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John H Barton

Publications and source records attributed to John H Barton.

11 recordsLinked to original sources

The patents-based pharmaceutical development process: rationale, problems, and potential reforms.

The pharmaceutical industry is facing substantial criticism from many directions, including financial barriers to access to drugs in both developed and developing countries, high profits, spending on advertising and marketing, and other issues. Underlying these criticisms are fundamental questions about the value of the current patent-based drug development system. Six major problems with the patent system are (1) recovery of research costs by patent monopoly reduces access to drugs; (2) market demand rather than health needs determines research priorities; (3) resources between research and marketing are misallocated; (4) the market for drugs has inherent market failures; (5) overall investment in drug research and development is too low, compared with profits; and (6) the existing system discriminates against US patients. Potential solutions fall into 3 categories: change in drug pricing through either price controls or tiered pricing; change in drug industry structure through a "buy-out" pricing system or with the public sector acting as exclusive research funder; and change in development incentives through a disease burden incentive system, orphan drug approaches, or requiring new drugs to demonstrate improvement over existing products prior to US Food and Drug Administration approval. We recommend 4 complementary reforms: (1) having no requirement to test new drug products against existing products prior to approval but requiring rigorous comparative postapproval testing; (2) international tiered pricing and systematic safeguards to prevent flow-back; (3) increased government-funded research and buy-out for select conditions; and (4) targeted experiments using other approaches for health conditions in which there has been little progress and innovation over the last few decades.

Developing Countries↗

Single-agent rituximab as first-line and maintenance treatment for patients with chronic lymphocytic leukemia or small lymphocytic lymphoma: a phase II trial of the Minnie Pearl Cancer Research Network.

PURPOSE: To assess the efficacy and toxicity of first-line single-agent rituximab, followed by re-treatment with rituximab at 6-month intervals, in previously untreated patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). PATIENTS AND METHODS: Forty-four previously untreated patients with CLL/SLL received rituximab 375 mg/m2 weekly for 4 consecutive weeks. All patients were required to have one or more indications for treatment. Patients with objective response or stable disease continued to receive identical 4-week rituximab courses at 6-month intervals, for a total of four courses. RESULTS: The objective response rate after the first course of rituximab was 51% (4% complete responses). Twenty-eight patients received one or more additional courses of rituximab. At present, the overall response rate is 58%, with 9% complete responses. After a median follow-up of 20 months, the median progression-free survival (PFS) time was 18.6 months, and the 1- and 2-year PFS rates were 62% and 49%, respectively. Treatment was well tolerated, with only two episodes of grade 3 to 4 infusion-related toxicity. No cumulative toxicity or opportunistic infections occurred. CONCLUSION: Single-agent rituximab, used at a standard dose and schedule, is active in the first-line treatment of patients with CLL/SLL, producing substantially higher response rates than previously reported in relapsed or refractory patients (51% v 13%, respectively). Re-treatment with rituximab at 6-month intervals is well tolerated. The PFS time of 18.6 months in patients with CLL/SLL seems shorter than the 36- to 40-month median PFSs previously reported with first-line plus maintenance rituximab in patients with follicular lymphoma. Additional follow-up is required to fully assess the impact of this treatment strategy.

Adult↗

Combination treatment with weekly docetaxel and gemcitabine for advanced non-small-cell lung cancer in elderly patients and patients with poor performance status: results of a Minnie Pearl Cancer Research Network phase II trial.

The purpose of this study was to evaluate the feasibility, toxicity, and efficacy of the combination of weekly docetaxel and gemcitabine in patients with advanced non-small-cell lung cancer (NSCLC) who are either elderly or have poor performance status (PS). Patients with stage IIIB or IV NSCLC who had received no previous chemotherapy and were = 70 years of age were eligible for this clinical trial. Patients < 70 years of age were also eligible if they had poor PS or were considered poor candidates for standard platinum-based combination chemotherapy regimens. All patients received chemotherapy with gemcitabine 800 mg/m2 and docetaxel 30 mg/m2, both drugs administered by 30-minute intravenous infusions on days 1, 8, and 15. Treatment courses were repeated every 28 days. Patients were reevaluated after completion of 2 treatment courses; responding patients continued treatment until disease progression or for a maximum of 6 courses. Between August 1999 and June 2000, 64 patients (73% with stage IV disease) were treated at 17 participating sites in the Minnie Pearl Cancer Research Network. Eighteen of 64 patients enrolled (28%) had objective response to treatment; an additional 25 patients (39%) had stable disease. Median survival was 7 months, with 1- and 2-year survival rates of 30% and 17%, respectively. Treatment was well tolerated by most patients. Grade 3/4 leukopenia occurred in 7 patients (11%), but no patient required hospitalization for neutropenia/fever. One patient developed fatal bilateral pneumonitis, which was possibly treatment-related. The combination of weekly docetaxel/gemcitabine is active and relatively well tolerated in most patients with advanced age or poor PS with advanced NSCLC. A randomized comparison of this regimen versus single-agent weekly docetaxel is in progress.

Age Factors↗

Prospective randomized study of four novel chemotherapy regimens in patients with advanced nonsmall cell lung carcinoma: a minnie pearl cancer research network trial.

BACKGROUND: The authors compared the toxicity, response rate, and progression free survival of four chemotherapy regimens for patients with advanced (Stage IIIB and IV) nonsmall cell lung carcinoma. METHODS: A total of 267 patients entered this randomized Phase II trial on one of four arms: paclitaxel, carboplatin, and gemcitabine (Arm A); paclitaxel, carboplatin, and vinorelbine (Arm B); paclitaxel and gemcitabine (Arm C); and gemcitabine and vinorelbine (Arm D). Patient characteristics were similar in all treatment arms. At the time of tumor progression, patients were removed from study and were treated at the discretion of their physician. RESULTS: Patients received a median of four courses of chemotherapy in all arms, and there was no difference in the dose delivered. There were no statistical differences in response rates (range, 32-45%), median progression free survival (range, 4.9-6.6 months), or progression free survival at 1 year (range, 8-19%). Actuarial survival in all four arms was not different, with a median survival ranging from 8.7 months to 10.7 months and a 1-year survival rate of 38-44%. Each arm was compared with a historic control with a median survival of 8 months. Arm D (gemcitabine and vinorelbine) approached significance at the 0.05 level. CONCLUSIONS: Two-drug combinations containing the newer drugs without a platinum drug were less toxic than three-drug, platinum-based regimens. There were no significant differences in objective response rates or progression free survival when the four regimens were compared. The two-drug combination of gemcitabine and vinorelbine was the least toxic and, thus, may be superior. A Phase III trial comparing combined gemcitabine and vinorelbine with combined paclitaxel, carboplatin, and gemcitabine is ongoing.

Adult↗

Gemcitabine, carboplatin, and paclitaxel for patients with carcinoma of unknown primary site: a Minnie Pearl Cancer Research Network study.

PURPOSE: To evaluate the efficacy and toxicity of the novel chemotherapy combination that includes gemcitabine, carboplatin, and paclitaxel in the treatment of patients with carcinoma of unknown primary site. PATIENTS AND METHODS: One hundred twenty patients were treated with the following regimen, administered every 21 days for a planned four courses: gemcitabine 1,000 mg/m(2) intravenously (i.v.) on days 1 and 8, carboplatin at an estimated area under the concentration-time curve of 5 mg min/mL i.v. on day 1, and paclitaxel 200 mg/m(2) i.v. on day 1. After four courses, stable and responding patients were given weekly paclitaxel 70 mg/m(2) i.v. for 6 weeks for three 8-week courses. All patients had relatively poor prognostic features. Sixty-three patients had well-differentiated adenocarcinoma, 56 patients had poorly differentiated carcinoma, and 104 patients had performance status of 0 or 1. RESULTS: Twenty-eight (25%) of 113 assessable patients (95% confidence interval, 22% to 30%) had major objective responses to treatment. Response rates were similar in the two major histologic types. Response rate did not seem to be improved by continued therapy with weekly paclitaxel. The median progression-free survival time was 6 months. Median survival for the entire group was 9 months, and the actuarial survival at 1 and 2 years was 42% and 23%, respectively. CONCLUSION: Combination chemotherapy with gemcitabine, carboplatin, and paclitaxel followed by weekly paclitaxel is an active and tolerable treatment for patients with carcinoma of unknown primary site. The survival seen in this poor-prognosis group of patients in this multicenter community-based trial is notable and similar to other taxane-based regimens for these patients. Study of additional combinations or sequences of newer drugs, as well as the exploration of targeted biologic agents for patients with an identified target in their tumors, is warranted.

Adult↗

Patents, genomics, research, and diagnostics.

Two kinds of currently available genomic patents may significantly interfere with medical research: (1) patents such as those on specific single nucleotide polymorphisms (SNPs), which may include claims that control the inference of phenotypic characteristics from specific genotypes, and (2) patents on computer-based genomic information, databases, or manipulation procedures. These will create more serious encumbrances than will patents on expressed sequence tags (ESTs). Two approaches should be considered vis-à-vis these genomic patents: (1) Reconsideration and redefinition of the recent extensions of patentable subject matter into more and more intangible areas. This could be pursued by legislation or by test litigation to seek Supreme Court reversal of certain of the decisions of the Court of Appeals for the Federal Circuit (CAFC). (2) A narrow legislative exemption protecting the ability to use SNPs and phenotypic-genotypic relationships in medical research, including contexts in which medical research and clinical practice are substantially intertwined.

Databases, Nucleic Acid↗

A phase I trial of weekly paclitaxel plus prolonged oral eniluracil/5-fluorouracil in patients with refractory malignancies.

PURPOSE: This phase I study was conducted to determine the dose-limiting toxicity (DLT), maximum-tolerated doses, and recommended phase II doses of the combination of weekly intravenous paclitaxel and oral eniluracil/5-fluorouracil (5-FU). PATIENTS AND METHODS: Patients received paclitaxel i.v. over 1 hour weekly for four consecutive weeks of each cycle. Oral eniluracil/5-FU was administered orally twice daily for 28 consecutive days starting on day 1 of each cycle. Cycles were repeated every 35 days. Patients were accrued at six different dosing combinations. Weekly paclitaxel doses ranged from 60 mg/m(2) to 80 mg/m(2), and oral eniluracil/5-FU doses ranged from 8.0/0.8 mg/m(2) to 11.5/1.15 mg/m(2) twice daily. RESULTS: Thirty-seven patients received 126 cycles of therapy. Myelosuppression was minimal at all dose levels, with no grade 4 neutropenia or thrombocytopenia reported. DLT was reported in three out of six patients enrolled at the highest dose level and consisted of grade 3 diarrhea (two patients) and grade 3 mucositis (one patient). No DLTs were reported in patients enrolled at lower dose levels. One complete response and three partial responses were reported in patients with taxane-resistant metastatic breast cancer. CONCLUSION: The combination of paclitaxel and eniluracil/5-FU was generally well tolerated. The recommended doses for further phase II testing are paclitaxel 80 mg/m(2) i.v. weekly for 4 weeks plus eniluracil/ 5-FU 10.0/1.0 mg/m(2) orally twice daily on days 1-28 with cycles repeated every 35 days.

Administration, Oral↗

Research-tool patents: issues for health in the developing world.

The patent system is now reaching into the tools of medical research, including gene sequences themselves. Many of the new patents can potentially preempt large areas of medical research and lay down legal barriers to the development of a broad category of products. Researchers must therefore consider redesigning their research to avoid use of patented techniques, or expending the effort to obtain licences from those who hold the patents. Even if total licence fees can be kept low, there are enormous negotiation costs, and one "hold-out" may be enough to lead to project cancellation. This is making it more difficult to conduct research within the developed world, and poses important questions for the future of medical research for the benefit of the developing world. Probably the most important implication for health in the developing world is the possible general slowing down and complication of medical research. To the extent that these patents do slow down research, they weaken the contribution of the global research community to the creation and application of medical technology for the benefit of developing nations. The patents may also complicate the granting of concessional prices to developing nations - for pharmaceutical firms that seek to offer a concessional price may have to negotiate arrangements with research-tool firms, which may lose royalties as a result. Three kinds of response are plausible. One is to develop a broad or global licence to permit the patented technologies to be used for important applications in the developing world. The second is to change technical patent law doctrines. Such changes could be implemented in developed and developing nations and could be quite helpful while remaining consistent with TRIPS. The third is to negotiate specific licence arrangements, under which specific research tools are used on an agreed basis for specific applications. These negotiations are difficult and expensive, requiring both scientific and legal skills. But they will be an unavoidable part of international medical research.

Developing Countries↗

TRIPS and the global pharmaceutical market.

This paper reviews the international controversy over patents and access to drugs in developing countries and explores the implications of the 1995 Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement, the 2001 Doha Declaration, and the 2003 agreement preceding the Cancun meeting. These agreements do not resolve the important funding issues that developing countries confront as they seek access to drugs. Also, the international debate and its resolution will complicate the importing of foreign pharmaceuticals into the United States and strengthen pressures both for expanding public support of U.S. drug purchases and, in the long run, for political control of U.S. pharmaceutical pricing.

Biomedical Research↗