Malaria: life cycle

"Humanity has but 3 great enemies: fever, famine and war; of these by far the greatest, by far the most terrible is Fever." William Osler.

Malaria
Malaria is a protozoan disease transmitted by the bite of infected Anopheles mosquitoes. It is the most important parasitic diseases of humans, with transmission in 103 countries and causing between 1 and 3 million deaths each year. Malaria remains today a heavy burden on tropical communities, a threat to non endemic countries, and a danger to travelers.

LIFE CYCLE
Four species of the genus Plasmodium cause nearly all malaria infections in humans. These are P. vivax, P. ovale, P. malariae, P. falciparum.

1. Human infection begins when a female anopheles mosquito inoculates plasmodium sporozoites from its salivary glands during a blood meal. 
2. These microscopic motile forms of the malaria parasite are carried rapidly via the blood stream to the liver, where they invade hepatic parenchymal cells and begin a period of asexual reproduction. They areknown as hypnozoites. By this amplification process (known as intra hepatic or preerythocytic schizogony or merogony)
3. A single sporozoite then produces 10,000 to >30,000 daughter merozoites. 
4. The swollen liver cell eventually bursts, discharging motile merozoites into the bloodstream.
5. These then invade the red blood cells and multiply 6-20 fold every 48 to 72 hours.
6. When parasite densities reach near about 50 per microlitre of blood, the symptomatic stage of infection begins.
7. In P . vivax and P . ovale infections , a proportion of the hypnozoites lie dormant and do not divide. They can lie dormant from a period of 3 weeks to a year or longer before they begin asexual reproduction. These dormant hypnozoites are the cause of relapses that characterize infection with these 2 species.
8. After merozoites enter bloodstream they rapidly invade erythrocytes and become trophozoites.
9. Attachment to erythrocyte is through the a special receptor on the erythrocyte. For P . vivax , this receptor is related to Duffy blood group antigen Fya and Fyb . Therefore west Africans who carry the Duffy fyfy phenotype are resistant to P . vivax malaria.
10. During early stage of development, the ring stage of 4 parasitic species appear appear similar under microscopy. As trophozoites enlarge, species specific characteristics become apparent. By the end of 48 hour intraerythocytic life cycle (72 hours for P . malariae ), the parasite has consumed nearly all haemoglobin and grown to fill most of the RED and is now called a schizont.
11. Multiple nuclear divisions take place known as schizogony or merogony and the RBC ruptures to release 6-30 daughter merozoites. These further invade more RBC
12. After a series of asexual cycles in case of P . falciparum or immediately after release from the liver, in case of the other 3 species , some of the parasites develop into sexual forms called gametocytes that can transmit malaria.
13. After these gametocytes are ingested by a female anopheles mosquito,  the male female forms form a zygote in the insects midgut. The zygote matures into a ookinete,  which penetrators and encysts in the mosquitos gut wall . the resulting oocyte enlarges until it burns to release  a large number of motile sporozoites.

Writing a Good Clinical Study Report

At the end of a clinical trial it is important to analyse data in detail and present it well. Writing a report is a regulatory requirement and only on submitting the report complete with proceedings of the trials and results on analysis of data gathered during the trial will the next step in the development plan of a drug be granted.

Steps to writing a good Clinical Study Report include a good knowledge of widely accepted contents of the report. ICH has a whole guidance devoted to writing a clinical study report (E3). It is a detailed document on contents of the report.

Each section  will be discussed below:

Definition of a Clinical Study Report (CSR) : CSR is a-
1. Integrated full report of an individual study I.e., where in clinical and statistical descriptions, presentations and analyses are integrated into a single report.
2.Report of any drug which can be for therapeutic, diagnostic or prophylactic use
3 . Report of a study conducted in patients
4. Report in which Tables and figures are incorporated in the main text of the report or at end of text while the appendices of the report contain protocol, sample CRF, investigator related information, information related to test drug/investigational product, technical statistical document, related publication, patient data listings,  technical statistical details such as derivations , computations, analyses and computer output.

The report should provide a clear explanation of how the critical design features of the study were chosen and enough information on plan, method and conduct of the study so that there is no ambiguity on how the study was carried out.

The report and its appendices should provide enough  individual patient data,including demographic data,  baseline data and details of analytical methods used so as  to enable replication of result if authorities wish to do so.

Structure and Content of the report:
As per ICH format, there are 16 sections in total of the study report. The 16 sections are mentioned below in the order described in the guidance.

1. TITLE PAGE
2. SYNOPSIS
3. TABLE OF CONTENTS
4. LIST OF ABBREVIATIONS
5. ETHICS
6. INVESTIGATORS AND STUDY ADMINISTRATIVE STRUCTURE
7. INTRODUCTION
8. STUDY OBJECTIVES
9. INVESTIGATIONAL PLAN
10. STUDY PATIENTS
11. EFFICACY EVALUATIONS
12. SAFETY EVALUATIONS
13. DISCUSSION AND OVERALL CONCLUSION
14. TABLE, FIGURES AND GRAPHS REFERRED TO BUT NOT INCLUDED IN TEXT
15. REFERENCE LIST
16. APPENDICES

The details of each section is presented below:

1. TITLE PAGE:
The title page should contain
I. Study title
II. Name of the test drug/investigational product
III. Indication studied
IV. If not apparent from the title then a brief description of the study design
V. Name of the sponsor
VI. Protocol identification ( code or number)
VII. Study initiation date(first patient enrolled), date of early study termination, study completion date(last patient completed)
VIII. Name and affiliation of principal or coordinating investigator or sponsors responsible medical officer
IX. Name of sponsors signatory
X. Statement indicating that the study was performed in compliance with Good Clinical Practice, including archiving of essential documents.
XI. Date of report.

2. SYNOPSIS
The synopsis should summarise the study and should generally
Be limited to 3 pages. The synopsis should include numerical data to represent results and not just text and p values. Basically a clear understanding of the CSR should be possible from the synopsis.

3 . TABLE OF CONTENTS
It should have details of each section and the page numbers at which these sections are located

4. LIST OF ABBREVIATIONS AND DEFINITIONS OF TERMS
A list of abbreviations and unusual terms should be provided in this section . Abbreviated terms should be spelled out and the abbreviations indicated I  the parenthesis in the first appearence in the text.

5. ETHICS
Ethical conduct of a trial is an important aspect of GCP and this section is devoted to giving evidence on the same. Under this section details of ethics committee involved in the trial, ethical principals followed during the trial and freely given informed
consent are mentioned.

6. INVESTIGATOR AND STUDY ADMINISTRATIVE STRUCTURE
Details of the team at site I.e., the principal Investigator,
coordinating investigator; details of steering committee , CRO's,  statistician, monitoring, central laboratory , author of the report should be mentioned.

7. INTRODUCTION
 The introduction should contain a brief statement generally of one page which should clearly mention the place the study in the Context of the development programme. It should mention the rationale,  aims, target population, treatment, duration, primary endpoints of the trial. Any guidance referred to during predation of the protocol or any meetings / discussion with the regulatory authority with respect to protocol development can be mentioned here.

8. STUDY OBJECTIVES
The overall purpose of the study should be mentioned here.

9. INVESTIGATIONAL PLAN
 9.1 Overall study design and plan should be described briefly and clearly by using charts or diagrams.
The information to be provided is:
- Treatment studied
- Population and number of patients studied
- level and method of blinding and masking
- kind of control used
- method of assignment to treatment
-sequence and duration of all study periods
- preferably display of the design graphically with a flow chart

9.2.  Discussion of study design, including choice of control groups
Blinding, randomization and choice of control should be discussed. Merits and demerits to be mentioned

9.3. Selection of Study Population
Inclusion, exclusion and withdrawal criteria should be mentioned

9.4 Treatments
Treatments administered (dose, route, method of administration), identity of the investigation product (batch number, formulation,  strength) , if more than one batch is used then the patients receiving each batch should be identified , source of investigational product and comparator should be provided, method of resupply in case of limited shelf lives,method of assigning to different treatment groups, selection of doses in the study, selection and timings of dose for each patient, blinding, prior and concomitant medication, treatment compliance.

9.5 Efficacy and Safety variables

9.6 Data quality assurance

9.7 statistical methods used in the protocol and determination of sample size.

9.8 changes in conduct of the study or planned analysis.

10. STUDY PATIENTS
Disposition of patients, protocol deviations

11. EFFICACY EVALUATIONS
Data sets analysed, demographic and other baseline characteristics,  measurement of treatment compliance,  efficacy results and tabulations of individual patient data.

12. SAFETY EVALUATIONS
Safety related data to be analysed at 3 levels. First , the extent of exposure; second, more common adverse events; third serious adverse events and other significant adverse events should be identified.

13. DISCUSSION AND OVERALL CONCLUSION
The efficacy and safety results and the relationship of risks and benefits should be briefly summarised and discussed.

14. TABLES FIGURES AND GRAPHS REFERRED TO BUT NOT INCLUDED IN TEXT - self explanatory

15. REFERENCE LIST
A list of articles referred to in the text should be provided.

16. APPENDICES
16.1
I.  Protocol and protocol amendments
II. Sample CRF
III. List of IRBs/IECs
IV. List of investigators including CVs
V. Signature of investigators or sponsors responsible medical expert
VI. Listing of patient receiving test drug/ investigational products

VII. Randomization schemes and codes
VIII. Audit Certificates
IX. Documentation of statistical methods
X. Documentation of inter laboratory standardisation methods and quality assurance
XI. Publications based on the study
XII. Important publications referenced in the report

16.2
PATIENT DATA LIST ING

16.3
CRF

16.4
Individual patient data listings

Deep Vein Thrombosis

Deep venous thr:
mboembolism can be divided into 2 types (VTE)
1. Deep venous thrombosis (DVT)
2. Pulmonary embolism (PE)

DVT occurs due to coagulation of blood (formation of a thrombus) in one of the deep veins. DVT generally affects the veins in legs or arms. More common is lower extremity DVT. This results in pain and swelling in the affected limb.

If DVT is not treated,  the throbs can get fragmented and can move up the arteries in the Lung. This can be potentially life threatening.

Diagnosis:
Gold standard is Venography
Alternatively Ultrasound examination may also be done.

Pathophysiology:
Virchow triad - venous stasis, activation of blood coagulation and vein damage. These 3 factors are responsible for development of DVT.

Venous stasis can be a result of any factor that slows or obstructs blood flow. This leads to increased viscosity of blood and microthrombi formation. Due to obstruction of blood , the microthrombi are not washed away and may increase in size.

Etiology
Can be due to acquired or congenital factors
Acquired factors can be those which result in prolonged immobilisation for e.g hospitalizations after surgery, bedridden patients, stroke, paraplegia or transcontinental flights.
Congenital factors such as enzyme deficiency or mutation, anatomic defects can lead to DVT.

Risk factors
1. History of previous VTE
2. Cancer
3. Age older than 75 years
4. Acute infectious disease
5. Obesity
6. Orthopedic surgery
7 . immobility for longer than 3 days
8. Pregnancy
9. Burns
10. Oral contraceptives

Treatment
Goal of therapy is to prevent PE and prevent post thrombotic syndrome.

I. Mainstay is anticoagulation. This therapy treats 90% of patients.
Agents used:
1. Heparin derivatives: unfractionated and low molecular weight heparin(LMWH). Act by inhibiting activated factor X. Bleeding complication is mainly attributed to higher molecular fragments and lower with LMWH
 2. Factor Xa Inhibitors
A. Fondaparinux - direct inhibitor of factor X . administered as a once daily subcutaneous injection.
Monitoring of aPTT and PT not required.
3. Rivaroxaban - oral factor Xa inhibitor approved for treatment of DVT and PE
4. Apixaban - approved both for treatment as well as prophylaxis of DVT and PE.
5. Dabigatran - approved for treatment of DVT and PE and prevention of PE in stroke patients


Treatment for first episode should be for atleast 3 months and for recurrent episodes for a year.

Complications of therapy: hemorrhagic complications are yhe most common adverse events of anticoagulation therapy. Bleeding can occur in 3-10% people on 3-6 month anticoagulation therapy.

Emerging agents: razaxaban,  idraparinux,  bivalirudin,  lepirudin,  ximelagatran


II. Thrombolysis

III. Surgical thrombectomy

Prophylaxis of DVT
- Pneumatic compression
- aspirin
- warfarin
- heparins: unfractionated and LMWH( enoxaparin,  deltaparin , nadroparin, tinzaparin,  ardeparin)
- Rivaroxaban

-Apixaban

Burn : Classification and Treatment

Burns are classified into 3 types:
1. Superficial burns (1st degree burns) - these are burns which are limited to the epidermis
2 Partial thickness burns (2nd degree burns)- this is subdivided into 2 types
2 a. Superficial partial thickness burns - these involve all of the epidermis and the upper layers of the dermis
2 .b Deep partial thickness burns - these involve the whole of the epidermis and dermis
3. Deep partial thickness burns (3 rd degree burns)- these involve all layers of the skin and subcutaneous fat

Treatment:
1st degree burns can be treated with lotions, honey, aloevera or topical antimicrobial.
2nd degree burns can be treated with either a topical antibiotic or an occlusive dressing.
3rd degree burns generally require a skin graft.

Cleaning  of burn wounds should be done with sterile water. Ice should not be applied to a burn wound as it may cause further damage due to hypoyhermia. Wound healing is expedited in moist environment therefore occlusive dressing is preferred. Silver sulphadiazine is the preferred topical antibiotic.

inhaled insulin: Afrezza

Insulin is typically available as subcutaneous or intravenous insulin for the treatment of diabetes.
First inhaled insulin which was approved was Exubera.

Exubera is a powdered form of recombinant human insulin, delivered through an inhaler into the lungs where it is absorbed.  However a longer acting basal insulin by injection.

Exubera was however discontinued by Pfizer in 2007 due to poor sales as it was found that  though inhaled insulin appears to be as effective, but no better than injected short-acting insulin,  the additional cost was so much more that was unlikely to be cost-effective.

At the time of Exubera's discontinuation, several other companies were pursuing inhaled insulininsulin. Afrezza which belongs to Mankind pharma received FDA approval in June 2014

FDC Policy in India: Kokate Report

A FDC is a combination of two or more actives in a fixed ratio. Co packaged products are also treated as FDCs.

The need of Fixed dose combinations (FDCs) is increasingly being felt as they improve adherence to treatment or the combination of actives works synergistically.

The Kokate Report which is an Indian policy guidance on  approval of FDCS by CDSCO was released in June 2013.

As per the guidance for the approval of an FDC the following are a must:
1. Therapeutic rationalisation
2. Careful justification
3. Clinically relevant

The application for marketing authorization may comprise of
1. Original data
2. Data from literature
3. Hybrid: both original data and data from literature (most common)

However, quality data set will always be totally original

The SCOPE of the guidance is applicable to
1. import,
2. manufacture or
3. marketing approval of the FDC in India.


FDCs are classified into 4 main categories:

1. One or more active ingredients of the FDC is a new drug not approved india.

In this case FDC will be considered as an NCE and all requirements pertaining to an NCE will have to be fulfilled. Therefore a

Requirements will be as follows:
I. For phase I CT
1 .Data on  animal pharmacology and Animal toxicology
2.protocol of phase I trial.
3. IB
4 . ICD
5. Copy of ethics committee approval letters
6. Registration number of the ethics committee
7. CRF
8. Undertaking by the Investigator and CO
9. Undertaking by the sponsor

I I. For phase 2 CT
1. Summary of the non clinical data with references
2 . results of the repeat dose systemic toxicity studies to support the duration of proposed human exposure.
3. Study report of Phase I study.
4. Phase 2 study protocol
5. IB,ICD, CRF, Copy of EC approvals, registration numbers of the ECs,
6. Investigator and sponsor undertaking.

I I I. Phase  3 CTs
1. Summary of non clinical data
2. Study reports of phase 1 and phase 2 studies,
3. Protocol, IB, ICD, CRF of phase 3 trial, EC approvals and registration numbers.
4. Undertaking by sponsor and investigators.
5. Prescribing information of the drug circulated in other countries , if any.

IV. Phase IV TRIALS
1 . drug approval details and conditions for marketing
2. Proposed protocol, IB, ICD, CRF,EC approval letters,registration number of ECs
3. Undertaking by investigator and sponsor
4. Prescribing information, post marketing data of the FDC, clinical data generated post grant of marketing authorization.

Certain exceptions to this rule include:

1 a. If the individual APIs of the proposdd FDC are already marketed in another country which has a regulatory system comparable to india.
1b. The FDC is marketed in india however one of the API is not approved for the indication or in the strength as in the proposed FDC.
1c. FDC is already marketed in india but a change in ratio of the active ingredients is sought in the proposed FDC.

Principles of ICH GCP

Clinical research is mainly conducted world over on good clinical practice principles as outlined in the ICH GCP Guidance.

This is a tripartite guidance accepted by USA, Europe and Japan.

There are 13 principles outlined in the E6 guidance of ICH-GCP.ICH GCP is the international conference on harmonisation of technical requirements for registration of pharmaceutical products.The 13 principles are as follows:1. Clinical research based on ethical principles: Clinical trials should be conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki, and that are consistent with GCP and the applicable regulatory requirement(s).2. Risk benefit analysis: Before a trial is initiated, foreseeable risks and inconveniences should be weighed against the anticipated benefit for the individual trial subject and society. A trial should be initiated and continued only if the anticipated benefits justify the risks.3. Rights , safety and well being of subjects: The rights, safety, and well-being of the trial subjects are the most important considerations and should prevail over interests of science and society4. Adequate data to support study: The available nonclinical and clinical information on an investigational product should be adequate to support the proposed clinical trial.5. Clinical trials should be scientifically sound, and described in a clear, detailed protocol.6. Compliance to protocol:  trial should be conducted in compliance with the protocol that has received prior institutional review board (IRB)/independent ethics committee (IEC) approval/favourable opinion7.Qualified physician: The medical care given to, and medical decisions made on behalf of, subjects should always be the responsibility of a qualified physician or, when appropriate, of a qualified dentist.8. Qualification of individuals involved: Each individual involved in conducting a trial should be qualified by education, training, and experience to perform his or her respective task(s).9. Informed consent: Freely given informed consent should be obtained from every subject prior to clinical trial participation10. Data collection: All clinical trial information should be recorded, handled, and stored in a way that allows its accurate reporting, interpretation and verification.11. Confedentiality of records:The confidentiality of records that could identify subjects should be protected, respecting the privacy and confidentiality rules in accordance with the applicable regulatory requirement(s).12. GMP: Investigational products should be manufactured, handled, and stored in accordance with applicable good manufacturing practice (GMP). They should be used in accordance with the approved protocol. 13. Quality assurance: Systems with procedures that assure the quality of every aspect of the trial should be implemented.