TORONTO - Ontario's ombudsman is launching an investigation into the province's funding of the chemotherapy drug Avastin to determine whether it makes sense to cap support for patients suffering from cancer.

The probe will review the Ministry of Health and Long-Term Care's policies for the drug, which is prescribed to colon cancer patients with funding limited to 16 two-week cycles -- regardless of patient response to the treatment.

"To many of the people who are taking this medication, Avastin is the last lifeline," ombudsman Andre Marin said Thursday.

The investigation was prompted by complaints from patients, as well as a letter from Progressive Conservative Joyce Savoline, that the "16-cycle limit appears arbitrary."

It will seek to determine why the government decided "drop the axe after 16 cycles," Marin said.

"To us it's more the systemic nature," Marin said. "It's a complaint which is rich in its quality and raises an issue which deserves to answered."

The Ministry of Health began funding Avastin in July 2008, when it committed $300 million over three years for the drug.

Clinical trials have shown Avastin is most effective as a first-line treatment for 16 weeks, and that's why funding was capped at that level, said ministry spokesman Andrew Morrison.

"It's an expensive drug and we made the decision to fund this drug for first-line treatment, based on scientific review of evidence where it's used in other jurisdictions as well as scientific data," Morrison said.

"We would be open to reviewing, re-evaluating that drug-funding policy based on a new clinical evidence as well."

The government will fully co-operate, Morrison added, noting the assistant deputy minister for Ontario public drug programs will meet with the ombudsman early next week.

As part of the investigation, the special ombudsman response team will conduct interviews with people affected by the restriction and review ministry documentation to determine why the decision was made.

Barry Stein, president of the Colorectal Cancer Association of Canada, said he considers the funding cap illogical.

"If the person is responding after the 16 cycles, it makes no sense whatsoever to deprive that patient of further medication because that means (the treatment is) stopping their cancer from growing or shrinking their tumour," Stein said.

About 22,000 Canadians are diagnosed with colon cancer each year -- 8,100 in Ontario.

Roughly 2,400 of the people diagnosed in the province are getting some kind of chemotherapy with or without Avastin, Stein said.

According to government figures, the average length of survival for people who receive Avastin with other chemotherapy is close to two years, compared to 15 months without the drug.

Savoline said she was glad to hear about the review because lifting the cap is the right thing to do.

"It's never a guarantee but it sure is good news," she said of Thursday's announcement.

"I'm hoping that because the ombudsman's office took it on that (patients) have some feeling of a success in the end."