A clinical trial helps to find a method to treat disease, it’s the only way to test investigational medications. With the strict oversight by Institutional Review Boards, clinical trials provide the U.S. Food and Drug Administration with the scientific information needed to weigh the benefits and risks of a new medication and decide whether it is safe for patients. Early phase, or phase I and phase II study are the first step in testing new medicines that have been developed in the lab. Phase 1 clinical research, usually focuses on ensuring the safety of drugs to use in population rather than how effective it may be as a treatment for a given disease. For selecting the clinical Phase 1 units for large normal, healthy volunteer studies, Sponsors and CROs usually make their selections by determining whether or not a site fulfills a set of standard criteria, which will ultimately determine if the site is equipped to conduct the study at all. To shorten the development timeline of complex molecules, many biopharmaceutical companies are moving toward hybrid, early clinical development (ECD) study models, which require both healthy volunteers and patient populations. Phase 0 trials are the first clinical trials done among people. They aim to learn how a drug is processed in the body and how it affects the body. In these trials, a very small dose of a drug is given to about 10 to 15 people. Clinical trials involving new drugs are commonly classified into four phases. Individual trials may encompass more than one phase. A common example of this is combined phase I/II or phase II/III trials. Therefore, it may be easier to think of early phase studies and late phase studies.[1] The drug-development process will normally proceed through all four phases over many years. If the drug successfully passes through Phases I, II, and III, it will usually be approved by the national regulatory authority for use in the general population. Phase IV are 'post-approval' studies. Phase IIa clinical study evaluate the efficacy and safety in a selected population of patients with the disease or condition to be treated, diagnosed, or prevented. Objectives are focused on dose-response, type of patient, frequency of dosing, or numerous other characteristics of safety and efficacy. Phase IIb trials are well controlled trials to evaluate efficacy and safety in the population with the disease or condition to be treated, diagnosed, or prevented. These clinical trials usually represent the most rigorous demonstration of a medicine's efficacy. Sometimes referred to as pivotal trials. The phases of clinical research are the steps in which scientists do experiments with a health intervention in an attempt to find enough evidence for a process which would be useful as a medical treatment. In the case of pharmaceutical study, the phases start with drug design and drug discovery then proceed on to animal testing. If this is successful, they begin the clinical phase of development by testing for safety in a few human subjects and expand to test in many study participants to determine if the treatment is effective. The purpose of early stage clinical trials is to determine the recommended dose and toxicity profile of an investigational agent or multi?drug combination. Molecularly targeted agents (MTAs) and immunotherapies have distinct toxicities from chemotherapies that are often not dose dependent and can lead to chronic and sometimes unpredictable side effects. Therefore utilizing a dose escalation method that has toxicity based endpoints may not be as appropriate for determination of recommended dose, and alternative parameters such as pharmacokinetic or pharmacodynamic outcomes are potentially appealing options. The Early Phase Clinical Trials Team (EPCTT) has around 20 ongoing studies and accepts several new patient referrals each week. Please see the Early phase clinical research page for details of current early phase trials in the Cambridge area.