Inclusion Criteria

Concurrent Medication:

Allowed:

• Antiretroviral therapy (at the discretion of the treating physician and/or medical monitor).

Patients must have:

• Presumptive or definitive diagnosis of Pneumocystis carinii pneumonia (PCP).
• HIV positivity or be otherwise immunosuppressed.
• Demonstrated intolerance and/or resistance to trimethoprim/sulfamethoxazole during the course of therapy for the current episode and not candidates for parenteral pentamidine, OR a documented history of such intolerance during a prior episode.
• Consent of parent or guardian if less than 18 years of age.

NOTE:

• In general, patients who meet the eligibility criteria for other U.S. Bioscience-sponsored clinical trials for trimetrexate would not be eligible for this Compassionate Use protocol.

Exclusion Criteria

Patients with the following prior conditions are excluded:

History of Type I hypersensitivity (i.e., urticaria, angioedema, or anaphylaxis), exfoliative dermatitis, or other life-threatening reactions to trimetrexate.