Phase I Unit for Early Clinical Research

From first-in-human through proof-of-concept, including selected Phase II studies, our dedicated unit integrates study start-up, recruitment and clinical conduct.

Advanced facilities for early-phase clinical trials

Discover Clarenta’s Early Phase Clinical Research Unit in Sofia, Bulgaria. With more than 18 years of experience in Phase I and bioavailability/bioequivalence (BA/BE) studies, our purpose-built facility is one of the largest early-phase units in Southeastern Europe.

Our Early Phase Clinical Research Unit in Sofia is located within a university medical centre, providing direct access to experienced Principal Investigators and broader patient populations through physician referrals.

Our multidisciplinary team of physicians, nurses and specialists provides 24-hour coverage and weekend pharmacokinetic sampling. Structured processes and dedicated resources allow us to run studies in parallel while maintaining patient safety, quality and consistent execution.

With more than 300 completed studies, we support early-phase development through integrated services, efficient study start-up and clear accountability from planning to delivery.

Early-phase risks & Clarenta solutions

Work falls between teams

When the CRO, Phase I unit and external laboratories are not coordinated, every handoff creates another point where responsibility can become unclear.

One team holds the thread

We are the CRO and the site, and we coordinate the external laboratories supporting the study. Study management, site delivery and laboratory coordination remain connected, with clear accountability from start-up onwards.

Unclear scope leads to rising costs

When responsibilities are not defined early, unassigned tasks surface mid-study as scope discussions, change orders and delays.

Responsibilities agreed before work starts

We define who is accountable for each activity before the study opens, align terminology across the contract, and make the boundaries of scope clear from the outset.

Recruitment forecasts need evidence

Site questionnaires can tell you what might be possible. We would rather establish what is realistic before you commit.

We check the database before you sign

During the proposal phase, we assess your inclusion criteria against our healthy volunteer database and use that evidence to inform the recruitment plan.

You should know who is handling the issue

When questions move through layers of support, context gets lost and decisions take longer.

The same people stay close to your study

You have one project manager throughout, while the CRA involved in start-up continues into clinical monitoring. Questions stay with people who know the study, so issues can be understood and resolved quickly.

Key features of our Phase I Unit

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1,200 m²
dedicated unit
12 hospital beds
including intensive care beds
24-hour dedicated
medical team
24-hour emergency care
and equipment

A 360° view of our Early Phase Unit

Early phase studies we support

From first-in-human dose escalation to clinical pharmacology and proof-of-concept, our Phase I unit supports a broad range of early phase study designs.

First-in-Human Studies

Single and multiple ascending dose studies in healthy volunteers and patients, supported by 24-hour medical cover and intensive PK sampling.

Early Phase Oncology

Dose-escalation and expansion studies in patients, with access to experienced oncology investigators, established referral networks and integrated early-phase delivery in Sofia.

Proof-of-Concept Studies

Early patient studies designed to move from safety and pharmacology towards an initial signal of clinical activity.

Early Phase Development

Feasibility, protocol design and early development strategy from the same organisation supporting study delivery.

From our clinical leadership

Large organisations hide behind ticket services. You send a request to a help desk and, if you are lucky, you get an answer, but not a name. Here we know each other and we talk to each other, so a decision can be made within the hour rather than waiting for executives in another time zone.
Christopher Schlebusch
Global Head of Project Management & Clinical Monitoring

Why choose Clarenta’s Phase I Unit?

Early-phase expertise

Our dedicated Early Phase Unit brings specialist expertise to Phase I and bioavailability/bioequivalence (BA/BE) studies. We optimise study design, anticipate challenges and respond quickly when plans need to change, helping sponsors reach clear, data-led decisions sooner.

Faster trial start-up

Our integrated Early Phase Unit removes lengthy site contract negotiations and simplifies study set-up. Once approvals are in place, we can move quickly towards enrolment, reducing avoidable delays and keeping your development programme moving.

Faster patient enrolment

Our relationships with Principal Investigators and their referral networks provide access to wider patient pools. This helps us identify suitable participants sooner, maintain recruitment momentum and reduce avoidable delays.

Connected expertise

Our Early Phase Unit works closely with Clarenta’s regulatory, biostatistics, medical writing and clinical teams. This keeps decisions, study delivery and reporting connected, giving sponsors clear oversight throughout the trial.

Operational independence

Our Early Phase Unit operates independently from Clarenta’s CRO services. Clear governance protects scientific integrity, manages potential conflicts of interest and keeps decisions focused on the study’s clinical objectives and sponsor needs.

Parallel conduct of trials

Our Early Phase Unit can run multiple studies in parallel, supported by dedicated teams, careful resource planning and 24/7 medical oversight. This flexibility keeps overlapping and complex trials moving while maintaining quality, safety and control.
Plan your early-phase programme with our experts
The most useful conversation happens early, while the design can still change. Send us a protocol synopsis and we will tell you what the unit can deliver and when, including the parts we would question.