Experimental treatment takes end-run around cancer

Rebecca Hyman

Normally, when someone receives a stem cell transplant, it’s a bad thing if the patient rejects the donated cells.

But Ilene McBride’s doctors are hoping she’ll reject the stem cells she’ll receive from her mother on Dec. 30 and 31.

“We intentionally want her to reject the donor cells,” said McBride’s oncologist at Massachusetts General Hospital in Boston, Dr. Yi-Bin Chen, an instructor at Harvard Medical School.

McBride, who has Hodgkin’s lymphoma and has exhausted standard treatments, will be taking part in an experimental protocol to cure the illness in an end-run around the cancer that is threatening the life she loves and is determined to reclaim.

Chen said doctors had noticed that sometimes when patients reject stem cell transplants, a strong anti-cancer effect seems to accompany the rejection process.

Now doctors are hoping to harness that unintended but very welcome consequence by triggering an intentional rejection, Chen said.

Mass General is the only one offering the experimental treatment, and McBride will be just the fifth person to receive it.

“We don’t know the basis of it. That’s one of the reason’s we’re doing this study. I don’t think anyone expected when the graft was rejected to see the tumor go away as well, but it happened,” Chen said.

McBride, a Raynham wife and mother of two young boys, wouldn’t qualify for the treatment if she had any other options.

A long series of improbably bad outcomes has led her to this point.

When Ilene McBride was diagnosed with Hodgkin’s lymphoma in January 2007, she was told she’s one of the lucky ones. They were told it’s a “good” cancer to get, said her husband Tom McBride. Chen said the disease is curable 80 to 90 percent of the time.

Ilene McBride underwent six months of chemotherapy, but the cancer wasn’t completely knocked out, so that was followed by 21 days of radiation, at which point she went into remission.

Ilene McBride was packing for a family vacation to Disney World when she was first diagnosed.

The family decided to make that long-delayed trip in December 2007, nearly a year after the original plan was upended.

While she was there, she started to feel sick again. She had trouble picking up her little boys, then 2 and 4, she said.

“Everyone kept saying, ‘I’m sure it’s fine,’ but I knew it wasn’t,” Ilene McBride said.

Her cancer had come back.

Chen said about 80 percent of Hodgkin’s lymphoma patients are cured with these standard treatments, chemotherapy and radiation. But Ilene McBride found herself in the 20 percent.

The next step in her treatment was an autologous stem cell transplant in June 2008. That means her own stem cells were removed and then put back.

Chen said the point of this procedure is not the transplant itself. It is done to enable doctors to give the patient such a massive dose of chemotherapy it knocks out the blood count, which is “not compatible with life.”

The solution is to first remove the patient’s own stem cells to spare them the onslaught and then transfer them back in after the chemotherapy.

About 50 percent of patients are cured with an autologous transplant, Chen said. That’s half of the 20 percent of patients who needed it in the first place, leaving just 10 percent still searching for a cure.

In August 2008, Ilene McBride had a recurrence after a two-month remission.

“For people who relapse after that, there is no standard treatment,” Chen said.

But that doesn’t mean there aren’t any options, he said.

The next step for Ilene McBride was an allogeneic transplant, which means receiving someone else’s stem cells, ideally from a matching donor.

“An autologous transplant is all about the chemo,” Chen said.

But with an allogeneic transplant, “They get the donor’s immune system. The donor’s immune system grows up inside of them. It’s graft versus lymphoma,” Chen said.

The challenge is finding a suitable donor.

There’s a 25 percent chance a sibling will be a full match, a 50 percent chance a sibling will be a half match and a 25 percent chance a sibling will be a zero match, Chen said.

Ilene McBride has one sibling, a sister, who turned out to be a zero match.

But the donor doesn’t have to be a relative.

Twelve to 13 million potential donors are enrolled worldwide, Chen said. For a Caucasian patient, there is a 70 to 80 percent chance of finding a full match. For a minority, there is a 25 to 30 percent chance.

No match was found for Ilene McBride, who is white but Jewish, so some ethnic factors may have been at play, Chen said.

It is still possible to do an allogeneic transplant even in cases like Ilene McBride’s where no full match is available, Chen said.

There are two options: stem cells from umbilical cord blood of an unrelated person and stem cells from a “haploidentical” mismatched relative, which is a partially matched relative.

Chen said for subtle reasons the umbilical cord option was chosen for Ilene McBride.

In either case, the patient must be in at least partial remission.

A year ago, Ilene McBride was given four cycles of chemotherapy that got her into full remission and was ready to give the transplant a try.

But then she had a terrible adverse reaction to one of the chemotherapy drugs that triggered a month-long stay in the intensive care unit.

As she recovered, the disease relapsed.

“That was our window for a standard transplant, and we missed it,” Chen said.

Since then, doctors have been unable to induce another remission.

“The disease is very active, so we offered her an experimental transplant,” Chen said.

Her mother was selected as the donor instead of a stranger because Chen doesn’t want Ilene McBride to reject the stem cells too quickly. The transplant must begin to grow before it is rejected, he said.

He said the goal isn’t to wipe out Ilene McBride’s own bone marrow, as in a standard transplant, so she won’t be receiving a high dose of chemotherapy prior to the transplant.

That means her own immune system will still be functioning if all goes as planned and the donor stem cells are rejected – along with the cancer that has proven so difficult to eradicate.

Bridgewater Independent