The UK-based company has entered agreements - each valued at $100,000 - with Merck, Johnson & Johnson's Belgium outfit, and Servier.
Vastox will use zebrafish to conduct blind screening of known compounds in order to evaluate the effectiveness of its technology in generating toxicity and teratogenicity data.
After three months, the pharma firms will assess the outcome of the pilot programme and whether the use of such technology is 'for them'.
"We are hoping to convince these firms that zebrafish could be a useful adjuvant to their preclinical screening and as a result, increase the size and breadth of the deals we now have in place," Darren Millington, Vastox CFO told Outsourcing-Pharma.com.
Millington said that although the firm would like to set up a royalty and milestone type deal, he expects any follow-on toxicity screening deals to realistically build up gradually, maybe in the form of bigger and longer pilots first, and continue on a fee-for service basis, as companies continue to assess the technology.
"We would expect to receive a fixed number of compounds from the client per week or month, however, and as this is a fairly newish technology for big pharma, more interaction is required between us and them than would be in a typical fee-for-service relationship."
The zebrafish technology can also be used to assist firms with efficacy studies, and if these types of deals were employed, the firm could expect to receive more of a stake in the product being developed, said Millington.
"This is because there is inherently more value in helping a company develop a compound, as opposed to just assisting them with deciding which compounds should be dropped due to toxicity."
Millington said the company has worked with six of the top ten pharma companies on zebrafish pilot programmes in some capacity in the past year, with "most of them" leading to follow-on work of some kind, although the three new pilot programmes recently announced are the first for six months.
In February, the firm also bagged two drug discovery deals with biotech companies worth a combined €1m after successfully completing pilot service contracts.
The first deal Vastox scored was with an unnamed European biotech company.
Vastox is providing it with medicinal chemistry and research services to support one of its new client's drug discovery programmes.
With this deal, Vastox will bag up to €635,000 over 10 months.
The company also entered a long-term drug discovery and toxicology screening contract with Rottapharm worth €365,000 over 12 months.
Under the terms of the deal, the two firms are collaborating on the generation of a screening model for osteoarthritis that will test potential drug candidates and therefore accelerate Rottapharm's discovery programme.
Vastox uses a chemical genomics approach for high throughput, small molecule in vivo screening in whole organism models, one of them based on zebrafish ( Danio rerio ) - a widely-used organism for genetic and developmental studies.
According to the firm, in many cases this approach generates data which is highly predictive of toxicity in mammals at a much earlier stage in discovery than with standard animal models such as rodents, rabbits and dogs, and as a result elicits cost savings.
"For example, in glaucoma, we have a fish model that gives us results in days or weeks, compared to the weeks and months that it takes with rabbit models, the current standard," said Millington.