Imiquimod Trial (Part 2)

Objectives

1. To determine the antibody response rates to subcutaneous vaccination with influenza vaccine in patients with untreated stage A chronic lymphocytic leukaemia.
2. To determine whether subsequent application of Imiquimod cream to the vaccination site will enhance the antibody response.
3. To vaccinate patients’ spouses to control for the subcutaneous route and the older age group to which patients are likely to belong
4. To save samples of blood for subsequent investigation of T cell responses.

Trial Design

This is a randomized phase II study comparing antibody responses to two influenza vaccination protocols in patients with untreated stage A CLL.

Eligibility

All patients with CLL stage A (see BCSH guidelines3) who have not been treated with corticosteroids, chemotherapy or monoclonal antibodies.

Exclusion Criteria

1. Patients with other malignancies
2. Patients receiving corticosteroids or other immunosuppressive drugs
3. Patients who have received vaccination against influenza in the past 6 months
4. Patients who have had an allergic reaction to a flu shot in the past, or have an allergy to eggs or who previously developed Guillain-Barré syndrome within 6 weeks of getting a flu shot
5. Patients failing to give informed consent.

List of Recommended Investigations

1. Prior to vaccination: FBC, urea and electrolytes, liver functions studies, serum immunoglobulins.
2. Prior to vaccination: in patients who have not previously be tested for prognostic factors: IgVH mutations, CD38, ZAP-70, FISH for del11q and del 17p.
3. Prior to vaccination: serum sample for antibodies to influenza haemagglutinins.
4. Prior to vaccination: 50mls whole blood for future T cells studies.
5. 28 days post vaccination: serum sample for antibodies to influenza haemagglutinins
6. 14 days post vaccination: 50 ml whole blood for future T cells studies.


How Investigations will be carried out

Routine blood counts and biochemistry will be carried out at the laboratories of the Royal Bournemouth Hospital. Samples for T cells testing will be separated and frozen down for future study. We expect to receive future funding to carry out these investigations in house. These will comprise Elispot tests to investigate specific release of cytokines from T cells.

Samples for haemagglutination inhibition titres against influenza H1N1, H2N3, and B antigens will be batched and frozen, and tested under contract by the Central Public Health Laboratory Specialist & Reference Microbiology Division, 61, Colindale Avenue, London NW9 5HT.

Vaccination procedure


Vaccination will use the 2006--07 trivalent influenza vaccine virus strains: A/New Caledonia/20/1999 (H1N1)-like, A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like antigens. For the A/Wisconsin/67/2005 (H3N2)-like antigen, the vaccine may contain instead the antigenically equivalent A/Hiroshima/52/2005 virus; for the B/Malaysia/2506/2004-like antigen, the vaccine may contain the antigenically equivalent B/Ohio/1/2005 virus.

0.5 ml of the vaccine will be administered subcutaneously under the skin over the deltoid muscle. A two cm diameter circle will be drawn on the skin around the injection site in water insoluble ink

Those patients randomized to receive Imiquimod will be instructed to rub a small amount Imiquimod cream into the skin within the circle, starting on the day after the vaccination and continuing daily for five days. Imiquimod comes in a sachet that can be sealed by a paper clip, and should be kept refrigerated between applications. The cream should be left on the skin for 8 hours and then washed off with soap and water.

Patients’ spouses will be offered vaccination and if they consent they will receive subcutaneous vaccination in the same way as the patients, but they will not receive application of the Imiquimod cream.

Side effects

Imiquimod is licensed for application to genital skin. It can produce local erythema with itching and pain with prolonged use. A single application is likely to produce nothing more than mild local inflammation.

Influenza vaccines are produced in the allantoic cavity of chick embryos and are therefore contraindicated in those with allergy to eggs. Otherwise, mild local inflammation and mild ‘flu like symptoms are the most likely side effects.

Source of patients for study

There are currently just over 100 untreated stage A CLL patients attending out-patient clinics at the Royal Bournemouth Hospital who have had blood tested for prognostic markers. It is from this group of patients that subjects for the study will initially be recruited. If insufficient patients can be recruited from the study from this cohort, patients who have not had prognostic markers studied will be invited to participate. Prognostic markers will be determined for this group.


Randomization

Randomization will be achieved by opening a series of numbered sealed envelopes kept in the office of the Haematology secretariat. The envelopes will contain a card on which is written A or B; computer generated random numbers will determine which, A for even numbers, B for odd numbers.

Statistical Calculations

Assuming that the control group has a 15% response to vaccination, an improvement to a 50% response rate would be worthwhile. To have an 90% chance of detecting such an improvement at the p=5% level would require 34 patients in each arm.

Evaluation

Response to vaccination is defined as a fourfold increase in haemagglutination inhibition titre. A haemagglutination inhibition titre of 100 is regarded as protective. Results will be compared between the two arms of the study. Responses to vaccination will be compared with several other factors, including age, sex, presence or absence of palpable lymph nodes and spleen, serum immunoglobulin levels, prognostic factors and length of time the patient has been diagnosed for.

Ethical Considerations

Prior to starting the study, the protocol must be approved by Local Research and Ethical Committee (LREC). Amendments to the protocol may only be made with approval by the Principal Investigator, and will be subject to review by the LREC. Written documentation of the Ethics Committee approval must be received before the amendment can be incorporated into the protocol.

The patient will be given time to discuss his/her participation in the study with the Investigator concerned and family members as well as his or her GP. Before the patient is entered into the study, the patient’s written consent must be obtained. A copy will be retained by the patient and the original filed in the Investigator's Trial File unless otherwise agreed.

The patient may refuse treatment either before or at any time during the study. Refusal to participate will involve no penalty or loss of benefits to which the patient is otherwise entitled.

The study will be carried out in accordance with the Declaration of Helsinki.

Suspected Unexpected Serious Adverse Events (SUSARs)

An adverse reaction is ‘serious’ if it:
a. results in death;
b. is life-threatening;
c. requires hospitalization or prolongation of existing hospitalization;
d. results in persistent or significant disability or incapacity;
e. consists of a congenital anomaly or birth defect.
An adverse reaction is ‘unexpected’ if its nature and severity are not consistent with the information about the medicinal product in question set out:
a. in the case of a product with a marketing authorization, in the summary of product characteristics for that product;
b. in the case of any other investigational medicinal product, in the investigator’s brochure relating to the trial in question.

A SUSAR which is fatal or life-threatening must be reported to the LREC as soon as possible and in any event within seven days after the sponsor became aware of the event. Any additional information must be reported within eight days of sending the first report.
A SUSAR which is not fatal or life-threatening must be reported to the LREC as soon as possible and in any event within 15 days after the sponsor became aware of the event.

Publication policy

Results of this study will be submitted for publication.

The Imiquimod Trial

Respiratory infections are one of the commonest causes of death in patients with chronic lymphocytic leukemia (CLL). Immunodeficiency is one of the most important features of the disease. Severe hypogammaglobulinemia is a common complication, and even patients with early disease have an impaired ability to produce an antibody response to a novel antigen [1]. Even with a recall antigen like tetanus toxoid antibody responses were only seen in stage A patients in 4/14 patients and not at all in more advanced stage patients [2].

Although patients with CLL are advised to receive annual vaccination against influenza [3], the production of a protective antibody response is extremely uncertain. There have been three recent studies of attempts to increase responses by giving a second booster vaccination shortly after the initial dose. In the first [4] the response rate went from 14% to 35%; in the second [5] from 0% to 5%; and in the third [6] which included patients with other haematological malignancies, the response rose from 18% to 22%. In real life it is likely that the most beneficial effect of influenza vaccination for CLL patients is herd immunity, with spouses, relatives and friends being vaccinated

The cause of the immunodeficiency in CLL is not known. Although it is worse in more advanced patients, it precedes treatment and it precedes the development of hypogammaglobulinemia. It occurs very early in the disease, long before the lymphoid system is overwhelmed by infiltration with CLL cells.

One possibility is a defect in antigen presentation. The most important antigen presenting cells are dendritic cells. In CLL the circulating dendritic cell is severely defective and unable to stimulate an effective T cell response [7]. This defect seems to be due to the presence of the CLL cells, possible operating via one of the many cytokines (including IL-6, IL-10, VEGF and M-CSF) that CLL cells produce [8]. Nevertheless, when stimulated by an appropriate cytokine milieu it is possible stimulate and activate dendritic cells derived from the peripheral blood of CLL patients [9].

A new group of immune stimulants, the imidazoquinolones [10], act by binding to Toll receptor 7 on the surface of macrophages, inducing the secretion of the pro-inflammatory cytokines IFN-gamma, TNF-alpha, and IL-12. This local cytokine milieu favours the development of activated dendritic cells. One of the imidazoquinolones, Imiquimod, is licensed for the treatment of genital and perianal warts and for basal cell carcinoma, and is available as a cream to apply to the skin. The drug has also being investigated as an adjuvant in cancer vaccine studies where preliminary experiments demonstrate its capacity for activating dendritic cells and markedly enhancing the production of cytotoxic T lymphocytes [11, 12].

We propose to investigate the possibility that the application of Imiquimod to the site of a subcutaneous vaccination might enhance the immune response to influenza vaccine in patients with chronic lymphocytic leukaemia. In order, to see an effect of Imiquimod it will be necessary to give the vaccine subcutaneously rather than intramuscularly. Influenza vaccines are licensed for this mode of administration and although it is normally reserved for patients with bleeding disorders, it is equally efficacious. However, to control for the different route of administration and for the fact that CLL patients mostly belong to an older generation and might give a poorer response to vaccination because of this, we propose to offer subcutaneous influenza vaccination to patients’ spouses, measuring responses in a similar way. This would, in any case, be part of routine management to take advantage of herd immunity.

References
1. Hamblin TJ, Verrier Jones J, Peacock DB. The immune response to x 174 in man: iv primary and secondary antibody production in patients with chronic lymphatic leukaemia. Clinical and Experimental Immunology 1975; 21:101 108.
2. Sinisalo M, Aittoniemi J, Oivanen P, Olander R-M, Vilpo J. Response to vaccination against different types of antigens in patients with chronic lymphocytic leukaemia. Brit J Haematol 2001; 114:107-110.
3. Oscier D, Fegan C, Hillmen P et al. Guidelines on the management of chronic lymphocytic leukaemia. Brit J Haematol 2004; 125:294-317.
4. Jurlander J, de Nully Brown P, Skov PS et al. Improved vaccination response during ranitidine treatment, and increased plasma histamine concentrations, in patients with B cell chronic lymphocytic leukemia. Leukemia 1995; 9:1902-1909.
5. van der Velden AMT, Mulder AHL, Hartkamp A, Diepersloot RJA, van Velzen-Blad H, Biesma DH. Influenza virus vaccination and booster in B cell chronic lymphocytic leukaemia patients. Eur J Int Med 2001; 12:420-424.
6. Ljungman P, Nahi H, Linde A. Vaccination of patients with haematological malignancies with one or two doses of influenza vaccine: a randomized study. Brit J Haematol 2005; 130:96-98.
7. Orsini E, Guarina A, Chiaretti S, Mauro FR, Foa R. The circulating dendritic cell compartment in patients with chronic lymphocytic leukemia is severely defective and unable to stimulate an effective T-cell response. Cancer Res 2003; 63:4497-4506.
8. Orsini E, Pasquale A, Maggio R et al. Phenotypic and functional chatacterization of monocyte-derived dendritic cells in chronic lymphocytic leukaemia patients: influence of neoplastic CD19 cells in vivo and in vitro. Brit J Haematol 2004; 125:720-728.
9. Messmer D, Telusma G, Wasil T et al. Dendritic cells from chronic lymphocytic leukemia patients are normal regardless of Ig V gene mutation status. J Mol Med 2004; 10:7-12.
10. Stanley MA. Imiquimod and the imidazoquiniolones: mechanism of action and therapeutic potential. Clin Exp Dermatol 2002; 27:571-577.
11. Rechsteiner G, Warger T, Osterloh P, Schild H, Radsak MP. Cutting edge: priming of CTL by transcutaneous peptide immunization with Imiquamod. J Immunol 2005; 174:2476-2480.
12. Warger T, Osterloh P, Rechsteiner G et al. Synergistic activation of dendritic cells by combined Toll-like receptor ligation induces superior CTL responses in vivo. Blood. 2006; 108:544-550.

Imiquimod Trial 3

Over the past couple of days I have posted details of the Imiquimod trial that we intend conducting in Bournemouth this autumn.

The idea for this trial was Chaya Venkat's and it seemed to me a very good one. Rather than try another combination of chemotherapeutic agents that would make patient's immunity worse, we decided to attack one of the problems that patients have difficulties with, namely respiratory infections. Why patients with CLL are immunodeficient is not clear, but one possiblity is that their dendritic cells don't work properly. Imiquimod is drug that is already licensed that works by stimulating dendritic cells.

There have been problems in getting the study going, and teh main one is in securing a quantity of flu vaccine. Apparently there is a national shortage in the UK. then there are the regulatory authorities. Wow! There are so many perverse incentives to not bothering with trials and just going ahead without evidence.

Anyway we hope to start work soon. We have had generous funding from CLL Topics Inc. and we hope also from the UK CLL Support Association.

Jab and Dab

Readers will know all about the problem of infection in CLL. Although there are many treatments that make the lymph nodes go away and the white count come down, although both hemoglobin and platelet counts can be restored to normal, although the marrow can be cleared of CLL cells, nothing makes the immune system normal.

Everybody agrees that it is worth being vaccinated against common infections including influenza, but tests show that responses to vaccines are poor. For this reason and inspired by an idea of Chaya's we are recruiting to a trial which attempts to enhance the response to flu vaccine.

The Jab and Dab trial is being sponsored by CLL Topics and details are laid out on Chaya's website. Briefly it involves the use of imiquimod, a cream used to treat rather indolent skin cancers, to be rubbed on the skin after the flue jab. Imiquimod activates one of the Toll-like receptors, TR7, which stimulates the immune response. The trial will be run by Dr Helen McCarthy in Bournemouth. The trial protocol and patient information sheet are available on line.

Dr McCarthy is one of the hematologists who replaced me when I retired from Bournemouth. She has a long standing interest in CLL and spent a year working with Dr Keating and Dr Wierda at MD Anderson. While there she discovered that high levels of AID could be detected in patients with unmutated IgVH genes.

Vaccination for the coming winter.

We are entering the flu vaccination period and I have been asked for advice for CLL patients.

The first thing to say is that CLL patients are very poor at responding to vaccines. If you have late disease and especially if you have been treated by a purine analog (Fludarabine, Cladribine or Pentastatin) of with Campath, it is very unlikely that you will respond to any vaccine. Your best hope of protection is to avoid infection - make sure that family members are vaccinated and avoid crowds (especially unvaccinated children). don't shake hands, don't share a common communion cup, avoid kissing unvaccinated people and wash your hands frequently. By all means get vaccinated but don't be too disappointed if it doesn't work.

As far as I can tell WHO advice (which dates from April 2009) still recommends that you have the seasonal flu vaccine.

The components recommended for the 2009/10 northern hemisphere influenza vaccine are as follows;
• A/Brisbane/59/2007 (H1N1)-like virus;
• A/Brisbane/10/2007 (H3N2)-like virus;
• B/Brisbane/60/2008-like virus.

This is the same as the 2008 vaccine, which many of you will have had, so having it this year boosts what is left of last year's immunity.

But since April 2009 we have had swine flu as a pandemic. This is also an H1N1 virus, but serologically different from the Brisbane virus present in the seasonal vaccine. It may be that it has similarities to the 1957-8 Asian flu pandemic since individuals over 65 do not seem to be suffering so severely from the new strain. Swine flu vaccines are being evaluated and should be available this month. The question is whether you will need both. The answer is we don't know. The recommendation, at least from the British Department of Health seems to be that one should have both, but I am not certain that experts have really addressed the issue. It really depends as to whether both strains of the virus will be infecting people this winter. From past experience it is the new strain that predominates.

Generally I advise CLL patients to have two flu shots at 6 week intervals and to take a big dose of ranitidine (300mg twice a day) for 90 days starting with the first injection. Whether this will work is still not established, but there are supporting papers for the idea. The imiquimod trial has not yet reported. I am not sure how to advise on what would potentially be 4 injections (2 seasonal, 2 swine).

Advice on pneumovax is very difficult. Response in CLL patients is virtually zero. This is because it is a polysaccharide vaccine to which CLL patients respond extremely poorly. In infants Prevnar 7 gives a better response (being a conjugated vaccine) and there is every reason to suspect that it would give a better response in CLL patients. However, it is designed for the 7 strains of pneumococcus that are present in 80% of infant pneumonias and may not cover as wide a range as the 23 strains in pneumovax. A Prevnar 13 is due out shortly, and in Europe a vaccine against 10 strains, Synflorix, is available. Again end stage patients and those who have had fludarabine are very unlikely to respond.

I'm sorry to be so uncertain, but that is the lie of the land at present. I will update this as time passes.