Clinical Research Center and Phase 1 Unit

Convex Clinical Research Center was designed and built to address all the needs of the clinical research process. With over 40 experienced clinical investigators our Clinical research center with phase 1 unit offer an excellent approach to early phase research. Convex phase 1 unit is designed and built to address all the needs of the clinical research process and to ensure quality medical care and safety standards. Open 24/7, it is custom-designed facility and it is focused on pharmacokinetic studies on healthy volunteers. Our dedicated team of pharmacologists and early phase clinical research team perform phase 1 studies on patient population with a spectrum of diseases. Before each study is initiated we ensure all protocol requirements are followed and Convex Phase 1 unit is in compliance with the appropriate guidelines and regulations.

Phase 1 Unit

Phase 1 Unit

The Phase 1 unit, centrally located in Sofia city, allowing Convex dedicated staff to progress within the process of recruitment and retention of volunteers and to constantly develop a database of study subjects for multiple types of clinical trials. Our phase 1unit is constructed in a way to facilitate phase 1 researchers to conduct studies for a new drug or treatment in a small group of people and to evaluate its safety, determine a safe dosage range and/or identify side effects. Our expertise includes First-In-Man (FIM) studies, escalating dose studies, interaction studies, PK/PD studies, bioequivalence studies, and early phase studies. Convex clinical research institution with Phase 1 unit is designed and equipped to ensure compliance and safety.

  • 15 beds with IV infusion capability
  • 11 clinical examination rooms
  • 24-hour Emergency Care team on standby for immediate medical attention
  • 24-hour clinical investigational team available
  • Clinical safety laboratory
  • Sample processing room
  • Temperature / access-controlled drug storage area
  • Access-controlled sample storage room
  • Comfortable lounge
  • Dining area
  • Archiving facility
  • Server room
  • Office space/ CRAs space
  • 2 Waiting rooms
  • 2 Receptions
  • Emergency equipment and medications
  • 2 ultrasounds
  • X-ray, MRI, CT scan access
  • vital signs monitor
  • ECGs/Holter monitor, spirometers
  • Multiplate analyzer
  • Stadiometer, weighing scale, body thermometers
  • 5 Freezers -80/-70/-20/ 4 refrigerators
  • And others
Phase 1 Clinical Research Units

Pioneering Clinical Excellence: Leading Healthy Volunteer Clinical Studies in Phase 1 Research Site in Eastern Europe

Convex clinical research site with dedicated phase I unit proudly conducted more than 250 clinical studies on healthy volunteers, for the past 33 years contributing significantly to the advancement of healthcare through our dedication to excellence and innovation. Our diverse portfolio showcases our adaptability and expertise

We specialize in pioneering Single Ascending Dose/Multiple Ascending Dose (SAD/MAD) studies, where we evaluate the safety and tolerability of new compounds in healthy volunteers, laying the foundation for future drug development. Our proficiency extends to Bioequivalence studies, where we compare generic and brand-name medications, ensuring their efficacy and interchangeability. In Bioavailability studies, we explore the pathways of drug absorption, guiding the formulation process for optimal therapeutic outcomes. Additionally, our commitment to holistic health is showcased through our in-depth investigations into food supplements and herbals, exploring their impact on wellness. Moreover, we excel in evaluating the safety and effectiveness of various medical devices, contributing significantly to the evolution of cutting-edge healthcare technologies.

First-in-Man (Single Ascending Dose/Multiple Ascending Dose (SAD/MAD) clinical studies in Eastern European Phase I Clinical Research Site

Single Ascending Dose/Multiple Ascending Dose (SAD/MAD) Studies: These studies involve the administration of escalating doses of a new drug to assess safety, tolerability, and pharmacokinetics in healthy volunteers. Our experienced team meticulously conducts these trials, ensuring accurate data collection and analysis.

Bioequivalence studies/ Bioavailability studies (BE/BA) Clinical Studies on Healthy Volunteers

Bioequivalence Studies: Comparing the efficacy and safety of generic and brand-name medications is crucial in healthcare. Our bioequivalence studies evaluate different formulations of drugs to guarantee their equivalence, enabling healthcare providers and patients to make informed choices.

Bioavailability Studies: Understanding how drugs are absorbed, metabolized, and excreted by the body is essential for drug development. Our bioavailability studies assess the rate and extent of drug absorption, helping pharmaceutical companies optimize formulations for maximum effectiveness.

Transdermal Drug Delivery Clinical Studies on Healthy Volunteers in Phase I Site

We specialize in conducting groundbreaking Transdermal Drug Delivery Clinical Studies, exploring innovative ways to administer medications through the skin. Transdermal drug delivery offers a non-invasive approach, allowing medications to be absorbed directly into the bloodstream through the skin, bypassing the gastrointestinal system. This method not only enhances patient comfort but also ensures precise and consistent drug release, leading to improved therapeutic outcomes.

Our experienced team of researchers and clinicians meticulously design and execute these studies, evaluating the efficacy, safety, and patient acceptance of transdermal drug delivery systems. We collaborate closely with pharmaceutical companies, guiding them in the development and optimization of transdermal patches, gels, creams, and other delivery methods. Through rigorous protocols and advanced technologies, we assess the absorption rates, bioavailability, and overall effectiveness of these innovative drug delivery systems

Medical Device Studies in Eastern European Investigational site

Innovation in medical devices is transforming healthcare delivery. Our team specializes in evaluating various medical devices, ensuring they meet stringent safety standards and offer optimal performance. From usability testing to performance evaluations, we contribute to the development of cutting-edge medical technologies.

Food Supplements and Herbals Clinical trials with Healthy volunteers and Patients

Studies on Food Supplements and Herbals: In an era where natural supplements play a significant role in health and wellness, our research delves into the impact of food supplements and herbals on the human body. We conduct comprehensive studies to evaluate their efficacy, safety, and potential benefits, providing valuable insights for consumers and manufacturers alike.

Vaccine Studies in Eastern Europe – a Dedicated Research Partner for Healthy Volunteers Studies

These trials are pivotal in ensuring the safety, efficacy, and long-term impact of vaccines that protect us from various infectious diseases. Our dedicated team of clinical investigators and researchers and healthcare professionals meticulously design and conduct vaccine clinical trials, adhering to the highest ethical and regulatory standards. By collaborating with pharmaceutical companies and research organizations, we evaluate the safety profiles, immune responses, and overall effectiveness of vaccines across diverse populations.

Specializing in Clinical Studies on Healthy Volunteers. Research site in Eastern Europe.

We specialize in clinical studies involving healthy volunteers, ensuring that our research is conducted with precision, ethical integrity, and a focus on participant safety. Our team of experts is dedicated to advancing medical knowledge, contributing to the development of safer treatments, and improving healthcare outcomes. By partnering with us, you can be confident that your research is conducted with the highest level of expertise and care. We have large pool of healthy volunteers who are ready to participate into our medical research programs.

Quality Assurance in our clinical research studies:

Quality is at the core of our operations. We adhere to rigorous standards and protocols, employing the latest technologies and methodologies to guarantee the integrity and reliability of our findings. Our commitment to upholding the highest ethical standards ensures the safety and well-being of the volunteers who participate in our studies, making their trust and confidence our top priority.

Through these varied studies, we remain steadfast in our mission to drive innovation, enhance patient care, and shape the future of healthcare practices.

The safety and comfort of our clinical trial participants are of utmost importance

Convex research center provides emergency care specialists as well as specialized emergency medical transportation during treatment period for the save of our participants. In case of need, the clinical center maintains contract with an university hospital for unhindered and smooth emergency room accommodation and high-quality medical service. We have created a relaxed and comfortable environment where our study subjects successfully complete their participation and meet new friends and medical professionals they could rely on in future. A comfortable and clean environment, as well as maintaining of high-tech equipment, restful furniture and fun activities are elements for a full-comfort stay of our participants. Normally, our participants relax during their participation and gather pleasant stay memories. This approach allows us to complete our clinical projects without complications and constantly expand our healthy volunteer database on a monthly basis. The food during study treatment periods is of essential importance. By exceeding our participants expectation, we successfully manage to maintain nutritional quality and quantity from a dietetic perspective and in compliance to all protocol requirements. To achieve all that we collaborate with a specialized catering company that meets all medical requirements and authorized by the Ministry of Health in Bulgaria.
Phase 1 Studies

Phase 1 Unit Europe

Before every Phase I trial, as well as assessing risk and justifying that assessment, there must be a strategy for ensuring that any risk is minimised throughout the trial. Should potential investigators be concerned about the level of risk of the IMP, the sponsor must give them access to people with responsibility for the relevant pre-clinical work. Also, the sponsor’s physician should liaise with the investigator. If investigators still have concerns about pre-clinical data, they should consult an independent adviser.  Assessment and management of risks should be documented (e.g., through a risk management plan). The strategy for managing risk should consider all aspects of the trial. The majority of Phase I clinical trials use healthy subjects. This approach has the advantage of speed of recruitment and ease of scheduling cohorts of subjects throughout the study. It also removes potential confounding factors such as concomitant medication and disease pathology when reviewing adverse event and PK data. Healthy subjects may generally tolerate and facilities match the level of risk of the IMP. Investigators must not take on trials of an IMP for which they do not have adequate experience or training. The PI and unit staff responsible for the care of subjects in FIH clinical trials should always be appropriately qualified and experienced. The PI for a FIH trial has to meet specific training and experience requirements. The sponsor should ensure that the investigator knows enough about the agent, its target, mechanism of action and potential adverse events to be in a position to manage the informed consent process with the subject, and to make informed clinical judgments during the study. The investigator must also understand the intricacies of executing FIH trials, including the potential need to adjust doses during the study as human data become available. The investigator must assess the risk of harm, by reviewing the protocol, investigator’s brochure, IMP dossier, CTA application and, any relevant medical and scientific literature. In addition, the investigator must weigh the foreseeable risks and inconveniences against the expected benefits for the individual subject, and for future subjects with the target disease. Finally, the investigator must explain and justify any risks in the information leaflet for trial subjects and in the EC application. The sponsor should conduct a site evaluation to consider the site’s capabilities to meet the specific demands of a particular protocol such as appropriate medical governance, drug-specific biomarker methodologies or sample acquisition/ analysis, the ability to recruit study participants FIH clinical trials of IMPs with identified factors of risk should be conducted in research units with sufficient expertise and know-how. However, this does not negate the importance of a site-evaluation by sponsor staff. Site assessment by the sponsor staff should include, but not be limited to:

  • evaluation of the qualification, training and experience of the site staff (in particular the PI) with FIH clinical trials and the ability to carry out appropriate safety monitoring
  • the site’s experience with IMPs of all levels of risk
  • the site’s process and experience with dose escalation decisions
  • the site’s facilities and ability for stabilising individuals in an acute emergency
  • the site’s ability to conduct resuscitation, the proximity to hospital, the access to Intensive Care Services, and ready availability of Intensive Care Unit facilities.

In FIH clinical trials where there is a predictable risk of certain types of severe adverse reaction, the sponsor should specifically address risk mitigation in the protocol, which should include considerations for treatment of such reactions. The sponsor and research site should ensure that any specific antidotes will be readily available, where they exist, as well as a clear plan of supportive treatment, including the pre-arranged contingency availability of intensive care facilities or specialty consultation. The research site should assess the study-specific requirements for clinical cover and ensure that an appropriate level of staffing, with medical doctors during and after dosing, will be present. For the FIH trials of IMPs other than those factors of risk, the sponsor should consider similar factors as previously discussed, on a case-by-case basis. As a minimum, the sponsor must assess facilities, training and experience of personnel, and the evidence that unit medical staff are appropriately qualified and trained in handling emergency situations. Finally, it is critical that subjects taking part in FIH clinical trials have not been recently exposed to other investigational products.

Convex CRC is a clinical research center with a built-in phase I unit in which we have the capabilities and expertise to conduct clinical trials in early phases. Convex center for early drug development is focused on the conduct of single-center clinical trials (Phase 1 Studies) on healthy volunteers and patient populations:

  • Phase I clinical studies (Dose ascending/Dose tolerability)
  • Pharmacokinetic and Pharmacodynamic studies (PK/PD)
  • Bioequivalence and Bioavailability studies (BE/BA)
  • Dose Response
  • IV Infusion Studies
  • Age/Gender Studies
  • Drug-Drug Interaction Studies
  • Drug-Food Interaction Studies
  • Metabolic Balance Studies
  • Patient Population Studies 
  • Safety and Efficacy studies
  • Food Supplements studies
  • Medical devices studies
  • Vaccines studies

Our phase I unit is designed specifically for early-phase clinical studies, following the guidelines of the UK Medicines and Healthcare Products Regulatory Agency and the ICH-GCP. The stationary part of the unit can accommodate 15 subjects for overnight stay. All essential facilities for storing study drugs, maintaining and storing study documentation, managing biological samples and handling emergency situations are available inside the unit. Specimens are seamlessly transferred for analysis to preferred bioanalytical lab or safety lab of your choice. Recruitment of subjects is facilitated significantly by the fact that the Clinical Research Center is strategically situated within a large metropolitan area, with access to population of over 2,5 million people. Our strongly developed network of referring General Practitioners and the availability of proactive recruitment specialists also brings a great benefit to successful recruiting achievments.


  • DDI
  • Food effect studies
  • Thorough QT (TQT) / cardiac safety
  • Bioavailability studies
  • Bioequivalence studies
  • Biosimilar product
  • Proof-of-concept trials
  • Pharmacodynamics / biomarkers


  • High-quality design and execution of clinical trials
  • Preparation of clinical protocols, informed consent forms and key study documents
  • Operational oversight by a highly experienced study team
  • 24-hour medical monitoring and physician investigator availability
  • Clinical data verification
  • Administrative and Regulatory Support
  • Electronic data capture
  • Human sample analysis
  • PK-PD analysis
  • Preparation of clinical study report


  • Purpose-built Phase I unit
  • 15 beds/5 infusion chairs
  • Experienced team of 26 physicians and principal investigators
  • Database of >2500 healthy volunteers 
  • RA inspected facility
  • Shorten CTA approval timelines
  • Global Pharma/Biotech Sponsor partnership           

General Information of phase I clinical trials:

Phase I is usually the first time a new medical intervention is tried in people. Phase I trials may be offered to healthy volunteers or patients with disease that has not responded to standard treatment. The number of patients in a phase I trial is usually small – from 10 to 80 – and unlike later phase trials all patients on a phase I trial will receive the active intervention. Phase I trials are usually of brief duration – several weeks to a few months – and often take place at specialist hospitals.

Phase I trials are not always ‘first-time-in-human’ trials. ‘Secondary’ phase I trials evaluate new dosing schedules or combination therapies using medical interventions. These phase I trials may also assess drug toxicity or device function in different patient populations, for example children who were not studied before. Some phase I trials are designed to have ‘on/off’ periods where the intervention is actively used in the patient for a period and then not used for a prescribed period to evaluate its effects. This type of trial is called a crossover trial and is applicable only for some types of intervention.

To minimize the risk to patients, the dose or setting of the intervention being tested starts very low. The first dose is based on laboratory tests and the effects seen in animals. If none of the patients have any side effects the dose/setting is adjusted for the next patients, who will be given a higher dose. The dose/setting will continue to be increased in this way until some people do get side effects. When the side effects become unsafe the dose/setting is not increased any further and the clinical trial team knows what the maximum tolerated dose/setting is.

Sometimes a phase I trial is offered to a patient as a ‘last hope’ because no other treatment has worked and a doctor has no other standard treatment to offer. It is also natural for patients to want to try anything available and for their doctors to want to offer something else, especially if the patient wants to undergo more treatment.

Early phase clinical trialDedicated clinical research institution specialized in the conduct of early phase clinical trials focused on healthy volunteers and specific patient population clinical studies.
State of the art equipmentThe research institution is equipped with all necessary equipment for the proper conduct of FIM, BE/BA, PK/PD studies.
Research quality serviceWe do make conscious decisions to commit to research requirements needed to build a sustainable research site. We constantly invest in quality systems to deliver quality data for the ultimate outcome of safe and effective new medical therapies. We commit daily to providing optimal care for study patients, following the regulations and self-regulating with the intent of quality improvement.
Clinical subject data baseConstantly increasing our study subject database consisting of large number of healthy volunteers and specific patient population. We are proud to make our study participants stay involved through-out the entire course of a studies as well as relaxed & happy.
Related clinical research servicesConvex provides end-to-end services for our biotech/pharma/or generic companies. Starting from clinical study design to the development of final study report. All services under one company including safety lab and PK analysis, biostatistical and data management, medical writing, project management, clinical monitoring, regulatory and consultation, IP packaging. Convex research organization successfully manage all steps of the way through the final results by an already proven and effective approch for every sponsor.