T 0237/15 - Optimum dosage regimen is routine

Key points

• " The determination of the optimum dosage regimen required to achieve the therapeutic effect in the (human) patient is a matter of routine experimentation for the skilled person. Such routine tests do not require inventive skill and can consequently not establish an inventive step." 
• " The step from pre-clinical animal studies to clinical studies involving human patients is an unavoidable step when developing a new medicament. In the present case, the skilled person, aware of the complete disclosure of [D2], would take this step with a reasonable expectation of success. This expectation of success is based on the teaching of [D2], which discloses that SAHA was successfully used in the treatment of solid tumours in human patients (administered intravenously) [rather than orally as in the claim].  Consequently, a skilled person, in the knowledge that SAHA is bioavailable when given orally in animal studies [this is also described in D2] and having been given the information that SAHA achieves effective treatment in humans when introduced directly into the blood stream, would expect an effective treatment also for oral administration in human patients."

EPO T 0237/15 -  link

While the clinical trials with SAHA rely on intravenous administration of the drug (see reference 91 of document (2), which is on file as document (11)), the animal studies described in the passage on page 199, right-hand column, third paragraph, disclose successful treatment of rats or mice by oral administration of SAHA. In view of the effects achieved in these animal tests, i.e. the suppression of tumour growth in rats or mice, there remain no doubts that SAHA is bioavailable when given orally.

These animal studies are thus the most promising starting point in the assessment of inventive step. Since document (2) discloses specific studies involving SAHA, other parts of document (2) which relate to other HDAC inhibitors or discuss more general aspects are not relevant for the present decision.

4.3 The difference between the subject-matter of claim 1 of the main request [and D2] is thus the dosage regimen, in particular the dose, and, potentially, the type of patient.

Consequently, the technical problem is the provision of a treatment regimen for human patients based on oral administration of SAHA.

4.5 The problem has been solved. Reference is made to the data in the patent in suit.

4.6 It remains to assess whether the solution proposed in claim 1 of the main request is obvious.

4.6.1 The step from pre-clinical animal studies to clinical studies involving human patients is an unavoidable step when developing a new medicament. In the present case, the skilled person, aware of the complete disclosure of document (2), would take this step with a reasonable expectation of success. This expectation of success is based on the teaching of page 200, right-hand column, first paragraph, which discloses that SAHA was successfully used in the treatment of solid tumours in human patients (administered intravenously). Consequently, a skilled person, in the knowledge that SAHA is bioavailable when given orally in animal studies and having been given the information that SAHA achieves effective treatment in humans when introduced directly into the blood stream, would expect an effective treatment also for oral administration in human patients.

The determination of the optimum dosage regimen required to achieve the therapeutic effect in the (human) patient is a matter of routine experimentation for the skilled person. Such routine tests do not require inventive skill and can consequently not establish an inventive step.