Sarah Jane Wilson & Ors. v Bayer Pharma AG & Ors.

Permission to reopen discontinued litigation requires a claimant to show a real change directly relevant to the claim and, at minimum, a real prospect of success. A plausible biological mechanism or statistical association does not, without appropriate expert support, establish causation on the balance of probabilities. Published scientific literature cannot replace properly served expert evidence.

Claims may constitute an abuse of process where they seek to relitigate issues previously investigated at substantial cost, have no real prospect of success, and lack a viable plan for funding, representation and trial. Striking out remains a remedy of last resort, but is appropriate in a clear and obvious case where further delay would merely prolong inevitable failure and cause disproportionate expense.

The claimants alleged that historical hormone pregnancy tests, principally Primodos and Amenorone Forte, caused congenital malformations, miscarriages and stillbirths. The proceedings included Mr Hyman, whose earlier claim had been discontinued in 1982 subject to an order requiring leave before further proceedings could be brought.

The defendants applied for refusal of leave in Mr Hyman’s case and for the remaining claims to be struck out as an abuse of process. They relied on the failure of the earlier test litigation, the absence of material scientific improvement, deficiencies in the pleaded and expert case on causation, and the lack of funding and legal representation. The central issues were whether Mr Hyman could demonstrate a real prospect of success and whether continuation of the wider proceedings was abusive and disproportionate.

1. Mr Hyman’s application. The words used by Bingham J in 1982 were not a formulaic test, but they identified the substance of the inquiry. The court had to consider the history and reasons for discontinuance, together with whether there had been a real change directly applicable to Mr Hyman’s case. He had to show, at least, that his claim now had a real prospect of success.
2. The evidence did not establish a prima facie case of individual causation. There was no expert evidence that Primodos caused, or could have caused, Mr Hyman’s heart defect, and no evidence excluding genetic causes. The evidence on generic causation remained materially similar to that considered in 1982. A plausible mechanism, including embryonic hypoxia and re-oxygenation damage, could not by itself establish a causal association.
3. Epidemiological evidence could form an important part of proof, but a statistically significant association did not itself prove causation in an individual case. The court would ordinarily expect experts to engage with the Bradford Hill guidelines or provide another properly supported basis for establishing causation. Selected scientific literature could not substitute for expert evidence.
4. Leave was refused. Requiring the defendants to relitigate the same issues, after substantial unrecovered costs had been incurred and without a real prospect of success, would be unjust.
5. The other claims. The order made in 1982 was not treated as binding on claimants who were not parties to that litigation. Their claims were nevertheless assessed under the principles governing abuse of process. The assessment required a broad merits-based judgment taking account of the public and private interests and all the circumstances. Striking out was a remedy of last resort and required a clear and obvious case, with proportionality considered as part of the overall assessment.
6. The proceedings sought to relitigate issues previously investigated, had not materially improved in the claimants’ favour, remained inadequately pleaded and supported on causation, and had no realistic plan for funding, representation or expert instruction. The claims therefore constituted an abuse of process. There was no proportionate alternative to striking them out, and the proceedings as a whole were struck out.