Infographics of Modern Therapeutics

Introduction

The purpose of this report is to provide highlights from two posts involving infographics of modern therapeutics, since these posts were originally only listed under their months of posting, but not indicating their titles. These were as follows:

The graphs in these two posts are in addition to extensive infographics on the progression of 40 therapeutic classes, across 14 therapeutic categories, included in Progression of Modern Therapeutics, issued January 2016, and in a more extended reporting on 16 therapeutic classes, summarized in List of 16 Posts on Individual Therapeutic Classes, issued January 2018.

Methodology

The data used in both of these two above referenced posts are originally from Progression of Modern Therapeutics, which covers 40 therapeutic classes from 14 therapeutic categories, and which includes a detailed description of the methodology and definitions used in this project. Note the following definitions used throughout:

  • Modern therapeutics – refers to those new drug approvals belonging to a given pharmacologic class that were first approved in the 1970’s to 1980’s timeframe and going forward, as further defined in Progression of Modern Therapeutics.
  • Pharmacologic class – refers typically to a biologic target-based or mechanism of action-related classification, but in some instances involves a chemical classification, or a mix of the two.
  • Therapeutic class – refers to new drug approvals for a given disease or indication, independent of pharmacologic class.
  • Therapeutic category – refers to approved therapeutics in a given anatomical organ or system.
  • Length of registration interest – refers to the time interval between the dates of the first and the latest new drug approval within a given pharmacologic class.

Number of Pharmacologic Classes per Therapeutic Classes

The number of pharmacologic classes per individual therapeutic classes for new drug approvals is shown in the graph below, in a descending order, for 38 of the 40 therapeutic classes covered in Progression of Modern Therapeutics. 

Click here for a larger graph. Note the wide range in the number of pharmacologic classes per therapeutic classes, ranging from 11 and 9 for Type-2 Diabetes and Multiple Sclerosis, respectively, and 8 each for Rheumatoid Arthritis and Melanoma, to 1 each for Idiopathic Thrombocytopenic Purpura and Systemic Lupus Erythematosus, and several therapeutic classes with 2 each, including Alzheimer’s Disease and Schizophrenia. Note that the mean and median for the number of pharmacologic classes per individual therapeutic classes (N=38) are 4.3 and 4.0, respectively.

New Drug Approvals per Therapeutic Classes

The number of new drug approvals for 38 of the 40 therapeutic classes covered in Progression of Modern Therapeutics is shown in the graph below, in descending order. 

Click here for a larger graph. Note the wide variability in the number of new drug approvals for the different therapeutic classes, ranging from 44 for Hypertension, 28 for HIV-1/AIDS, 27 for Type-2 Diabetes and 23 for Schizophrenia, to 1 for Systemic Lupus Erythematosus, 2 each for Idiopathic Thrombocytopenic Purpura and Idiopathic Pulmonary Fibrosis (both orphan indications) and 3 for Fibromyalgia. Note that the mean and median for the number of new drug approvals per individual therapeutic classes (N=38) are 11.5 and 9.5, respectively.

Selected Snapshots from Noteworthy Patterns in Registration Avivities

Below are two selected snapshots based on data in Progression of Modern Therapeutics, each illustrating a specific pattern in registration activities of modern therapeutics:

Snapshot #1: Two therapeutic classes showing two key pharmacologic classes with no overlaps in registration activities, i.e., H2 Receptor Antagonists and Proton Pump Inhibitors for Acid Reflux and Ulcer Disease, and Benzodiazepines and Non-benzodiazepines for Insomnia. Both examples show an abrupt switch in new drug introductions from older pharmacologic classes to newer pharmacologic classes. For a larger graph click here.

no overlap

Snapshot #2: Two therapeutic classes showing two key pharmacologic classes with overlaps in registration activities, i.e., Corticosteroids and Beta-2 Adrenergic Agonists for Asthma, and SSRI’s and SNRI’s for Depression. Both examples show concurrent new drug introductions for two dominant or somewhat similar pharmacologic classes or mechanisms of action. For a larger graph click here.

overlap

Length of Registration Interest

Perusal of the graphs for 40 therapeutic classes in Progression of Modern Therapeutics also illustrates a wide variability in the length of registration interest, i.e., the time interval between the dates of the first and the latest new drug approval within a given pharmacologic class (shown on the right hand side of the graphs). Of the more than 180 pharmacologic classes covered, it is if interest to note that 16 classes have lengths of registration interest longer than 25 years, e.g., Beta-Blockers for Hypertension (40.1 decimal years) and Typical and Atypical Antipsychotics for Schizophrenia (26.9 and 25.9 decimal years, respectively), and that lengths between 10 and 20 years are quite common for established pharmacologic classes, e.g., TNF Inhibitors for Rheumatoid Arthritis (10.5 decimal years) and PDE-5 Inhibitors for Erectile Dysfunction (14.1 decimal years).

Comments

The infographics of modern therapeutics presented in this report involve examples from two previous posts, but are highlighted here, since the original posts were only listed under their months of posting (February 2016 and June 2016), but not indicating their titles. 

The graphs and texts illustrate wide variability in new drug approvals among the different pharmacologic classes and therapeutic classes. This involves both the number of pharmacologic classes per individual therapeutic classes, and the number of new drug approvals per individual therapeutic classes. For example, the number of pharmacologic classes per individual therapeutic classes ranged from 11 (Type-2 Diabetes) to 1 (Systemic Lupus Erythematosus), and the number of new drug approvals per individual therapeutic classes ranged from 44 (Hypertension) to 1 (Systemic Lupus Erythematosus). Also noteworthy is that 16 pharmacologic classes of the more than 180 covered have lengths of registration interest longer than a quarter of a century; also note the most common interval of lengths of registration interest is 10-20 years (31 pharmacologic classes), for lengths longer than 5 years.

Note these graphs only involve new drug approvals, and do not include generics, new formulations, or new trademarks of previously approved chemical entities. Also note these graphs and texts are based on data available in early 2016; there may have been a few new drug approvals in some of the covered therapeutic classes since then, but not so much as to alter the key conclusions presented.

It is tempting to speculate what might be the reasons underlying such wide variabilities in the number of pharmacologic classes per therapeutic classes, in the total number of new drug approvals per therapeutic classes, and in the relatively long periods of registration interest for numerous pharmacologic classes, but that will be left to another time. Public discussion on these important topics, however, is very important, since at a high level, these are likely to relate to how society in general – including the academic research community, the regulatory agencies, the pharmaceutical R&D community, and patient and disease organizations – attempt to address varying degrees of scientific knowledge about disease etiology and pathophysiology, levels of research funding, commercial assessment, and different levels of unmet medical need.