The UK-based technology firm said that its board rejected the contract research organisation's (CRO's) offer as it believed the indicated value "materially undervalued the group and its prospects".
Upon confirming this week's failed takeover bid, Parexel said that while its preliminary proposal was rejected, it "is currently evaluating its options in relation to ClinPhone.
However, there can be no certainty that an offer for ClinPhone will be forthcoming".
"Any offer, if made, is likely to be solely in cash.
A further announcement will be made in due course", the firm said.
By attempting to buy ClinPhone, Parexel was looking to significantly build upon its own technology division, Perceptive Informatics, which includes medical imaging, clinical trial management systems (CTMS), interactive voice response systems (IVRS & IWRS) and services as well as other eClinical tools.
As the eClinical market gains momentum, business has been booming for ClinPhone - which specialises in the area of electronic data capture (EDC) - along with other prominent software providers in this emerging area of business.
Thomson CenterWatch's recent '2007 Survey of Investigative Sites in the US', identified EDC technologies as the number one area of potential for best preventing future delays in clinical trials.
Meanwhile, analysts have estimated that 20 per cent of clinical studies around the globe are now being conducted using EDC and predict a complete transition from paper based systems within a decade.
Over the past two years, ClinPhone has been expanding its presence across the US, opening new offices in California and North Carolina, as well as enlargening its existing facilities in Chicago and New Jersey.
Furthermore, as the Asia-Pacific region continues to be a hotspot for clinical trials activity, ClinPhone opened its first office in the region in late 2006 in the hope of gaining a head start.
From premises in Melbourne, Australia, the firm is now providing support to its existing Australian clientele as well as developing new business both within the country and the wider Asian markets, particularly Japan.
Things have not been all rosy for the firm, however.
Last year ClinPhone announced that its profits for the financial year ending 28 February 2008 "are likely to be significantly below market expectations" as a result of issues it encountered in the middle of the year.
Due to a number of disruptions caused by various third-party telecoms suppliers, as well as internal data processing issues, ClinPhone suffered operational difficulties in June and July which impacted the company's Randomisation and Trial Supply Management services to some customers, the firm said in a statement at the time.
ClinPhone said its emergency and disaster recovery procedures were able to "ensure service was maintained", albeit at a lower level of capacity.
It also stressed that those issues were external and out of its control.
"All of these issues have now been rectified and should not reoccur but the quality of service that the company was able to provide to customers during the period was affected.
This has led to a reduction in the forward order book, with a consequent impact on expected profitability in the current year," said ClinPhone.
ClinPhone added that the EDC market - the area in which the company specialises - is now moving toward a service model which recognises revenue over the duration of a clinical trial.
"The switch from a licence to a more services-based revenue model means that revenue is recognised over a longer period of time and will provide a recurring future revenue stream for the company."