New hope against cancer

I remember attending a conference on cervical cancer and, during a lull in the proceedings, turning to the Filipino doctors in our group (most of them OB-Gyns) and asking them if, should they be diagnosed with cancer, they would undergo chemotherapy.

To my surprise, most of them replied in the negative. “The best way to fight cancer,” said one, “is with your immune system. But chemotherapy destroys your immune system, so you are left with weakened weapons against the cancer.” Others conceded that while they might turn to chemotherapy, the side effects (nausea, a “burning” in the veins, and loss of appetite) could hasten the deterioration of one’s health.

When I asked the Philippine Charity Sweepstakes Office some years back for help with a relative’s chemotherapy, it outlined a list of requirements that must be completed with every chemo session. “We do not give the entire amount [for the full course of treatment],” an official told me. “This is because many patients choose to stop treatment after only a few sessions.”

I guess the saying about the cure being worse than the cause of illness applies to chemotherapy. The anticancer drugs work like carpet-bombing, turning one’s entire body into an inhospitable environment for cancer cells. The trouble is, and I don’t mean to be flippant about this, it could also turn your body into a hostile environment for your recovery or survival.

At a recent media orientation sponsored by Roche, a multinational firm that manufactures both diagnostic tools and cancer drugs, Dr. Sivabalan Sivanesan, Asia-Pacific “medical leader” for oncology, held up hope for a new class of anticancer treatments that use “targeted therapy,” or going after specific cancerous cells while sparing the rest of the body from the deleterious effects of drugs.

One of these involves harnessing the patient’s own immune system to go after specific cancer sites. More specifically, said Sivanesan, immunotherapy works by “inducing an infection to help arrest cancer growth.”

A problem with chemotherapy is that “over time you lose efficacy,” said Sivanesan. Chemo drugs may work to shrink the cancer cells at the start of treatment, but after repeated exposure to these drugs, the diseased cells become immune.

What new therapies like immunotherapy and the use of “biologics” — or drugs derived from biological (and not chemical) sources — do to fight cancer is to “slow down cancer growth,” said Sivanesan.

Biologics, derived from living cells, are “more complex than chemically-synthesized drugs,” according to Sivanesan. He likened the progress made in developing anticancer treatments as “going from riding a bike to riding a car and then riding a plane.”

“There has been tremendous transformational change since the late 1990s,” Sivanesan said, mentioning in particular Herceptin (the Roche brand name for trastuzumab), which interferes with the growth and spread of cancer cells in the body, most commonly in breast cancer and stomach cancer.

A study conducted by Mayo Clinic showed that the 10-year survival rate for breast cancer patients went from 62 percent to 74 percent for those on whom Herceptin was used in combination with other drugs.

The Roche manufacturing facility in Singapore that our group of journalists visited makes primarily Herceptin. But, Sivanesan said, in the years since Herceptin’s development, testing and approval, there have emerged what are known as “biosimilars,” which he described as “highly similar to the original product.” They are not mere “generic drugs,” Sivanesan added; they are made using the same process and ingredients after a drug’s patent has expired. Biosimilars, he said, are “intended copies” of biologic drugs that need to go through pharmacological analysis and reporting of adverse events from clinicians before being licensed.

In some countries in the region, said Sivanesan, guidelines on the manufacture of biosimilars are nonexistent and, thus, “poor copies of noncomparable biologics” are allowed to be marketed and used. But in the United States and Europe, use of biosimilars is not allowed.