Human papillomavirus genotype distribution in head and neck cancer: Informing developing strategies for cancer prevention, diagnosis, treatment and surveillance.

Current clinical practice algorithms for HPV testing make no effort to discern the impact of genotypes for patients with head and neck squamous cell carcinoma (HNSC). Data was collected for all patients with HNSCs that had undergone HPV testing at an academic hospital as part of clinical care (2012-2019). Screening was performed using real-time PCR targeting L1 of low and high-risk HPV types, followed by genotyping of positive cases. Genotype status was correlated with age, site and histologic parameters. Of the 964 patients tested, 68% had HPV-positive cancers. Most arose from the oropharynx (OP) (89%) and sinonasal tract (5%). The most frequent genotype was 16 (84.4%) followed by 35 (5.6%), 33 (4.1%), 18 (2.7%), 45 (1.1%), 69 (0.8%) and others (1.3%). There was an association between genotype (16 vs non-16) and tumor origin (OP vs non-OP) (p < 0.0001). HPV18 was associated with transformation to an aggressive small cell phenotype, but HPV16 was not (22% vs 0%, p < 0.0001). Patients with HPV-non-16 OP carcinomas were older than patients with HPV16 OP carcinomas, but the difference was not significant. HPV genotypes are variable and unevenly distributed across anatomic sites of the head and neck. The association of HPV18 with small cell transformation suggests that variants can track with certain phenotypes in ways that may account for differences in clinical behavior. This study challenges the prevailing assumption of HPV equivalency across all high-risk genotypes in ways that may inform preventive, diagnostic, therapeutic and surveillance strategies.

Standard of care vs reduced-dose chemoradiation after induction chemotherapy in HPV+ oropharyngeal carcinoma patients: The Quarterback trial.

BACKGROUND: Human Papillomavirus oropharyngeal carcinoma (HPVOPC) has better progression free (PFS) and overall survival (OS) than non-HPVOPC. Standard-dose chemoradiotherapy (sdCRT) results in significant acute toxicity and late morbidity. We hypothesized that after induction chemotherapy (IC), reduced dose chemoradiation (rdCRT) would result in equivalent PFS and OS compared to sdCRT plus IC in HPVOPC and would reduce toxicity. METHODS: Patients with p16+, previously untreated, locally advanced HPVOPC and ≤20 pack years smoking history received 3 cycles of IC with docetaxel, cisplatin and fluorouracil (TPF). Clinical responders who were HPV positive by type-specific PCR were randomized 1:2 to sdCRT (7000 cGy) or rdCRT (5600 cGy) with weekly carboplatin. The endpoints of the study were 3 year PFS and OS. RESULTS: 23 patients were enrolled, 22 were evaluable for TPF toxicity and 20 were randomized, 8 to sdCRT and 12 to rdCRT. Sixteen (80%) were HPV 16+ and 4 (20%) were other high risk (HR) variants. Fourteen (70%) had high risk features: T4, N2c, or N3. Median follow up was 56 months (range 42-70). Three-year PFS/OS for sdCRT and rdCRT are 87.5% vs 83.3% (log-rank test p = 0.85), respectively. All 3 failures are locoregional within 4 months of completion of CRT; 2 were in HR variants (50%). CONCLUSIONS: rdCRT after IC resulted in similar PFS/OS compared sdCRT. These data support Phase 3 clinical trials of radiation dose reduction after IC as a treatment strategy in HPVOPC. Molecular HPV with variant testing and smoking history are necessary for de-escalation trials.

Real-time PCR HPV genotyping in fine needle aspirations of metastatic head and neck squamous cell carcinoma: Exposing the limitations of conventional p16 immunostaining.

BACKGROUND: Given the propensity for HPV-positive head and neck squamous cell carcinoma (HPV-HNSCC) to metastasize to cervical lymph nodes, fine needle aspiration (FNA) plays an important diagnostic role in their initial detection. Indeed, there is now an unwavering commitment to HPV testing of FNAs even in the absence of clear methodologic guidelines and threshold criteria. A particular difficulty pertains to the interpretation of p16 staining. DESIGN: Data was collected for 210 patients with suspected regionally metastatic HNSCC that had undergone FNA as part of standard clinical care. Initial HPV screening was performed on cell blocks with real-time PCR using primers targeting L1 of high-risk HPV types. Additional genotyping was performed on HPV-positive cases. The results were compared to p16 staining and subsequent excisions when available. RESULTS: Of the 207 samples with sufficient DNA, 175 (85%) were HPV positive. HPV-16 was the most commonly detected genotype (90%). Of the HPV-positive cases, the primary site was the oropharynx (n = 154, 88.0%), supraglottic larynx (n = 2, 1.1%), nasal cavity (n = 1, 0.6%), hypopharynx (n = 1, 0.6%) or unknown (n = 17, 9.7%). On comparison with 31 paired surgical excisions, HPV status was concordant in all cases (100% correlation). Of 142 HPV-positive cases with matching p16 stains, p16 staining was reported as positive (n = 85, 60%), focal (n = 27, 19%), negative (n = 24, 17%) or non-contributory (n = 6, 4%); and only 33% reached the standard threshold limit (i.e. 70%) for HPV positivity. CONCLUSION: For patients with metastatic HNSCC, real-time PCR of FNAs reliably reflects HPV status, and is superior to conventional p16 immunostaining.

Treatment of oropharyngeal squamous cell carcinoma with IMRT: patterns of failure after concurrent chemoradiotherapy and sequential therapy.

BACKGROUND: The optimal management of oropharyngeal squamous cell carcinoma (OPSCC) is controversial. Modern radiotherapy typically employs intensity-modulated radiation therapy (IMRT), and herein, we report the Dana-Farber Cancer Institute (DFCI) experience with IMRT-based treatment of OPSCC. DESIGN: Retrospective study of all patients treated at DFCI for OPSCC with definitive or adjuvant IMRT between 8/04 and 8/09. The primary end point was overall survival (OS); secondary end points were locoregional control (LRC) and freedom from distant metastases (FFDM). Propensity score matching was used to create concurrent chemoradiotherapy (CCRT) and sequential therapy (ST) cohorts equally balanced for patient and disease characteristics. RESULTS: One hundred and sixty-three patients were included with 75% presenting with stage IV disease. Fifty-six patients (34%) were treated with ST. The three-year actuarial OS, LRC, and FFDM rates for the entire cohort/ST subset were 86%/89%, 86%/87%, and 88%/93%, respectively. There were no differences in OS, LRC, or FFDM between CCRT and ST in the propensity-matched cohort. CONCLUSIONS: IMRT was associated with excellent OS, LRC, and FFDM. Although the results following ST were superb, there was no obvious benefit to ST after adjustment for selection bias. We recommend that ST be reserved for medically fit patients with a high risk of distant metastases.

Survival and human papillomavirus in oropharynx cancer in TAX 324: a subset analysis from an international phase III trial.

BACKGROUND: The association between human papillomavirus (HPV) and overall survival (OS) in oropharynx cancer (OPC) was retrospectively examined in TAX 324, a phase III trial of sequential therapy for locally advanced head and neck cancer. METHODS: Accrual for TAX 324 was completed in 2003 and data updated through 2008. Pretherapy tumor biopsies were studied by PCR for human papillomavirus type 16 and linked to OS, progression-free survival (PFS) and demographics. RESULTS: Of 264 patients with OPC, 111 (42%) had evaluable biopsies; 56 (50%) were HPV+ and 55 (50%) were HPV-. HPV+ patients were significantly younger (54 versus 58 years, P = 0.02), had T1/T2 primary cancers (49% versus 20%, P = 0.001), and had a performance status of zero (77% versus 49%, P = 0.003). OS and PFS were better for HPV+ patients (OS, hazard ratio = 0.20, P < 0.0001). Local-regional failure was less in HPV+ patients (13% versus 42%, P = 0.0006); at 5 years, 82% of HPV+ patients were alive compared with 35% of HPV- patients (P < 0.0001). CONCLUSIONS: HPV+ OPC has a different biology compared with HPV- OPC; 5-year OS, PFS, and local-regional control are unprecedented. These results support the possibility of selectively reducing therapy and long-term morbidity in HPV+ OPC while preserving survival and approaching HPV- disease with more aggressive treatment.

Integrating systemic agents into multimodality treatment of locally advanced head and neck cancer.

Although highly debated in the 1980s, randomized clinical trials have provided undeniable evidence that systemic chemotherapy, as part of a multimodality treatment collaboration, is effective in improving survival, organ preservation and local-regional control in locally advanced head and neck cancer (HNC). We are entering an exciting period in which new chemotherapy agents, new paradigms of treatment, new surgical and radiation technology, and new prognostic factors are rapidly becoming available. Information on how to integrate these new tools and on how they affect long-term outcomes are lacking, making decision making and treatment planning more difficult. With unprecedented survival and the changing demographics of HNC we must now consider long-term consequences in addition to survival and local and regional control as important factors in therapeutic decision making. The availability of different treatment plans that incorporate systemic chemotherapy, radiotherapy and surgery give us many tools with which to craft a treatment for each individual patient. Today, in this exciting and chaotic period, a multidisciplinary and collaborative approach for each HNC patient at the start of decision making and planning is a necessity and the absolute standard of medical treatment for excellent patient care.

Phase I dose-finding study of paclitaxel with panitumumab, carboplatin and intensity-modulated radiotherapy in patients with locally advanced squamous cell cancer of the head and neck.

BACKGROUND: Panitumumab has the potential to improve the therapeutic ratio of concurrent chemoradiotherapy for squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: This phase I dose-finding study investigated escalating doses of paclitaxel (Taxol) given concurrently with panitumumab, carboplatin and intensity-modulated radiotherapy (IMRT) for stage III-IVB SCCHN. Untreated patients with oral cavity, oropharynx, larynx, hypopharynx or unknown primaries were eligible. Additional eligibility criteria included measurable disease, good performance status and no contraindication to therapy. Patients received weekly fixed doses of panitumumab and carboplatin plus escalating doses of paclitaxel with IMRT. RESULTS: Nineteen patients were enrolled on to two dose levels (DLs): weekly paclitaxel 15 mg/m(2) (n = 3) and 30 mg/m(2) (n = 16). One dose-limiting toxicity occurred in DL 2, which was declared the maximum tolerated dose. All patients experienced mucositis, primarily grade 3 or more. Oral pain, xerostomia, dysphagia, weight loss, dermatitis, nausea and acneiform rash were frequent. All patients had partial response according to RECIST, whereas the overall complete clinical response rate was 95%. At median follow-up of 21 months, 18 of 19 patients (95%) remained disease free. CONCLUSIONS: Panitumumab, carboplatin, paclitaxel and IMRT are well tolerated and appear highly active in the treatment of SCCHN. Further study of this regimen in SCCHN is warranted.

Sequential therapy for the locally advanced larynx and hypopharynx cancer subgroup in TAX 324: survival, surgery, and organ preservation.

BACKGROUND: Locally advanced laryngeal and hypopharyngeal cancers (LHC) represent a group of cancers for which surgery, laryngectomy-free survival (LFS), overall survival (OS), and progression-free survival (PFS) are clinically meaningful end points. PATIENTS AND METHODS: These outcomes were analyzed in the subgroup of assessable LHC patients enrolled in TAX 324, a phase III trial of sequential therapy comparing docetaxel plus cisplatin and fluorouracil (TPF) against cisplatin and fluorouracil (PF), followed by chemoradiotherapy. RESULTS: Among 501 patients enrolled in TAX 324, 166 had LHC (TPF, n = 90; PF, n = 76). Patient characteristics were similar between subgroups. Median OS for TPF was 59 months [95% confidence interval (CI): 31-not reached] versus 24 months (95% CI: 13-42) for PF [hazard ratio (HR) for death: 0.62; 95% CI: 0.41-0.94; P = 0.024]. Median PFS for TPF was 21 months (95% CI: 12-59) versus 11 months (95% CI: 8-14) for PF (HR: 0.66; 95% CI: 0.45-0.97; P = 0.032). Among operable patients (TPF, n = 67; PF, n = 56), LFS was significantly greater with TPF (HR: 0.59; 95% CI: 0.37-0.95; P = 0.030). Three-year LFS with TPF was 52% versus 32% for PF. Fewer TPF patients had surgery (22% versus 42%; P = 0.030). CONCLUSIONS: In locally advanced LHC, sequential therapy with induction TPF significantly improved survival and PFS versus PF. Among operable patients, TPF also significantly improved LFS and PFS. These results support the use of sequential TPF followed by carboplatin chemoradiotherapy as a treatment option for organ preservation or to improve survival in locally advanced LHC.

Human papillomavirus 6 seropositivity is associated with risk of head and neck squamous cell carcinoma, independent of tobacco and alcohol use.

BACKGROUND: The risk of head and neck squamous cell carcinoma (HNSCC) associated with common human papillomavirus types has not been well defined. METHODS: We conducted a case-control study of 1034 individuals (486 incident cases diagnosed with HNSCC and 548 population-based controls matched to cases by age, gender, and town of residence) in Greater Boston, MA. Sera were tested for antibodies to human papillomavirus (HPV)6, HPV11, HPV16, and HPV18 L1. RESULTS: HPV6 antibodies were associated with an increased risk of pharyngeal cancer [odds ratio (OR)=1.6, 1.0-2.5], controlling for smoking, drinking, and HPV16 seropositivity. In HPV16-seronegative subjects, high HPV6 titer was associated with an increased risk of pharyngeal cancer (OR=2.3, 1.1-4.8) and oral cancer (OR=1.9, 1.0-3.6), suggesting that the cancer risk associated with HPV6 is independent of HPV16. There was no association between smoking and alcohol use and HPV6 serostatus. Further, the risk of pharyngeal cancer associated with heavy smoking was different among HPV6-seronegative (OR 3.1, 2.0-4.8) and HPV6-seropositive subjects (OR=1.6, 0.7-3.5), while heavy drinking also appears to confer differing risk among HPV6-negative (OR 2.3, 1.5-3.7) and -positive subjects (OR=1.3, 0.6-2.9). CONCLUSIONS: There may be interactions between positive serology and drinking and smoking, suggesting that the pathogenesis of human papillomavirus in HNSCC involves complex interactions with tobacco and alcohol exposure.

The salivary microbiota as a diagnostic indicator of oral cancer: a descriptive, non-randomized study of cancer-free and oral squamous cell carcinoma subjects.

BACKGROUND: The purpose of the present investigation was to determine if the salivary counts of 40 common oral bacteria in subjects with an oral squamous cell carcinoma (OSCC) lesion would differ from those found in cancer-free (OSCC-free) controls. METHODS: Unstimulated saliva samples were collected from 229 OSCC-free and 45 OSCC subjects and evaluated for their content of 40 common oral bacteria using checkerboard DNA-DNA hybridization. DNA counts per ml saliva were determined for each species, averaged across subjects in the 2 subject groups, and significance of differences between groups determined using the Mann-Whitney test and adjusted for multiple comparisons. Diagnostic sensitivity and specificity in detection of OSCC by levels of salivary organisms were computed and comparisons made separately between a non-matched group of 45 OSCC subjects and 229 controls and a group of 45 OSCC subjects and 45 controls matched by age, gender and smoking history. RESULTS: Counts of 3 of the 40 species tested, Capnocytophaga gingivalis, Prevotella melaninogenica and Streptococcus mitis, were elevated in the saliva of individuals with OSCC (p < 0.001). When tested as diagnostic markers the 3 species were found to predict 80% of cancer cases (sensitivity) while excluding 83% of controls (specificity) in the non-matched group. Diagnostic sensitivity and specificity in the matched group were 80% and 82% respectively. CONCLUSION: High salivary counts of C. gingivalis, P. melaninogenica and S. mitis may be diagnostic indicators of OSCC.

Docetaxel induction therapy in locally advanced squamous cell carcinoma of the head and neck.

Patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN) are often treated with induction chemotherapy or chemoradiotherapy, but to date without major impact on survival. The combination of cisplatin-5-fluorouracil (5-FU) (PF) has been used as standard induction therapy; however, poor patient survival has stimulated investigation into new agents with potential activity in SCCHN. Docetaxel has significant single-agent activity in SCCHN and has been investigated in combination with PF regimens as induction therapy. The results of six phase II studies of docetaxel-PF regimens (TPF) as induction in locally advanced SCCHN patients are reviewed and reported. Consistently, high 2-year survival rates and overall response rates were demonstrated across the phase II trials in the range 42-82 and 71-100%, respectively. The toxicity profile seen with TPF-based regimens was acceptable. The primary toxicity was neutropenia, which together with gastrointestinal complaints accounted for the majority of adverse events. Given the encouraging phase II experience with TPF-based regimens, two large-scale phase III studies comparing TPF-based regimens with standard PF regimens are underway. The results have significant potential for validating the findings of the phase II studies, demonstrating improved survival and overall response of patients treated with docetaxel-based induction chemotherapy.

Postnatal pre- and postexposure passive immunization strategies: protection of neonatal macaques against oral simian-human immunodeficiency virus challenge.

Simian-human immunodeficiency viruses (SHIV) allow the evaluation of antiviral strategies that target the envelope glycoproteins of the human immunodeficiency virus 1 (HIV-1) in macaques. We previously protected neonates from oral challenge with cell-free SHIV-vpu+ by passive immunization with synergistic human neutralizing monoclonal antibodies (mAbs) (Baba et al., Nat Med 6:200-206, 2000). mAbs were administered prenatally to pregnant dams and postnatally to the neonates. Here, we used solely postnatal or postexposure mAb treatment, thus significantly reducing the amount of mAbs necessary. All neonatal monkeys were also protected with these abbreviated mAb regimens. Our results are directly relevant for humans because we used mAbs that target HIV-1 envelope glycoproteins. Thus, the large-scale use of passive immunization with neutralizing mAbs may be feasible in human neonates. The mAbs, being natural human proteins, can be expected to have low toxicity. Passive immunization has promise to prevent intrapartum as well as milk-borne virus transmission from HIV-1-infected women to their infants.

Phase I/II trial of outpatient docetaxel, cisplatin, 5-fluorouracil, leucovorin (opTPFL) as induction for squamous cell carcinoma of the head and neck (SCCHN).

The purpose of this study was to establish the maximum tolerated dose (MTD) of docetaxel in an outpatient docetaxel (T), cisplatin (P), 5-fluorouracil (5-FU) (F), and leucovorin (L) (opTPFL) regimen and to obtain preliminary assessment of opTPFL efficacy. Thirty-four patients with stage III or IV squamous cell carcinoma of the head and neck were treated with opTPFL. Docetaxel was escalated from 60 to 95 mg/m(2) in combination with 100 mg/m(2) cisplatin intravenous bolus, and 2,800 mg/m(2) 5-FU continuous infusion and 2,000 mg/m(2) leucovorin continuous infusion with prophylactic growth factors and antibiotics. Patients who achieved a complete (CR) or partial (PR) response to three cycles received definitive twice-daily radiation therapy. A total of 97 cycles were administered to 34 patients. The major acute toxicities were neutropenia and mucositis. The MTD of docetaxel was 90 mg/m(2) . Seventy-seven of 97 cycles of were administered on an outpatient basis. The overall clinical response rate to opTPFL was 94%, with 44% CRs and 50% PRs. The MTD of opTPFL is 90 mg/m(2) docetaxel. Outpatient administration of opTPFL is tolerable, feasible, and does not alter the ability to administer definitive radiation therapy on schedule.

Protection of neonatal macaques against experimental SHIV infection by human neutralizing monoclonal antibodies.

Neonatal macaques were completely protected against oral challenge with SHIV-vpu+, a simian-human immunodeficiency virus that encodes the envelope gene of a laboratory-adapted HIV strain, by pre- and post-natal treatment with a triple combination of human neutralizing monoclonal antibodies (mAbs). The mAbs were directed either against the CD4 binding site, a glycosylation-dependent gp120 epitope, or against a linear epitope on gp41. This triple combination was highly synergistic in vitro and neutralized primary HIV completely. Subsequently, oral challenge was performed with pathogenic SHIV89.6P, an animal-passaged variant of a chimeric virus that encodes the envelope gene of the primary, dual-tropic HIV89.6. Only post-natal treatment with a similar triple mAb combination was used. One out of 4 mAb-treated infants was completely protected from infection. In the other 3 treated animals, there was a tendency towards lower peak viral RNA loads compared with untreated controls. Two out of 4 mAb-treated infants maintained normal CD4+ T-cell numbers, in contrast to all controls that had steep declines at 2 weeks post-challenge. We conclude that the triple mAb combination significantly protected the neonates, even against mucosal challenge with pathogenic SHIV89.6P. Passively administered synergistic human mAbs may play a role in preventing mother-infant transmission of HIV, both against intrapartum transmission as well as against infection through breast milk. As passive immunization is a tool to assess correlates of immune protection, we conclude that the epitopes recognized by the mAbs in our combinations are important for AIDS vaccine development. Future passive immunization studies may reveal other important conserved epitopes.

Passive immunization against oral AIDS virus transmission: an approach to prevent mother-to-infant HIV-1 transmission?

To develop immunoprophylaxis regimens against mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission, we established a simian-human immunodeficiency virus (SHIV) model in neonatal macaques that mimics intrapartum mucosal virus exposure (T.W. Baba, J. Koch, E.S. Mittler et al: AIDS Res Hum Retroviruses 10:351-357, 1994). We protected four neonates from oral SHIV-vpu+ challenge by ante- and postpartum treatment with a synergistic triple combination of immunoglobulin (Ig) G1 human anti-HIV-1 neutralizing monoclonal antibodies (mAbs) (T.W. Baba, V. Liska, R. Hofmann-Lehmann et al: Nature Med 6:200-206, 2000), which recognize the CD4-binding site of Env, a glycosylation-dependent gp120, or a linear gp41 epitope. Two neonates that received only postpartum mAbs were also protected from oral SHIV-vpu+ challenge, indicating that postpartum treatment alone is sufficient. Next, we evaluated a similar mAb combination against SHIV89.6P, which encodes env of primary HIV89.6. One of four mAb-treated neonates was protected from infection and two maintained normal CD4+ T-cell counts. We conclude that the epitopes recognized by the three mAbs are important determinants for achieving protection. Combination immunoprophylaxis with synergistic mAbs seems promising to prevent maternal HIV-1 transmission in humans.

A phase II study of combined oral uracil and ftorafur with leucovorin for patients with squamous cell carcinoma of the head and neck.

BACKGROUND: The objective of this Phase II study was to define the response rate, safety profile, and toxicity of oral uracil and ftorafur (UFT) with leucovorin (UFT/LV) as a palliative treatment for patients with squamous cell carcinoma of the head and neck (SCCHN). METHODS: Patients with metastatic or recurrent SCCHN with an Eastern Cooperative Oncology Group performance status < 2 and adequate organ function were enrolled in an institutional review board-approved trial. Prior induction or adjuvant chemotherapy was permitted provided 6 months had elapsed since the last chemotherapy. Patients were treated with UFT 300 mg/m(2) per day and leucovorin 90 mg per day administered in three doses daily for 28 days followed by a 7-day break for a 35-day cycle. Planned intrapatient dose modifications were based on individual toxicity. Patients were removed from the study for progression of disease or unacceptable toxicity. RESULTS: One hundred six cycles of UFT/LV had been administered to 42 patients as of January 1, 2000. The most common toxicities, in descending order of incidence, were anemia, pain, fatigue, diarrhea, nausea, mucositis, and anorexia. Clinically significant toxicities attributable to UFT/ LV were primarily gastrointestinal. On an intent-to-treat basis, three patients (7%) achieved a complete response, and six patients (14%) achieved a partial response. The overall response rate was 21% (95% confidence interval, 10--37%). CONCLUSIONS: UFT/LV therapy is feasible in this patient population and is generally well tolerated. Response rates are similar to the rates expected with continuous-infusion 5-fluorouracil. UFT/LV should be studied further both alone and in combination therapy for patients with SCCHN.

Postnatal passive immunization of neonatal macaques with a triple combination of human monoclonal antibodies against oral simian-human immunodeficiency virus challenge.

To develop prophylaxis against mother-to-child human immunodeficiency virus (HIV) transmission, we established a simian-human immunodeficiency virus (SHIV) infection model in neonatal macaques that mimics intrapartum mucosal virus exposure (T. W. Baba et al., AIDS Res. Hum. Retroviruses 10:351-357, 1994). Using this model, neonates were protected from mucosal SHIV-vpu(+) challenge by pre- and postnatal treatment with a combination of three human neutralizing monoclonal antibodies (MAbs), F105, 2G12, and 2F5 (Baba et al., Nat. Med. 6:200-206, 2000). In the present study, we used this MAb combination only postnatally, thereby significantly reducing the quantity of antibodies necessary and rendering their potential use in humans more practical. We protected two neonates with this regimen against oral SHIV-vpu(+) challenge, while four untreated control animals became persistently infected. Thus, synergistic MAbs protect when used as immunoprophylaxis without the prenatal dose. We then determined in vitro the optimal MAb combination against the more pathogenic SHIV89.6P, a chimeric virus encoding env of the primary HIV89.6. Remarkably, the most potent combination included IgG1b12, which alone does not neutralize SHIV89.6P. We administered the combination of MAbs IgG1b12, 2F5, and 2G12 postnatally to four neonates. One of the four infants remained uninfected after oral challenge with SHIV89.6P, and two infants had no or a delayed CD4(+) T-cell decline. In contrast, all control animals had dramatic drops in their CD4(+) T cells by 2 weeks postexposure. We conclude that our triple MAb combination partially protected against mucosal challenge with the highly pathogenic SHIV89.6P. Thus, combination immunoprophylaxis with passively administered synergistic human MAbs may play a role in the clinical prevention of mother-to-infant transmission of HIV type 1.

Potent neutralization of primary human immunodeficiency virus clade C isolates with a synergistic combination of human monoclonal antibodies raised against clade B.

OBJECTIVES: We investigated the ability of several human neutralizing monoclonal antibodies (mAbs), originally raised against human immunodeficiency virus (HIV) clade B isolates, to neutralize primary clade C isolates as single agents and in combination. STUDY DESIGN/METHODS: HIV clade C isolates from five different countries were tested for susceptibility to neutralization by anti-clade B mAbs in human peripheral blood mononuclear cells. Monoclonal antibody combinations were evaluated for possible synergy. RESULTS: All 20 primary HIV clade C isolates could be neutralized 97.5% to 100% by a quadruple combination of mAbs IgG1b12, 2G12, 2F5, and 4E10. These mAbs recognized conserved epitopes and were highly synergistic, resulting in strong cross-clade neutralization. CONCLUSIONS: In our previous experiment, a synergistic combination of human neutralizing mAbs protected all macaque neonates against oral challenge with a simian-human immunodeficiency virus encoding HIV env. Together, our data suggest that passive immunization with currently available anti-clade B mAbs could play a role in preventing HIV clade C transmission through breastfeeding.

Docetaxel in squamous cell cancer of the head and neck.

Single-agent docetaxel induces a response in 21-42% of patients with recurrent squamous cell cancer of the head and neck (SCCHN). When used in combination with 5-fluorouracil (5-FU), response rates (RRs) of between 24 and 27% have been reported. In contrast, in combination with cisplatin, docetaxel has achieved a RR of 33% in previously treated patients and 86% in a subgroup of chemotherapy-naive advanced stage patients. The docetaxel/cisplatin combination appears to be highly active. High-dose induction chemotherapy for patients with locally advanced but potentially curable SCCHN is producing promising results: following combination therapy involving docetaxel, cisplatin, 5-FU and leucovorin (TPFL), RR are high and 75% of patients are alive at 2 years. Intermediate-dose induction chemotherapy involving docetaxel is also promising: the TAX 708 trial found an excellent 93% RR in 41 evaluable patients treated with docetaxel plus cisplatin and 5-FU (TPF). The rate of pathological complete response was also high. The toxicities with TPF therapy were similar to those seen with cisplatin/5-FU regimens without docetaxel. A phase III trial of this approach is currently being conducted.

Multicenter phase I-II trial of docetaxel, cisplatin, and fluorouracil induction chemotherapy for patients with locally advanced squamous cell cancer of the head and neck.

PURPOSE: We conducted a phase I-II, multi-institutional trial to determine the maximum-tolerated dose (MTD) of cisplatin in an induction chemotherapy regimen of docetaxel, cisplatin, and fluorouracil for squamous cell cancer of the head and neck (SCCHN) and to determine the safety, tolerability, and efficacy of the regimen at MTD. PATIENTS AND METHODS: A total of 43 patients with previously untreated, locally advanced, curable SCCHN were entered. Overall, 29 patients (67%) had N2 or N3 nodal disease and nine (21%) had T4 primary tumors. All patients received docetaxel 75 mg/m(2) on day 1; cisplatin at 75 (level I) or 100 (level II) mg/m(2) on day 1; and a continuous fluorouracil infusion at 1,000 mg/m(2)/d on days 1 through 4. Patients were treated with prophylactic antibiotics on days 5 through 15. Cycles were repeated every 21 days for a total of three cycles. Patients then received definitive therapy based on institutional preferences. RESULTS: Thirteen patients were treated at level I, and 30 patients were treated at level II. All 43 patients were assessable for toxicity. There were no major differences in toxicity between level I and level II. Cisplatin-associated grade 3 or 4 hypomagnesemia or hypocalcemia occurred in 13 (30%) and hearing loss in two patients (5%). Grade 3 or 4 neutropenia was observed in 41 patients (95%) and febrile neutropenia occurred in eight (19%). There was one serious infection (2%). There were 17 (40% [95% confidence interval [CI], 25% to 56%]) clinical complete responders (CR), 23 (54% [95% CI, 39% to 69%]) partial responders (PR), one (2%) with no change, and two (5%) unassessable patients. Major responses (CR, PR) were observed in 40 (93% [95% CI, 81% to 99%]) patients. Primary site CR was documented in 24 (54%) of patients. Postchemotherapy primary site biopsies were performed in 25 patients (58%) and pathologically negative biopsy was obtained in 11 (92%) of 12 primary site clinical CRs and seven (54%) of 13 with PR or no change. Overall, negative biopsies were obtained in 18 patients (72%). CONCLUSION: TPF induction chemotherapy can be delivered safely with a cisplatin dose of 100 mg/m(2) in previously untreated patients with SCCHN. The regimen is associated with a high rate of primary site clinical and pathologic CRs. Phase III comparison with cisplatinum and fluorouracil chemotherapy is warranted.