RTS,S/AS01E Hypo-immuno-responsiveness Study

Plasmodium Falciparum Clinical Trial

Official title:

A Phase 2b Randomized, Open-label, Controlled, Single Center Study in Plasmodium Falciparum-infected and Uninfected Adults Age 18-55 Years Old in Kenya to Evaluate the Efficacy of the Delayed, Fractional Dose RTS,S/AS01E Malaria Vaccine in Subjects Treated With Artemisinin Combination Therapy Plus Primaquine

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04661579
• Other study ID #: CVIA 078
• Secondary ID: PACTR20200689648
• Status: Completed
• Phase: Phase 2
• Start date: November 6, 2020
• Est. completion date: August 17, 2022

Study information

• Verified date: September 2022
• Source: PATH
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The proposed trial design has been developed to answer several questions related to the nature of RTS,S vaccine efficacy in African adults that may be influenced by concurrent and/or past P. falciparum infection leading to a state of immunologic hypo-responsiveness. The proposed study design encompasses five groups. Three groups (Groups 1, 2, and 3) will be administered RTS,S/AS01E on a 0, 1, 7 month schedule with Dose 3 delivered as a 1/5th fractional dose. Two groups (Groups 4 and 5) will be administered a comparator vaccine on a 0, 1, 7 month schedule.

Description:

PATH and GlaxoSmithKline (GSK) are committed to developing a malaria vaccine to help reduce the burden of malaria disease in children and contribute to malaria elimination. GSK has developed a candidate vaccine against malaria caused by Plasmodium falciparum, RTS,S/AS01E. The vaccine has been shown to be safe in multiple trials and efficacy data in pediatric populations has led to a pilot implementation program in three African countries including Kenya. The RTS,S/AS01E vaccine mechanism of action is presumed to work on the initial sporozoite and liver stages of P. falciparum infection through neutralization of the circumsporozoite (CS) antigen on parasites invading after a mosquito bite in individuals immunized with the RTS,S/AS01E vaccine. In order to inform whether a vaccine such as RTS,S/AS01E may have a future role in malaria elimination, it will be important to establish vaccine efficacy in adults in Sub-Saharan Africa who are reservoirs of parasites and who contribute to ongoing malaria transmission. However, in previous trials, the vaccine has been less effective in adults in endemic regions compared to challenge studies. While the cause of this is likely multi-factorial, there is a degree of immunologic hypo-responsiveness that occurs in endemic regions that may impede the development of a protective immune response following immunization that is presumed to be related to chronic infection. This study postulates that treatment of infection prior to immunization can reset the immune response leading to an improved vaccine efficacy. To evaluate this hypothesis, the study will recruit 5 groups. Groups 1 and 4 will have asymptomatic infection with P. falciparum as measured by a highly sensitive PCR assay (planned assay is an RNA-based polymerase chain reaction (PCR) though the backup utilizes both RNA and DNA PCR, see protocol for details) and will be treated with antimalarial medications prior to immunization with RTS,S/AS01E or the comparator rabies vaccine, respectively, with the primary objective of evaluating the vaccine efficacy of RTS,S/AS01E relative to the rabies vaccine in this context. Groups 2 and 5 will be negative for asymptomatic infection with P. falciparum as measured by a highly sensitive PCR assay and will be treated with antimalarial medications prior to immunization with RTS,S/AS01E or the comparator rabies vaccine, respectively, with the secondary objective of evaluating the vaccine efficacy of RTS,S/AS01 relative to the rabies vaccine in this context. Group 3 will have asymptomatic infection with P. falciparum as measured by a highly sensitive PCR assay but will not be treated with antimalarial medications prior to immunization with the RTS,S/AS01E vaccine; the immunological profile (including anti-CS and cell-mediated immune responses) of this group and groups 1 and 2 will be evaluated as part of secondary and exploratory objectives. Other secondary objectives include safety assessments and other exploratory objectives defined in this protocol. A total of 619 subjects will be enrolled (164 in groups 1 and 4, 128 in groups 2 and 5, and 35 in group 3) over a period of 6 months and will participate in the study for an initial immunization period (vaccine given on 0, 1, and 7 month schedule with the final dose being 1/5 of the dose of the first two immunizations) followed by 6-12 months of follow-up (varying based on the number of events), with the primary and secondary efficacy endpoints of time to first malaria infection by PCR. Total duration expected to be 20.5-26.5 months. Those groups receiving antimalarial medications (1, 2, 3, 4) will receive either dihydroartemisinin-piperaquine or artemether/lumefantrine and low-dose primaquine as described in the protocol.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 620
• Est. completion date: August 17, 2022
• Est. primary completion date: March 18, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 55 Years

Eligibility

Inclusion Criteria:

• Provision of signed or thumb printed and dated informed consent form
• Stated willingness to comply with all study procedures and availability for the duration of the study
• Male or female between 18 and 55 years of age, inclusive
• In good general health as evidenced by medical history and clinical examination before entering the study
• Ability to take oral medication and be willing to adhere to the medication regimen
• For females, she must be of non-childbearing potential or use appropriate measures to prevent pregnancy for 30 days prior to vaccination through 2 months after completion of the vaccine series. Non-childbearing potential means she is surgically sterilized or at least one year post-menopausal. Appropriate measures to prevent pregnancy include abstinence or adequate contraceptive precautions (i.e. intrauterine contraceptive device; oral contraceptives; diaphragm or condom in combination with contraceptive jelly, cream or foam; Norplant or Depo-Provera). Clinical trial site staff will assist with provision of acceptable birth control for study entry and will discuss with volunteer at screening visit.

Exclusion Criteria:

• Planned administration/administration of a vaccine not foreseen by the study protocol from within 30 days before the first dose of study vaccine until 30 days after the last dose of study vaccine.† † In the context of the COVID-19 pandemic, the administration of the COVID-19 vaccine will be allowed as an exception to this exclusion criteria as follows. The study team will work with the participant to attempt to have any COVID-19 vaccine administration occur 30 days or more before or after study vaccinations. When this is not possible, COVID-19 vaccination will be allowed 10 days or more before or after study vaccination. Intervals shorter than 10 days can be allowed on a case-by-case basis in discussion with the sponsor.
• Any prior receipt of any rabies vaccine or experimental malaria vaccine.
• Confirmed or suspected significant immunosuppressive or immunodeficient condition as determined by the investigator, including clinical stage 3 or 4 human immunodeficiency virus (HIV) infection.
• A family history of congenital or hereditary immunodeficiency.
• History of allergic reactions, significant immunoglobulin E (IgE)-mediated events or anaphylaxis to previous immunizations.
• History of any neurologic disorders.
• Acute disease (defined as the presence of a moderate or severe illness with or without fever), including acute malaria, at the time of enrolment. All vaccines can be administered to persons with a minor illness, such as diarrhea or mild upper respiratory infection without fever, i.e. Oral temperature < 37.5°C*. Individuals excluded with acute disease, including acute malaria, can become eligible again after complete recovery of the illness, including appropriate treatment as applicable, and can be rescreened at a later date. *Temperature readings may be taken by site staff either using either oral, axillary, or infrared thermal thermometers during clinic or field visits, while subjects enrolled in the reactogenicity cohort will be supplied with oral thermometers for the purposes of recording their own temperature measurements in the memory aid over 7 days after each vaccination.
• Acute or chronic, clinically significant pulmonary, cardiovascular (including cardiac arrythmias) , hepatic or renal functional abnormality, as determined by medical history, physical examination or laboratory screening tests.
• History of homozygous sickle cell disease (Hgb SS).
• Any clinically significant laboratory abnormalities as determined by the investigator on screening labs.
• History of splenectomy.
• Administration of immunoglobulins, blood transfusions or other blood products within the three months preceding the first dose of study vaccine or planned administration during the study period.
• Pregnant (i.e. a positive pregnancy test) or lactating female during immunization phase of the study (refer to section 2.3 for rationale). If a woman becomes pregnant after all vaccinations are complete, she will not be excluded from the remainder of the study.
• Female planning to become pregnant or planning to discontinue contraceptive precautions during the vaccination phase.
• History of chronic alcohol consumption and/or drug abuse.
• Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose (for corticosteroids, this will mean prednisone, or equivalent, = 0.5 mg/kg/day. Inhaled and topical steroids are allowed).
• Major congenital defects or serious chronic illness.
• Simultaneous participation in any other clinical trial [apart from participation in the Health and Demographics Surveillance System (HDSS) network].
• Any other findings that the investigator feels would increase the risk of having an adverse outcome from participation in the trial.

Related Conditions & MeSH terms

• Malaria
• Plasmodium Falciparum

Intervention

Biological:
• RTS,S/AS01E
Vaccine
• Abhayrab rabies vaccine
Vaccine

Locations

Country	Name	City	State
Kenya	Lucas O Tina	Kisumu	Kisumu County

Sponsors (6)

Lead Sponsor	Collaborator
PATH	DF/Net, FHI Clinical SA Proprietary Limited, GlaxoSmithKline, Kenya Medical Research Institute, US Army Medical Research Directorate-Africa - Walter Reed Army Institute of Research

Country where clinical trial is conducted

Kenya, 

References & Publications (16)

Butler NS, Moebius J, Pewe LL, Traore B, Doumbo OK, Tygrett LT, Waldschmidt TJ, Crompton PD, Harty JT. Therapeutic blockade of PD-L1 and LAG-3 rapidly clears established blood-stage Plasmodium infection. Nat Immunol. 2011 Dec 11;13(2):188-95. doi: 10.1038/ni.2180. — View Citation

Freeman GJ, Sharpe AH. A new therapeutic strategy for malaria: targeting T cell exhaustion. Nat Immunol. 2012 Jan 19;13(2):113-5. doi: 10.1038/ni.2211. — View Citation

Illingworth J, Butler NS, Roetynck S, Mwacharo J, Pierce SK, Bejon P, Crompton PD, Marsh K, Ndungu FM. Chronic exposure to Plasmodium falciparum is associated with phenotypic evidence of B and T cell exhaustion. J Immunol. 2013 Feb 1;190(3):1038-47. doi: 10.4049/jimmunol.1202438. Epub 2012 Dec 21. — View Citation

Keitany GJ, Kim KS, Krishnamurty AT, Hondowicz BD, Hahn WO, Dambrauskas N, Sather DN, Vaughan AM, Kappe SHI, Pepper M. Blood Stage Malaria Disrupts Humoral Immunity to the Pre-erythrocytic Stage Circumsporozoite Protein. Cell Rep. 2016 Dec 20;17(12):3193-3205. doi: 10.1016/j.celrep.2016.11.060. — View Citation

Kester KE, Cummings JF, Ofori-Anyinam O, Ockenhouse CF, Krzych U, Moris P, Schwenk R, Nielsen RA, Debebe Z, Pinelis E, Juompan L, Williams J, Dowler M, Stewart VA, Wirtz RA, Dubois MC, Lievens M, Cohen J, Ballou WR, Heppner DG Jr; RTS,S Vaccine Evaluation Group. Randomized, double-blind, phase 2a trial of falciparum malaria vaccines RTS,S/AS01B and RTS,S/AS02A in malaria-naive adults: safety, efficacy, and immunologic associates of protection. J Infect Dis. 2009 Aug 1;200(3):337-46. doi: 10.1086/600120. — View Citation

Moorthy VS, Ballou WR. Immunological mechanisms underlying protection mediated by RTS,S: a review of the available data. Malar J. 2009 Dec 30;8:312. doi: 10.1186/1475-2875-8-312. Review. — View Citation

Nielsen CM, Vekemans J, Lievens M, Kester KE, Regules JA, Ockenhouse CF. RTS,S malaria vaccine efficacy and immunogenicity during Plasmodium falciparum challenge is associated with HLA genotype. Vaccine. 2018 Mar 14;36(12):1637-1642. doi: 10.1016/j.vaccine.2018.01.069. Epub 2018 Feb 10. — View Citation

Polhemus ME, Remich SA, Ogutu BR, Waitumbi JN, Otieno L, Apollo S, Cummings JF, Kester KE, Ockenhouse CF, Stewart A, Ofori-Anyinam O, Ramboer I, Cahill CP, Lievens M, Dubois MC, Demoitie MA, Leach A, Cohen J, Ballou WR, Heppner DG Jr. Evaluation of RTS,S/AS02A and RTS,S/AS01B in adults in a high malaria transmission area. PLoS One. 2009 Jul 31;4(7):e6465. doi: 10.1371/journal.pone.0006465. — View Citation

Regules JA, Cicatelli SB, Bennett JW, Paolino KM, Twomey PS, Moon JE, Kathcart AK, Hauns KD, Komisar JL, Qabar AN, Davidson SA, Dutta S, Griffith ME, Magee CD, Wojnarski M, Livezey JR, Kress AT, Waterman PE, Jongert E, Wille-Reece U, Volkmuth W, Emerling D, Robinson WH, Lievens M, Morelle D, Lee CK, Yassin-Rajkumar B, Weltzin R, Cohen J, Paris RM, Waters NC, Birkett AJ, Kaslow DC, Ballou WR, Ockenhouse CF, Vekemans J. Fractional Third and Fourth Dose of RTS,S/AS01 Malaria Candidate Vaccine: A Phase 2a Controlled Human Malaria Parasite Infection and Immunogenicity Study. J Infect Dis. 2016 Sep 1;214(5):762-71. doi: 10.1093/infdis/jiw237. Epub 2016 Jun 13. — View Citation

RTS,S Clinical Trials Partnership, Agnandji ST, Lell B, Fernandes JF, Abossolo BP, Methogo BG, Kabwende AL, Adegnika AA, Mordmüller B, Issifou S, Kremsner PG, Sacarlal J, Aide P, Lanaspa M, Aponte JJ, Machevo S, Acacio S, Bulo H, Sigauque B, Macete E, Alonso P, Abdulla S, Salim N, Minja R, Mpina M, Ahmed S, Ali AM, Mtoro AT, Hamad AS, Mutani P, Tanner M, Tinto H, D'Alessandro U, Sorgho H, Valea I, Bihoun B, Guiraud I, Kaboré B, Sombié O, Guiguemdé RT, Ouédraogo JB, Hamel MJ, Kariuki S, Oneko M, Odero C, Otieno K, Awino N, McMorrow M, Muturi-Kioi V, Laserson KF, Slutsker L, Otieno W, Otieno L, Otsyula N, Gondi S, Otieno A, Owira V, Oguk E, Odongo G, Woods JB, Ogutu B, Njuguna P, Chilengi R, Akoo P, Kerubo C, Maingi C, Lang T, Olotu A, Bejon P, Marsh K, Mwambingu G, Owusu-Agyei S, Asante KP, Osei-Kwakye K, Boahen O, Dosoo D, Asante I, Adjei G, Kwara E, Chandramohan D, Greenwood B, Lusingu J, Gesase S, Malabeja A, Abdul O, Mahende C, Liheluka E, Malle L, Lemnge M, Theander TG, Drakeley C, Ansong D, Agbenyega T, Adjei S, Boateng HO, Rettig T, Bawa J, Sylverken J, Sambian D, Sarfo A, Agyekum A, Martinson F, Hoffman I, Mvalo T, Kamthunzi P, Nkomo R, Tembo T, Tegha G, Tsidya M, Kilembe J, Chawinga C, Ballou WR, Cohen J, Guerra Y, Jongert E, Lapierre D, Leach A, Lievens M, Ofori-Anyinam O, Olivier A, Vekemans J, Carter T, Kaslow D, Leboulleux D, Loucq C, Radford A, Savarese B, Schellenberg D, Sillman M, Vansadia P. A phase 3 trial of RTS,S/AS01 malaria vaccine in African infants. N Engl J Med. 2012 Dec 13;367(24):2284-95. doi: 10.1056/NEJMoa1208394. Epub 2012 Nov 9. — View Citation

RTS,S Clinical Trials Partnership, Agnandji ST, Lell B, Soulanoudjingar SS, Fernandes JF, Abossolo BP, Conzelmann C, Methogo BG, Doucka Y, Flamen A, Mordmüller B, Issifou S, Kremsner PG, Sacarlal J, Aide P, Lanaspa M, Aponte JJ, Nhamuave A, Quelhas D, Bassat Q, Mandjate S, Macete E, Alonso P, Abdulla S, Salim N, Juma O, Shomari M, Shubis K, Machera F, Hamad AS, Minja R, Mtoro A, Sykes A, Ahmed S, Urassa AM, Ali AM, Mwangoka G, Tanner M, Tinto H, D'Alessandro U, Sorgho H, Valea I, Tahita MC, Kaboré W, Ouédraogo S, Sandrine Y, Guiguemdé RT, Ouédraogo JB, Hamel MJ, Kariuki S, Odero C, Oneko M, Otieno K, Awino N, Omoto J, Williamson J, Muturi-Kioi V, Laserson KF, Slutsker L, Otieno W, Otieno L, Nekoye O, Gondi S, Otieno A, Ogutu B, Wasuna R, Owira V, Jones D, Onyango AA, Njuguna P, Chilengi R, Akoo P, Kerubo C, Gitaka J, Maingi C, Lang T, Olotu A, Tsofa B, Bejon P, Peshu N, Marsh K, Owusu-Agyei S, Asante KP, Osei-Kwakye K, Boahen O, Ayamba S, Kayan K, Owusu-Ofori R, Dosoo D, Asante I, Adjei G, Adjei G, Chandramohan D, Greenwood B, Lusingu J, Gesase S, Malabeja A, Abdul O, Kilavo H, Mahende C, Liheluka E, Lemnge M, Theander T, Drakeley C, Ansong D, Agbenyega T, Adjei S, Boateng HO, Rettig T, Bawa J, Sylverken J, Sambian D, Agyekum A, Owusu L, Martinson F, Hoffman I, Mvalo T, Kamthunzi P, Nkomo R, Msika A, Jumbe A, Chome N, Nyakuipa D, Chintedza J, Ballou WR, Bruls M, Cohen J, Guerra Y, Jongert E, Lapierre D, Leach A, Lievens M, Ofori-Anyinam O, Vekemans J, Carter T, Leboulleux D, Loucq C, Radford A, Savarese B, Schellenberg D, Sillman M, Vansadia P. First results of phase 3 trial of RTS,S/AS01 malaria vaccine in African children. N Engl J Med. 2011 Nov 17;365(20):1863-75. doi: 10.1056/NEJMoa1102287. Epub 2011 Oct 18. — View Citation

RTS,S Clinical Trials Partnership. Efficacy and safety of RTS,S/AS01 malaria vaccine with or without a booster dose in infants and children in Africa: final results of a phase 3, individually randomised, controlled trial. Lancet. 2015 Jul 4;386(9988):31-45. doi: 10.1016/S0140-6736(15)60721-8. Epub 2015 Apr 23. Erratum in: Lancet. 2015 Jul 4;386(9988):30. — View Citation

RTS,S Clinical Trials Partnership. Efficacy and safety of the RTS,S/AS01 malaria vaccine during 18 months after vaccination: a phase 3 randomized, controlled trial in children and young infants at 11 African sites. PLoS Med. 2014 Jul 29;11(7):e1001685. doi: 10.1371/journal.pmed.1001685. eCollection 2014 Jul. — View Citation

Weiss GE, Crompton PD, Li S, Walsh LA, Moir S, Traore B, Kayentao K, Ongoiba A, Doumbo OK, Pierce SK. Atypical memory B cells are greatly expanded in individuals living in a malaria-endemic area. J Immunol. 2009 Aug 1;183(3):2176-82. doi: 10.4049/jimmunol.0901297. Epub 2009 Jul 10. — View Citation

Weiss GE, Traore B, Kayentao K, Ongoiba A, Doumbo S, Doumtabe D, Kone Y, Dia S, Guindo A, Traore A, Huang CY, Miura K, Mircetic M, Li S, Baughman A, Narum DL, Miller LH, Doumbo OK, Pierce SK, Crompton PD. The Plasmodium falciparum-specific human memory B cell compartment expands gradually with repeated malaria infections. PLoS Pathog. 2010 May 20;6(5):e1000912. doi: 10.1371/journal.ppat.1000912. — View Citation

Wykes MN, Horne-Debets JM, Leow CY, Karunarathne DS. Malaria drives T cells to exhaustion. Front Microbiol. 2014 May 27;5:249. doi: 10.3389/fmicb.2014.00249. eCollection 2014. Review. — View Citation

* Note: There are 16 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Exploratory: Anti-rabies antibodies	Anti-rabies antibodies at specified timepoints in a subset of subjects in Groups 4 and 5.	Specified timepoints up to 32 weeks.
Other	Exploratory: Cell-mediated immune responses	Cell-mediated immune responses in subjects administered RTS,S/AS01E (Groups 1, 2, and 3) will be descriptive in nature.	Specified timepoints up to 32 weeks.
Other	Exploratory: RNA transcriptional responses	RNA transcriptional responses for all subjects in Groups 1 - 5.	Specified timepoints up to 32 weeks.
Other	Exploratory: Human Leukocyte Antigen (HLA) typing	HLA typing in subjects administered RTS,S/AS01E (Groups 1, 2, and 3).	Up to 53 weeks.
Other	Exploratory: Malaria Cross-sectional prevalence at end of study	Cross-sectional malaria PCR/DBS at Study Termination visit in Groups 1 - 5.	Results determined time period between approximately week 46 and up to approximately week 77.
Primary	Vaccine Efficacy: Malaria infection by PCR in Groups 1 and 4	The time to first malaria infection by PCR after completing vaccination in Groups 1 and 4.	Start of active detection of infection phase at approximately week 30 until up to 77 weeks.
Secondary	Vaccine Efficacy: Malaria infection by PCR in Groups 2 and 5	The time to first malaria infection by PCR after completing vaccination in Groups 2 and 5.	Start of active detection of infection phase at approximately week 30 until up to 77 weeks.
Secondary	Safety parameters: Incidence of Serious Adverse Events (SAEs) as assessed by meeting SAE definition per protocol	Frequency count and proportion of subjects reporting serious adverse events (SAEs) during the whole study period. SAEs are defined as adverse events which: Results in death,; Is life-threatening,; Results in disability/incapacity,; Requires hospitalization or prolongation of existing hospitalization,; Results in disability/incapacity.; Results in a congenital anomaly and / or birth defect.	From Dose 1 to study conclusion.
Secondary	Safety parameters: Incidence of solicited local and systemic adverse events as assessed by definition of events per protocol	Frequency count and proportion of subjects reporting solicited local and systemic adverse events within 7 days after each vaccination.; Local (injection site) adverse events are defined as: Pain at injection site; Swelling at injection site; Systemic adverse events are defined as: Fever (temperature >37.5 C); Headache; Gastrointestinal problems; Fatigue; Muscle ache	Within 7 days after each vaccination.
Secondary	Safety parameters: Incidence of unsolicited adverse events as assessed by definition of events per protocol	Frequency count and proportion of subjects reporting unsolicited adverse events within 28 days after each vaccination. An adverse event is defined as any untoward medical occurrence in a study participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product, or temporally associated with a study procedure.	Within 28 days after each vaccination.
Secondary	Immunogenicity: Anti-circumsporozoite (CS) antibody	Anti-circumsporozoite (CS) antibody levels and avidity at specified time points.	Specific timepoints up to 53 weeks.
Secondary	Immunogenicity: Hepatitis B surface antibody (HBsAb)	Hepatitis B surface antibody (HBsAb) levels at specified time points.	Specific timepoints up to 53 weeks.