying systemic disease.

Extreme hyponatremia in patients with myelomatosis: an effect of cationic paraproteins

Three patients with IgG myelomatosis and extreme hyponatremia are described. By isoelectric focusing of the M-component it is demonstrated that the subnormal sodium value is most likely explained by a cationic effect of the myeloma globulin.

Prognostic influence of early diagnostic splenectomy in Hodgkin's disease. A long-term follow-up

The influence of early laparotomy with splenectomy on prognosis in patients with Hodgkin's disease who were regarded as having uncertain prognostic indices (all patients except those with lymphocytic predominance and nodular sclerosis stages IA and IIA with right-sided presentation, stage IV disease, splenomegaly or age greater than 65 years) was evaluated in a randomized trial initiated in Jan. 1973. The patients were treated with total nodal irradiation (excluding the splenic and hepatic areas) and 33 of 69 patients were randomized to laparotomy with splenectomy. No significant difference in relapse-free or overall survival was found between the two groups after a median observation time of 85 months. Progressive or recurrent disease was as common in splenectomized as in non-splenectomized patients. Splenectomized patients with splenic tumour involvement fared worse than those without. It is concluded that diagnostic laparotomy with splenectomy is of no benefit in this clinical setting.

No effect of delayed cutaneous hypersensitivity testing (Multitest) on blood lymphocyte counts and functions

The effects of delayed cutaneous hypersensitivity (DCH) testing (Multitest, Institute Mérieux) on lymphocyte counts and functions were studied in seven healthy women. All had normal DCH responses and lymphocyte functions. No influence of the DCH testing on subsequent tests for lymphocyte subpopulations and mitogen- and antigen-induced DNA synthesis was observed. The PPD skin test did not boost or otherwise alter the in vitro lymphocyte response to PPD. It may be concluded that Multitest is a simple way of assessing DCH and that this test does not interfere with repeated in vitro tests of lymphocyte capacity.

Lymphocyte subpopulations in chronic lymphocytic leukemia (CLL). Relation to the activity of the disease

The blood lymphocytosis in CLL is caused mainly by a rise of immunoglobulin (Ig)-bearing leukemic lymphocytes. Most cells carry Fc-receptors, while the percentage with receptors for human complement is very low with the present technique. The leukemic lymphocytes carry only one of the light chain types, which suggests a monoclonal origin. CLL patients with lymphocytes expressing kappa light chains may have a more benign disease than lambda-CLL. T-lymphocyte levels are high during the early course of the disease but decrease with its progression and are low in patients with "active" disease.

Clinical findings and prognostic factors in chronic myeloid leukemias

Ninety-one previously untreated patients with chronic myeloid leukemia admitted to three Stockholm hospitals 1973-1978 were studied. There were 49 men and 42 women with a mean age of 56 years (range 15-93). Sixty-five patients were Philadelphia chromosome (Ph1) positive and 17 were Ph1 negative (mean age 51 and 70 years, respectively). After a mean observation time of 5.2 years, 64 patients had deceased, 45 of them in blast transformation. A low hemoglobin value and a high total blast cell count at diagnosis were associated with a poor prognosis in the Ph1 positive group. Other routine clinical and laboratory variables were of subordinate prognostic importance. Early splenectomy in 15 Ph1 positive patients did not improve survival. Median survival from diagnosis was 38 months for Ph1 positive patients as compared to 12 months for the Ph1 negative group.

Induction treatment with alpha-interferon in multiple myeloma: an interim report from MGCS

A randomized study comparing melphalan/prednisone (M/P) therapy with MP + natural alpha-IFN in untreated patients with multiple myeloma stages II and III started April 1, 1986. By March 1989, 78 patients were evaluable in the MP group and 80 in the MP/IFN group. 48% of the MP patients achieved a response and 66% in the MP/IFN group (p = 0.04). Stage II patients responded better to MP/IFN (76%) than MP alone (47%) (p = 0.02), while no statistically significant difference was noted for stage III patients. 90% of the IgA myelomas responded to MP/IFN and 52% to MP (p = 0.02). Both for IgG and BJ myelomas the response rates of MP/IFN were higher than of MP, although the differences were not statistically significant. The observation period is still short. There was no difference in total survival between the two treatment groups. However, in patients less than or equal to 65 years a tendency to a longer survival was seen for those receiving the IFN combination (p = 0.12).

Extensive nodular infiltration of extra-osseous tissues in human myelomatosis. A case report

The autopsy findings of a woman with myelomatosis diagnosed half a year before her death are described. She had an IgG-lambda myeloma which initially responded to treatment. However, subsequently she developed a condition characterized by massive soft tissue involvement with increased number of plasma cells in peripheral blood. Rounded hard myeloma infiltrates were disseminated through the body, only sparing the adrenal glands and intracranial structures.

Development of a dendritic cell-based vaccine for chronic lymphocytic leukemia

Evidence for the existence of CLL-specific antigens recognized by the immune system can be gathered from the observation that many patients display monoclonal or oligoclonal expansions and skewed repertoire of T cells. In vitro functional studies have shown that tumor-specific T-cells are able to lyse the leukemic cells. Antileukemic cellular immunity may be boosted in vivo using dendritic cell-based immunotherapy. Our preclinical studies provide evidence that DC that had endocytosed apoptotic CLL cells (Apo-DC) were superior to fusion hybrids, tumor lysate or RNA in eliciting antileukemic T-cell responses in vitro. We have validated a method for enriching the small number of monocyte precursors present in the peripheral blood of CLL patients and utilize them for generating individualized, Apo-DC cellular vaccines. In most cases, a minimum of 50 x 10(6) Apo-DC could be generated, beginning with immunomagnetically enriched monocytes from a single leukapheresis product containing at least 1% CD14+ cells. Cryopreservation and thawing did not affect the phenotype or the T cell stimulatory function of Apo-DC. A phase I/II, open label clinical trial examining the feasibility, safety and immunogenicity of Apo-DC vaccination has been initiated. CLL patients receive 10(7) Apo-DC for at least five immunizations and monitored clinically and immunologically for 52 weeks. Three cohorts are accrued stepwise. Cohort I receives Apo-DC alone; Cohort II: Apo-DC+ repeated doses of low-dose GM-CSF; Cohort III: low-dose cyclophosphamide followed by Apo-DC + GM-CSF.

Expression profile of orphan receptor tyrosine kinase (ROR1) and Wilms' tumor gene 1 (WT1) in different subsets of B-cell acute lymphoblastic leukemia

Recent molecular investigations have demonstrated over-expression of a large number of tumor associated antigens (TAAs) in a variety of malignancies. Over-expression of ROR1 gene, a member of the receptor tyrosine kinase family, has recently been reported in B-cell chronic lymphocytic leukemia. Wilms' tumor gene 1 (WT1) has long been known as a universal TAA expressed in a variety of solid and hematopoietic malignancies. In the present study, the expression profile of ROR1 and WT1 was investigated in different immunophenotypic subsets of B-cell acute lymphoblastic leukemia (B-ALL) patients. RT-PCR method was used to determine the ROR1 and WT1 genes expression in bone marrow (BM) and peripheral blood (PB) samples from 51 newly diagnosed Iranian B-ALL patients. Isolated tumor cells from all patients were immunophenotyped by flow cytometry. Based on immunophenotypic results, our B-ALL patients were classified in four differentiation subsets; Pro-B (n = 7), Pre-B I (n = 29), Pre-B II (n = 13) and Immature/mature B-ALL (n = 2). Although ROR1 was over-expressed in more mature subsets (16.7%, 42.9%, 45.5% and 100%, respectively), WT1 was more represented in immature subsets of B-ALL patients (57.1%, 64.3%, 38.5% and 0%, respectively). Comparison of the frequency of ROR1 and WT1 positive samples at each immunophenotypic subtype revealed statistically significant difference only in Pre B I subtype (p = 0.02). Our results suggest that expression of ROR1 and WT1 in B-ALL is associated with the differentiation stage of the leukemic cells.

Idiotype vaccination in patients with myeloma reduced circulating myeloma cells (CMC)

BACKGROUND

Circulating myeloma cells (CMC), exhibiting the same immunoglobulin heavy-chain gene rearrangements as the plasma cells, are part of the myeloma clone. In this study, we evaluated the effect of idiotype (Id) vaccination on CMC.

PATIENTS AND METHODS

Eleven patients were immunized with the autologous Id in combinations with granulocyte-macrophage colony-stimulating factor and interleukin 12, and followed for CMC by quantitative real-time allele-specific PCR. Id-specific T cells were monitored by proliferation assay, enzyme-linked immunospot (interferon-gamma) assay, and quantitative real-time PCR for cytokines. Regulatory T (T(reg)) cells were analyzed by flow cytometry.

RESULTS

CMC were detected in 9 of 11 patients at start of vaccination. In four patients, CMC declined and two had a complete molecular remission. Further two patients had stable levels of CMC during follow-up, while in three patients CMC progressively increased. Six patients had a vaccine-induced Id-specific T-cell response. A significant correlation was observed between reduced/stable levels of CMC and the Id-specific T cells (P < 0.02). The frequency of T(reg) cells was decreased in immune responders, but increased in immune nonresponders (P < 0.05). No significant change in the serum M-protein concentration was, however, observed in any patient.

CONCLUSION

Id vaccination reduced CMC, which correlated with vaccine-induced Id-specific T cells. Further studies are warranted to analyze the clinical significance of CMC and clinical effects of Id vaccination.

Pre-clinical evaluation of a CEA DNA prime/protein boost vaccination strategy against colorectal cancer

In preparation for a clinical trial in patients diagnosed with colorectal cancer, a vaccination strategy targeting the carcinoembryonic antigen (CEA) was evaluated in mice using a GMP-produced plasmid DNA vaccine, CEA66, encoding a truncated form of the tumour-associated antigen, CEA. The GMP-produced CEA DNA vaccine was also evaluated for toxicity. Repeated intradermal administration of the GMP-produced vaccine using a novel needle-free jet injection device (Biojector) induced robust CD4 and CD8 T-cell responses in mice, and did not result in any vaccine-related toxicity. In a heterologous DNA prime/protein boost setting, cellular immune responses were of higher magnitude in animals primed with CEA66 DNA than in animals receiving repeated doses of recombinant CEA protein. These responses were further enhanced if recombinant murine granulocyte-macrophage colony-stimulating factor was given as an adjuvant prior to vaccination. In contrast to repeated administration of recombinant CEA protein as a single modality vaccine, the heterologous CEA66 DNA prime/rCEA boost vaccination strategy resulted in a qualitatively broader immune response, and supports clinical testing of this vaccination regimen in humans.

The challenge of biosimilars

BACKGROUND

The purpose of this report was to review issues associated with the introduction of alternative versions of biosimilars used in the oncology setting.

DESIGN

Data were obtained by searches of MEDLINE, PubMed, references from relevant English-language articles, and guidelines from the European Medicines Agency.

RESULTS

When biosimilars are approved in EU, they will be considered 'comparable' to the reference product, but this does not ensure therapeutic equivalence. Inherent differences between biosimilars may produce dissimilarities in clinical efficacy, safety, and immunogenicity. Switching biosimilars should be considered a change in clinical management. Regulatory guidelines have been established for some biosimilar categories but, because of the limited clinical experience with biosimilars at approval, pharmacovigilance programs will be important to establish clinical databases. Guidelines also provide a mechanism for the extrapolation of clinical indications (approved indications for which the biosimilar has not been studied). This may be of concern where differences in biological activity can result in adverse outcomes or when safety is paramount (e.g. stem cell mobilization in healthy donors). These issues should be addressed in biosimilar labeling.

CONCLUSIONS

Biosimilars should provide cost savings and greater accessibility to biopharmaceuticals. A thorough knowledge surrounding biosimilars will ensure the appropriate use of biopharmaceuticals.

NK-cell and T-cell functions in patients with breast cancer: effects of surgery and adjuvant chemo- and radiotherapy

Breast cancer is globally the most common malignancy in women. Her2-targeted monoclonal antibodies are established treatment modalities, and vaccines are in late-stage clinical testing in patients with breast cancer and known to promote tumour-killing through mechanisms like antibody-dependent cellular cytotoxicity. It is therefore increasingly important to study immunological consequences of conventional treatment strategies. In this study, functional tests and four-colour flow cytometry were used to detect natural killer (NK)-cell functions and receptors as well as T-cell signal transduction molecules and intracellular cytokines in preoperative breast cancer patients, and patients who had received adjuvant radiotherapy or adjuvant combined chemo-radiotherapy as well as in age-matched healthy controls. The absolute number of NK cells, the density of NK receptors as well as in vitro quantitation of functional NK cytotoxicity were significantly higher in preoperative patients than the post-treatments group and controls. A similar pattern was seen with regard to T-cell signalling molecules, and preoperative patients produced significantly higher amounts of cytokines in NK and T cells compared to other groups. The results indicate that functions of NK and T cells are well preserved before surgery but decrease following adjuvant therapy, which may speak in favour of early rather than late use of immunotherapeutic agents such as trastuzumab that may depend on intact immune effector functions.