Inclusion Criteria:

- Patient must have been diagnosed with ovarian or primary peritoneal cancer

- Patient must have had 1 or 2 prior platinum-based chemotherapeutic regimens.

- Patient must have adequate health status.

- Patient compliance and geographic proximity that allow for adequate follow up is
required.

- Signed informed consent from the patient or legal representative is required.

Exclusion Criteria:

- Patient is pregnant or breast-feeding

- Patient has received treatment within the last 30 days with a drug that has not
received regulatory approval for any indication at the time of study entry.

- Patient has previously participated in another study investigating pemetrexed.

- Patient is unable or unwilling to take folic acid, vitamin B12 supplementation, and
corticosteroids.

- Patient cannot be taking nonsteroidal anti-inflammatory drugs around the time of
administration of study drug.